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Florida Institute of Technology

DMES: Naval Architect Design Team 150 W. University Blvd, Melbourne, FL 32901

Final Report Prepared For: Dr. Steven Wood, Senior Design Advisor

Prepared By:

Kevin Donnelly, Makemba McGuire, Andrea McAllister and Linzy Quandt

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22 July 2008

Design Team 4 M.A.H.I Technologies Department of Marine and Environmental Sciences Florida Institute of Technology 150 W. University Melbourne FL 32901 Dear Dr.Wood, Attached is the final report for our naval architecture design project. Our team, M.A.H.I. Technologies, is creating an innovative hull design for a standard displacement hull called D’M.A.H.I Mahi. This model will built from the ground up and tested against a control hull with no design alterations. We began this project by researching the dimple effect, golf ball performance, displacement hulls, and fluid mechanics. Our research has provided excellent assistance in understanding the mechanics behind fluid motion and how to model a prototype vessel proper set up. In completing this project we feel as though we have gained a deep understanding of these subjects. The following report contains detailed information about the background, theories, designs, and testing methods of our project. It also provides information regarding purchases, budget, timeline, results, and conclusions. At this point results have been inconclusive but suggest potential success arousing further investigation. The project is at an excellent position as we continue to more forward. If you have any questions, please do not hesitate to contact us. Sincerely,

Kevin Donnelly Makemba McGuire Andrea McAllister Linzy Quandt

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Executive Summary

On January 7th, 2008, we began our senior design project. Over the course of the semester,

our team has been researching and creating preliminary designs for this experiment. Our

main goal is to build working ship models from scratch. We have met with members of the

department and created design, building, and testing methodology. Our initial budget of

$1,250 has increased to $3,800.

The scope of this project is to study the effects on drag, created by a 191 foot coastal

carrier, through hull modification. Using both computational fluid dynamics as well as field

tests, we intend to prove that D’M.A.H.I Mahi design is more efficient than the current

standard displacement hull.

All results thus far have been inconclusive. Since construction is complete and research still

supports our theories, further investigation on the subject is to be made. Conclusive data

will either validate or dismiss our concept design.

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III. Table of Contents

I. Title Page

II. Letter of Transmittal

III. Executive Summary

IV. Table of Contents

V. Acknowledgements

VI. List of Figures

VII. List of Tables

VIII. Introduction

a. Motivations

b. Objectives

c. Organization

IX. Background

a. Historical

i. Golf Balls

ii. Displacement Hulls

b. Basic Theory

i. Naval Architecture

X. Procedures

a. Engineering Specifications

b. Computer Models and Analysis

i. Pro Surf

ii. Pro Engineer

iii. Fluent

c. Construction of the Physical Models

d. Testing

e. Budget

f. Safety and Precautions

XI. Results

XII. Discussion

XIII. Conclusion

XIV. Recommendations

XV. References

XVI. Appendices

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Acknowledgements

M.A.H.I Technologies Design Team would like to thank all those who have taken

part in this project. The computer modeling, research, and testing that we

performed raised many questions and without assistance, we would not have made

it this far. We would like to recognize Dr. Steven Jachec, Dr. John Sainsbury, Dr.

Steven Wood, and Alan Shaw for their knowledge and support throughout this

project.

We also appreciate all material, labor, and monetary donations we have received.

With out the extra assistance, this project would not be possible. For this we would

like to recognize Dr. Steven Jachec for providing us with addition grant funding from

Florida Institute of Technology, Eric Rohl of Structural Composites Inc. for donating

over twenty hours of CNC labor for our plugs, and Dave Catino for allowing us to run

tests using his facility at Regal Marine Industries.

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List of Figures

Figure 1- Featherie

Figure 2- Gutties

Figure 3- Flow Patterns of a Fluid Around a Sphere

Figure 4- Aerial View of Moving Vessel

Figure 5- Displacement vessel

Figure 6-NURB

Figure 7- Attempt one: Rendered View

Figure 8- Attempt one: Right View

Figure 9-Polyline Mesh

Figure 10-Surfaced

Figure 11-Shaped

Figure 12- Gaussian Surface

Figure 13- Pro Engineer Rendered Concept Hull

Figure 14-Patterned Revolve Cut

Figure 15-Dimples in Concept Hull

Figure 16- Whole Concept Hull Dimpled

Figure 17-Fluent Screen Shot 1

Figure 18- Fluent Screen Shot 2

Figure 19-Fluent Screen Shot 3

Figure 20-Makemba and Linzy using the Hot Wire Cutter

Figure 21-Removing First 3 inch Section

Figure 22- CNC Machine at Structural Composites

Figure 23-Plug Coated in Epoxy Resign

Figure 24-Sterm of Model Coated in Epoxy Resign

Figure 25-Sanding Down Thick Spots of Epoxy Resign

Figure 26-Applying Bondo to Plug

Figure 27-Applying Primer and Wet Sanding Plug

Figure 28-Applying Mold Release Agents

Figure 29-Spraying on the PVA

Figure 30-Applying the Tooling Gel Coat

Figure 31-Trimming the Flange

Figure 32-Tryng to Release the Plug from the Mold

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Figure 33-Pulling Out the Plug

Figure 34- Fiberglass Laid in the Mold

Figure 35- First Part Released from the Mold

Figure 36- Final Control Hull Model

Figure 37- Test Tank Facility at Regal Marine Industries

Figure 38-Actual Test Tank and Towing Beam Used for Experiment

Figure 39- Metal hook for Towing Mechanism

Figure 40-S-Type Load Cell

Figure 41- Data Logger for Load Cell

Figure 42- R-232 to USB Cable

Figure 43-Screen Shot of HyperTerminal

Figure 44- Model and Towing Mechanism Set up

Figure 45- Trial 1 Data from Control Hull Model Test

Figure 46- Trial 3 Data from Control Hull Model Test

Figure 47- Trial 3 from Concept Hull Model Test

Figure 48- Trial 10 from Concept Hull Model Test

Figure 49- Photo Capture 1 from Control Hull Model Video

Figure 50- Photo Capture 2 from Control Hull Model Video

Figure 51- Photo Capture 1 from Concept Hull Model Video

Figure 52- Photo Capture 2 from Concept Hull Model Video

Figure 53- Photo Capture 3 from Concept Hull Model Video

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List of Tables

Table 1-Vessel Particulars

Table 2-Half Ordinates

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Introduction

Motivations

As a group interested in Naval Architecture, our main goal for this project was to

design and construct a boat from scratch. Our interests lied primarily with the

building process required to produce a fiberglass vessel. Needing a reason, we

developed a theory that states; if the principles that make a golf ball travel further

than a smooth ball are applied to displacement hull, we could potentially reduce the

drag and increase the efficiency of the vessel.

Objectives

Our objective was to modify the hull of a 191 ft costal carrier in the same way a golf

ball is modified from a smooth ball. Utilizing CFD, we attempted to model multiple

concept designs and conclude which dimpling pattern best reduces drag by

reattaching flow. Both the concept and standard designs were created into physical

models using fiberglass construction materials for in water field testing. Conclusions

were made on the effects of dimpling and its relationship to drag and efficiency.

Organization

With only four group members organization was essential. Each group member had

taken responsibility for specific areas throughout the project. Information acquired

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as individuals was then passed on to the entire group. Linzy was responsible for

background information, paperwork, and testing. AJ was responsible for safety

management and weekly reports. Kevin was responsible for computer modeling and

budget. Makemba was responsible for CFD analysis. All group members contributed

towards construction.

Background

Golf Balls

In 1456 A.D. in Scotland the first game of golf was played and like all games, it

developed and soon its impedimenta became improved. It is

believed that the first golf balls were made out of wood. As the

game developed, the “Featherie” was invented in 1618. This ball

consisted of tightly packed into cow hide that was formed into a

sphere when wet. Unfortunately, this ball was expensive and was not affordable by

the masses. So by 1848 a new golf ball was developed, the “Guttie.” With a

completely new approach, the Guttie was created from a rubber like sap from the

Gutta tree found in the Tropics. When the rubber was

heated, it could easily be molded into a perfectly round

sphere with a nice, smooth surface. This ball was easily

produced, and easily fixed by simply reheating. At first it

seemed like a great new design. However, golfers soon

realized that it did not travel as far nor soar through the air as well as the Featherie.

Fig. 1-Featherie

Fig. 2-Gutties

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Overtime, golfers discovered that the old, battered Gutties began to perform as the

Featherie had. Post 1880, the newly manufactured Gutties were seen with a variety

of patterns on the surface in an attempt to recreate the distance characteristics of

the Featherie. It is during this revelation, that the first signs of dimpled golf balls

were seen.

As the industrial revolution carried on, machines and molds were developed which

allowed for mass production of Gutties. The first notable pattern as called the

“Bramble” and consisted of raised spheres as visible in Figure 2. As the handcrafted

ball came to an end, more and more patterns were tested. In 1905, the modern day

dimple pattern was designed by William Taylor. Like the scaring on the balls, the

dimples serve to alter the surface of the ball and therefore change the direction of

the air around the golf ball. Scientists refer to this anomaly as the dimple effect. To

understand why the dimple effect increases the travel of the golf balls, one must

understand a bit of fluid mechanics.

As a fluid such as air contacts a sphere, the fluid bends around the sphere while

remaining in contact with the surface. However, the fluid does not remain in

contact with the entire surface of the sphere. A fluid such as air or water

surrounding any object can only do so for a given amount of time until it separates

from that body. The location where the fluid breaks contact with the surface is

called the point of separation. Figure 3, B and C, illustrate this concept with respect

to a smooth surfaced spherical object. Notice that the point of separation occurs at

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or near 90° from the stagnation point. Figure 3A illustrates this concept with respect

to a rough surfaced spherical object, such as a golf ball.

Fig. 1- Flow Patterns of a Fluid Around a Sphere

As the air travels over a smooth ball, the flow is laminar. Comparatively as it travels

over a dimpled ball it becomes turbulent. One may assume that a turbulent

boundary layer would result in more friction and hence ebb the balls flight.

However, as the skin surface friction is increased the dimples serve to reattach the

air on to the ball for a longer time. In turn, the point of separation moves to a

location about 135° from the initial point of contact as shown in Figure 3A.

As you further examine Figure 3, you can actually compare images B and C to flow

around a displacement hull. This is because water and air both behave similarly, and

the shape of a displacement hull is similar to the curvature of a golf ball. If you look

at a moving vessel from above as in Figure 4, you will see a similar pattern created in

the water near the stern of the vessel as you see behind the spheres. The rough,

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bubbly water you’re observing is caused from the eddies projected from the point of

separation as shown in Figure 3B.

Fig. 2- Aerial View of Moving Vessel

It is for this reason that we believe the same concept of the dimple effect used on a

golf ball can be applied to a displacement hull.

Displacement Hulls

Generally speaking, there are two distinct hull forms: planning and displacement.

Planning hull designs are used for

high speed craft and also your

common recreational watercraft.

Their general hull shape has a sharp

bow and box like stern. There is

really no significant curvature to the

design. Without the curvature, there is no point of separation that occurs on the

hull. The water separates from the vessel when the hull ends. This does not provide

us with any surface area on the hull behind the point of separation where we can

Fig. 3-Displacement Vessel

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attempt to reattach the flow. This is why we chose not to model a planning hull.

However, a displacement hull has a rounded tear drop shape from bow to stern. As

previously mentioned, this apparent curvature allows use to apply the same dimple

effect that is used on a golf ball on a displacement hull model. A displacement hull

is a very common hull form and is used for the majority of large shipping vessels

such as freighters, tankers, and cargo carriers. The design of displacement hulls

allows for the most efficient, long distance, safe travel at this present moment. The

defining characteristic of a displacement hull is that the weight of water displaced is

equal to the weight of the ship. As a result and due to Newton’s 3rd Law, the water

provides an opposing upwards thrust while traveling at varying speeds or while

resting. However, it is important not confuse this with hydrodynamic lift which

means it does not lift out of the water as speed increases. The ship is actually

experiencing hydrostatic support corresponding to Archimedes principle. That

supports why this hull formation is generally heavy and not designed for high

speeds. Consequently, these vessels are very seaworthy because they move

through the water rather than on top of it. As a displacement hull vessel moves

through the water in a plowing motion, it is the actual hull design doing most of the

work. The engines in displacement hull vessels are quite small compared to the size

and weight of the ship. The amount of power being provided by the engine has no

significant effect on the speed of the ship. In fact, the determining factor in the

maximum hull speed of a displacement hull vessel is determined by the square root

of the waterline length. Also the waterlines, or drafts, must indicate the ships

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loading condition. This means that the weight of the ship is established equivalently

for a given loading condition. These are the markings that you can see on the bow

and stern of displacement hulls. As you add more power to these vessels the speed

will not increase. Instead, you will only burn more fuel and cause cavitations. The

requirement for only small engines to propel such large ships is what allows these

vessels to be ideal for traveling long distances. Another benefit of require small

engines is that it frees up interior space providing a greater capacity of material for

transport.

However they are extremely slow and as previously presented even at the maximum

power the speed and efficiency leaves a lot to be desired. Although they may be

the most efficient for their tasks right now, we feel there is room for improvement.

Since the hull design does most of the work for these vessels, we think that

improving the hull design in the best way to increase the efficiency. By applying the

theory of the dimple effect and actually designing a displacement hull with dimples,

we believe we can reattach flow, reduce drag, and increase efficiency. With the

current energy crisis the world is facing, fuel efficiency is becoming the new focus of

many innovative designers. Increasing the efficiency of one of the most used forms

of trade and transportation could have major positive economical and

environmental effects. It is for the reason that we feel if this project yields

conclusive results we may have made a significant discovery and cutting edge

design.

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Naval Architecture

The principle of using small models to test large ideas has been in existence for quite

some time. However, many attempts to use models have not been successful. It is

important to ask “with what degrees of accuracy does the model represent the

behavior of the larger prototype?” This question reiterates the importance of the

model size and technique of tank testing. For this reason, we used an existing lines

plan to create the 3D computer model of a displacement hull from which our actual

fiberglass models would be created. Models of varying sizes but identical shapes are

known as “similar models.” However, it is not only the shape that determines the

type of vessel. Modeling a 191’ Coastal Carrier involves much more than making it

the same shape, but rather have comparable theoretical values. The important

value that we focused on for this experiment was the 18 foot water line. All of the

computer analysis we complete was focused on the 18 foot water line. In order to

have our models float at the 18 foot water line, we had to sink the vessels down by

using sand bags and make the boats weigh 135 pounds. Another value that we

compared was the maximum velocity that can be experienced by a displacement

hull. The standard formula is 1.34xlength of the loaded water line. For our model,

this equals 5.9 feet per second.

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Procedures

Computer Models and Analysis

ProSurf 3

A product of New Wave Systems, Inc., ProSurf 3 is a three dimensional surface modeling

program specific to hull rendering and fairing. Like many surfacing programs, it uses NURBs to

create complex surfaces. Stephen M. Hollister, founder of New Wave Systems, Inc. defines

NURBs and their history as, “…Non-Uniform, Rational, B-splines. They are equations used to

define curves or surfaces that simulate the designer's batten in terms of stiffness and

continuity. In the early 1970's, 'B' or Basis splines were created (There are an infinite number of

splines.) as a convenient way to define smooth curves and surfaces interactively on the

computer screen. Rather than have a curve pass through a set of points, like ducks on a batten,

a B-spline creates a curve which is "influenced" by the positions of defining points called

vertices (see figure below). The designer changes the shape of the curve by changing the

positions of the defining vertex points.”

Fig. 4-NURB

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The equation used to create a NURB is as follows,

P(i,j) Matrix of vertices: nrows=(k1+1) ncols=(k2+1)

W(i,j) Matrix of vertex weights: one per vertex point

bi(s) Row-direction basis or blending polynomial functions of degree M1

bj(t) Column-direction basis or blending polynomial functions of degree M2

s Parameter array of row-direction knots

t Parameter array of column-direction knots

The use of NURBs allow for the creation of complex surfaces, like the hull of a vessel.

Understanding the function and limitations of NURB surfaces allows the end user to

create accurate models. Fairing allows the user to create models accurate enough

for use in construction. By outputting lines characterizing the second derivative of

the surface, the program locates unwanted points of inflection. In other words, the

program highlights and magnifies any bumps or wiggles in the surface so the user

can eliminate them if so wanted. This allows for the achievement of the smoothest

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surfaces possible while maintaining the desired shape. ProSurf 3 will be used to

create the 3D model of our boat hull.

Lines Plan:

To ensure the vessel designed was truly a displacement hull, it was based on the

lines plan of a displacement hull provided in the appendix. This eliminated the

possibility of unexpected error due to improper vessel characteristics. The vessel is a

costal carrier baring the design dimensions found in Table 2.

L.B.P 191 ft. Breadth Molded 34 ft.

Draft Molded 13.5 ft. Depth Molded 20 ft.

Molded Displacement 442.5 tons Extreme

Displacement

446 tons

Table 1-Vessel Particulars

Control Design with ProSurf 3:

A three dimensional model of the vessel is to be created, using ProSurf 3, for later

use in Fluent and Gambit. This model will provide the means necessary to determine

the characteristics of the vessel (coefficients of drag, area of separation, etc.) that

can then be compared to our concept designs. Defining the standard boat hull as our

control allows us to compare the results produced by our concept designs to make

conclusions. Accuracy in the model is top priority. Any imperfections at this point in

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the design would provide a source of error for the entire project. These models will

also be used to create the tool paths required for CNC. Any imperfections here

would necessitate hand faring later when using foam plugs to create molds.

To create a 3-D model from a lines plan the half ordinates must be determined. The

lines plan provided contained no scale so one was created. Since the vessel is 191 ft

between perpendiculars, this means each ordinate represents 19.1 ft. The measured

distance between each ordinate was 2.85 cm. A simple ration would yield,

ftcm

ftcm

701754.61

1.1985.2

In other words, each centimeter measured on paper is equal to 6.701754 ft. This

makes 6.701754 ft/cm the scaling factor for the lines plan.

The half ordinates at each waterline were measured. The results were recorded in

Table 3 on the following page.

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Ordinate (ft) Water lines

2 ft 4 ft 6 ft 12 ft 18 ft

A n/a n/a n/a 0.670175 6.701754

0 n/a n/a n/a 3.685965 8.71228

0.5 0.670175 1.005263 1.34035 8.042105 12.3982

1 2.345614 3.685965 5.696491 11.39298 14.07368

1.5 4.691228 6.701754 8.712281 13.40351 14.74386

2 7.707018 10.05263 11.72807 14.60983 15.41404

3 13.40351 14.74386 15.41404 15.74912 16.08421

4 15.07895 16.08421 16.08421 16.08421 16.4193

5 15.41404 16.4193 16.4193 16.4193 16.4193

6 15.07895 16.08421 16.08421 16.4193 16.08421

7 13.06842 14.40877 14.94491 15.74912 16.08421

8 8.846316 10.72281 11.39298 13.40351 14.74386

8.5 6.031579 7.707018 8.712281 10.72281 12.73333

9 3.350877 4.691228 5.361404 7.036842 10.05263

9.5 0.804211 1.541404 2.010526 3.350877 6.031579

10 n/a n/a n/a n/a 1.340351

Table 2-Half Ordinates

First Attempt

The initial attempt in designing the 3-D model had each waterline and ordinate

defined as a row/column. Each waterline was fixed horizontally on the x-y plane;

therefore each line representing a waterline would bare the same z-coordinate.

Each ordinate was fixed vertically on the y-z plane; therefore each line representing

an ordinate would bare the same x-coordinate. The points created by the

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intersection of the rows and columns were moved to the positions of the half

ordinates. The program then creates the symmetric counterpart.

This method yielded many errors. Ordinates A, .5, and 10 were unable to be created

because they did not cross every waterline. This can be seen by the values not

available in the chart above. The program would not allow for the creation of a fixed

vertical line that did not pass through all horizontals. This left portions of the bow

and stern misshaped because the associated half ordinates could not be entered.

This can easily be seen in Figure 7.

Fig. 5- Attempt one: Rendered View

In addition, due the functionality of NURB’s, the round bilge design of the vessel was

severely deformed. This can be seen in Figures 7 and 8 very clearly. In an attempt to

correct these deformities, additional row/columns were added. By altering the Surf

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around the imperfection, the user can sometimes corrects what the computer

outputs. After many hours of alteration, success was not achieved.

Fig. 6- Attempt one: Right View

Second Attempt

The second attempt differed from the first attempt in that it did not start with a

Surf, but rather the Surf was created. Attempt one tried to alter an existing Surf into

the desired specification of our coastal carrier. Here, a three dimensional model of

the boat was created using polylines. These polylines would be used to define the

surface, creating the Surf. This is a process known as Reverse Engineering. The

program, normally used for free lance designing, is being used to create something

that is already been designed.

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To start, the keel was defined on the x-y plane at z=0 with its after most point at the

origin. Waterlines were then added individually. Each waterline contained the same

number of points as ordinates it did cross. The x, y, and z values for each point were

then defined as seen in Table 3. These points were originally defined as knuckles,

but were CurveFit for smoothness. With Snap ON activated, the ordinates were then

drawn by connecting points of common x value. Again, the program creates the

symmetric counterpart. The resulting 3-D mesh can be seen in Figure 9.

Fig. 7-Polyline Mesh

The next step in this process is to use the created mesh to define the surface. This

was done with the Skin/Loft Surf feature. The order and direction in which curves

are selected for skinning changes results. Originally, waterline curves were selected,

starting with the deck line and ending with the keel. This resulted in an extremely

similar outcome as attempt one, the rounded bilge of the boat being severely

deformed. This selection order was disregarded.

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Next, ordinate curves were selected from bow to stern. Since some ordinate curves

shared points with other curves (A, .5 and 10), the Skin/Loft Surf tool would try to

skin the same point more than once. This would create bow ties in the NURB’s, in

turn creating holes in the defined surface. Although this was still a problem, the

rounded bilge was no longer an issue.

After technical support from New Wave Systems it was recommended that the

mesh be surfaced from bow to stern, but not including the curves creating the

problems. The next step would be similar to what a lofts man does on the loft floor,

to interpret the shape of the bow and stern based on the information at hand. The

three dimensional polyline mesh would provide a reference when shaping the bow

and stern. Figure 10 shows where the blue surface needed to be shaped to meet

the green curves and to eliminate any imperfections, like the ones found towards

the stern. This step was essential in developing an accurate model.

Fig. 8- Surfaced

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Additional columns were added in the bow and the stern to allow for shaping.

Utilizing the different views in the program made it easier to shape the surface to

that of the polyline mesh. After many hours of shaping, Figure 11 shows how the

blue surface now very closely matches the shape of the green mesh, unlike in Figure

10.

Fig. 9-Shaped

The final and most time consuming step in creating an accurate 3-D model is the

fairing of the hull. K-curves were activated for each horizontal line. The K-curves

were then faired with a K-scale factor of 25. The vertical lines were faired next. This

was performed for all lines in both the Back and Bottom views. This process was

then repeated several times to achieve the smoothest hull possible. Figure 12 is a K-

patch Gaussian surface of the final computer model. Shades of blue represent

smooth surfaces while shades of yellow and red represent less smooth surfaces. The

least smooth surfaces exist where the most shaping occurred. These are also the

areas where the most fairing was required.

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Fig. 10- Gaussian Surface

Pro Engineer

Pro Engineer is in many ways the mechanical engineering equivalent of ProSurf.

Where ProSurf is capable of modeling hulls, ProE is capable of modeling various

mechanical elements. In the Case of the Mahi mahi, one may wonder the purpose

of using Pro E? Due to its difference and greater bevy of design tools, Pro E allows us

to alter the design of the “ProSurf hull” to add the most import analysis element, the

dimples on the hull. The true purpose of the final analysis is to assess the efficiency

of a dimpled hull compared to a standard displacement hull. Therefore the purpose

of Pro E is to add the dimples in various arrangements on different hull prototypes

for further analysis.

The surface created in ProSurf 3 was imprted into Pro E. This allowed for

modification to create the concept hulls. These hulls would then also be exported

and run through Gambit and Fluent for fluid analysis. These results would be

compared before choosing the best concept design to create a physical model.

Original thoughts had the dimple designed as a part. A hole for each dimple would

be extruded from the surface and the dimples assembled into the holes. To mimic

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the design of a golf ball, the radius of the dimple would be 7% the radius of the

round bilge. The depth of the dimple would be 7% of its own diameter. The round

bilge having a radius of approximately 6.03 ft, the radius of the dimple would then

be .42 ft with a depth of .06 ft (7/10”). This aspect of design is subject to change in

order to achieve maximum results.

A part assembly for each dimple was decided to be very time consuming and

unrealistic. After a consult with Mr. Willard, the solids modeling instructor, it was

decided the dimple would be created using a revolve cut. This eliminated the need

to assemble each dimple to the hull while allowing it to maintain the same

dimensions. This revolve cut could then be patterned over the surface of the hull

making the entire process faster and much more painless.

After defining planes in the x,y, and z directions, the surface was thickened to allow

for revolve cuts. It was made certain that the surface was thickened inward as to not

affect the geometry of the outer hull. In order for the thicken feature to work, the

.iges file needed to be imported without its symmetric part. The full hull can be

created after modification by using the mirror part tool and assembling the two

together.

The Dimple

The vessel was to be dimpled from the greatest water line and below. Therefore, a

datum point was created on the surface eighteen feet above the keel. A datum axis

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was then created through that point and normal to the surface. An additional plane

was created that traveled through the axis and normal to x-y plane. Drawing a line in

this plane and projecting it onto the surface allowed the edge of the surface to be

used in the sketcher. Now existing on this plane was the defined edge and an axis

normal to the surface. These two items used in the sketcher allowed for the creation

of a shallow disc, baring the dimensions of the dimple, normal to the surface. This

sketch would be used to revolve cut the dimple.

Figure 13: Pro Engineer Rendering of Concept Hull

The revolve cut was made using the internal sketch above. The axis of revolution

was the normal axis created through the datum point. The remove material feature

was used to cut the dimple into the solid surface. Since a flat disc cannot be carved

into a curved surface, it was necessary to extend the geometry of the sketch beyond

the edge of the surface in order to ensure material would be removed in areas of

greater curvature.

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Patterning: First Attempt

This revolve cut then needed to be patterned along the complex surface of the hull.

To accomplish this, a curve was drawn for the pattern tool to follow. The curve was

made by projecting a straight line, drawn on the x-z plane, onto the surface. The

projected line needed to be a sketch to be used in the pattern tool. Therefore, a

plane was defined through the projection. On this newly created plane, the use edge

tool in the sketcher then made the projection into a sketch. The earlier made

revolve cut was then fill patterned along the curve created by the projection. The

results can be seen in Figure 13. Please be aware that Figure 13 does accurately

represent the size and depth of the dimple. It is only the outcome of trying to

achieve the proper results before doing so with the correct dimensions.

Fig. 14-Patterned Revolve Cut

It can be seen that the diameter and depth of the dimples does not remain constant.

This problem spawns from the patterning of the revolve cut. The initial revolve cut

was made normal to the surface. The axis of revolution for the patterned dimples

remain parallel to the original revolve cut. This means that as the surface changes

- 31 -

shape, the revolve cuts are no longer normal to the surface like the original,

resulting in dimples with inconsistent diameters and depth.

Patterning: Second Attempt

In order to create dimples of more consistent size and shape, a fill pattern was used

using an internal reference. This reference was simply a horizontal line on the x-z

plane at the eighteen foot water line. The program was then told to space the

members along a curve, i.e. follow the internal reference line, at a spacing of 1.68 ft.

This spacing was chosen because it left one diameter of space between features. By

selecting the “follow surface shape” option in the options menu and selecting the

imported surface as the reference, the program then patterned the revolve cut

along the defined line while maintaining normality on the sketching plane. This

created normalized dimples of consistent size and shape.

In order to dimple the entire vessel, this revolve cut and patterning process was to

be repeated from the eighteen foot water line to the keel. This process came to a

halt at the ninth row of dimples when one member behaved abnormally. This

particular feature was revolved as a shell, eliminating the option to remove

material. Being a patterned feature, not an original, this member was unalterable.

After changing every option available to resolve this problem with no success, this

method had to be aborted.

- 32 -

Figure 15: Dimples in Concept Hull

Patterning: Third Attempt

In a third attempt to dimple the hull of the vessel, the revolve cut was to be fill

patterned using a closed figure as an internal reference and to space the members

in the shape of a diamond. The internal reverence was simply a box enclosing the

entire surface. Again the follow surface shape option was used to maintain

normality. The members were spaced two feet apart. This successfully patterned the

revolve cut over the entire surface. Although a 1.68 foot spacing (one diameter

apart) was desired, two feet was the closest spacing that did not create errors.

To create dimples of more consistent size and shape, three pattern areas were

created; one along the x-z plane for the side of the vessel, one along the x-y plane

for the bottom of the vessel, and an additional plane intersecting the two others for

the round bilge. Overlapping features were turned off for a nearly seamless final

product.

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Figure 16: Whole Concept Hull Dimpled

Modification of this design is a simple edit definition. Turning off any unwanted

features allows for the creation of multiple pattern layouts and multiple concept

designs. The design yielding the best analysis results will be chosen for the creation

of the physical model.

Fluent

Before any fabrication is done in a production process a fundamental step must first

be completed. This step is known as analysis; according to definition, analysis is the

examination and evaluation of relevant information to obtain the best course of

action in various alternatives. An analysis is both initial and compulsory for the

creation of a prototype the MAHI mahi is no different. Within the parameters of the

M.A.H.I. mahi, analysis is done with the use of CFD (computational fluid dynamics)

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software “Fluent and Gambit.” This CFD; first designed in---- is an extremely

powerful software, industrially known simply as “Fluent,” it mathematically

simulates a body as it travels through a fluid, practically, this can be viewed as a

mathematical recreation of a wind tunnel.

Marine Advancement by Hydrodynamic starts with the development of the M.A.H.I

line. This line or boundary is the point at which the dimples are placed so as to trip

the boundary layer from laminar to turbulent. As one can infer the positioning of the

M.A.H.I line is imperative for the success of the experiment; Fluent allows us the

ability to insert an imaginary M.A.H.I. line, and then simulate the passage of the

water up to the 18 ft water line within a set control volume. “Fluent” can simulate

most fluids; based on the principle that a fluid is defined by its density. In the case of

this experiment, we simulate sea water across the hull of the vessel so we set the

fluid density as that of water 1000 g/m^3.

Processing using this software requires us first to design a control; the M.A.H.I mahi

is modeled after a 191 ft bp by 18 foot beam displacement hull vessel. There is no

need to expatiate on the modeling of the control since it was covered under the

previous chapter of this report. Never the less it is important to note that the

control to be built is in fact one tenth of the original vessel; however the model

being analyzed in “Fluent” is the being done so at its original operating length. While

the analyses will take longer it does give a better practical picture of a real life

displacement hull vessel. There was actually a large delay before this CFD could be

- 35 -

used, since there was a problem with the schools license; a lesson was quickly learnt

this software is very expensive and so, well protected by its license agreements.

However, when the software was finally up and kicking there was an immediate

question raised; one was inclined to wonder, judging from the actual name of the

software (Fluent and Gambit) where exactly does the Gambit fall in, and exactly how

it is related to the Fluent? One may also assume that since the program is commonly

referred to as Fluent, the Gambit side isn’t very important. Verily, this assumption,

while being a logical deduction, is actually a case of a logical progression being

entirely misleading and as a result iterating to an inaccurate response. With this

knowledge much time must be spent explaining the purpose of each of these

software pieces as they are used with regards to the M.A.H.I mahi.

“Gambit,” though rarely mentioned, is the software mesh; contrary to its less than

frequent mention it is in fact equally important or more important then “Fluent.”

The mesh is that piece of the program in which the mesh or control is actually

manipulated. The M.A.H.I. mahi was saved as an IGS file in Pro Surf or Pro E then

using the import command it was transferred unto “Gambit’s” operating screen. The

software supports many varying file types and like the IGS, it reads them all like a

group of coordinate, data points and then compiles them to the Gambit screen as an

image. Initially, in an attempt to transfer the image, the “read data” command was

selected from the file menu, but this method failed and so the method

aforementioned was employed. Once the image is successfully uploaded into

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“Gambit,” the true power of the software can be tested. An image must be oriented

in a particular way so as to allow proper simulation, in this case fluid is expected to

flow like as the vessel would travel in water; bow to stern. As such a left to right bow

to sturn orientation was attained by simply clicking, holding and turning the vessel in

the desired direction. The image was then seen broadside, portside with symmetry

as usual created along its longitudinal center line. A control volume is the area that

one sets for the system to analyze within, if a control volume is not set, there would

be no true area at which point analysis would start and stop this could over load the

computer, as well as make results impossibly or inaccurate. It is however important

to choose a control volume, that allows for laminar, well developed flow before the

fluid actually experiences its initial boundary condition. The CV for the M.A.H.I mahi

was set at a position of 300 feet forward and aft; this gave a total of over one

hundred feet of unaffected data before the fluid actually met the fluid- vessel

boundary. The creation of the control volume is the most important step in analysis

of the vessel, and it is also the most time consuming. The mesh area can be thought

of like an infinitely graduated Cartesian plane; as such the two initial points created

are used as reference points at (+300,0,0) and (– 300,0,0). From these points a

series of points representing the vertices of a cubed surface are created. This is

easily done, however the points running across the vessel are a challenge. If we

were required to analyze the entire vessel we would build a control volume; a cube

around the entire vessel. However the M.A.H.I line and the point of separation in

turn, can only really occur on the part of the hull that is estimated to be in the water

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at any given point in time. The 18ft vessel water mark is the highest point to which

water is expected to rise on the vessel; therefore the Gambit CV must be built so

that it only considers from keel to the 18ft waterline. One may assume that it would

make life simple if we were to draw a line from the front 300ft mark to the back –

300ft mark on the X- axis at a position of 18ft Z axis across the port side

superstructure. However the first problem started with definitions of the initial

points at (300, 0, 0) either way. To make corrections for this oversight a function

known as split line was used to create a new point at 18ft up the vertical line of the

bow. Gambit’s information tool allows for one to see the Cartesian coordinates of

points on any area on the vessel; 18ft was easy to find, and then a new point was

created as previously mentioned. The point was set on the vessel because the actual

analysis is of the vessel area itself; hence the hull must be a part of the control

volume. With this new point acquired, lines were re-drawn with the same x distance

but a different Y reference. Points located on the Z axis were placed spatially at a

distance of fourteen feet below the keel, again to allow for a well developed region.

Development of a CV is like the progression of a baby learning to walk; first the baby

learns to role, then to creep then finally and as a youngster how to walk. In gambit

we first set points and vertices as described above, then connect these points to

make lines into a cube; and last but most importantly give this cube solid faces. It is

in completing this last step that the most unique of problems arise. The broadside

area of the vessel is the reason for the entire exercise of analysis; it is the point at

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which the dimples are located and the area we would need to analyze. It is

therefore necessary to make the broadside of the vessel a face for analysis. This may

sound simple but if the model is set as it is, fluent analysis would view the broadside

of the vessel as just the face of the cube. It is hence necessary to make the

broadside of the vessel a face in the CV; this implies that where the control volume

may have been composed of the six faces of a cube it should now be increased to

seven. However, inserting a face isn’t as easy as it sounds, we must first realize that

the broadside of the vessel exists in two dimensions; both on the z and x plains,

consequently instead of the initial guess of seven faces the new CV would have eight

faces. Splitting a face is similar to splitting a line, we select the face to be split and

then using the faces icon we select the split face command. The program requires us

to split the face on two axes as previously mentioned; so once the face is split the

new CV now comprises the rounded contours of the vessel. Gambit displays the

splitting of a face, by merging the curved line following the contours of the vessel,

with the straight line representing the rest of the control volume. It is important to

note that only one side of the CV either port or starboard could be modeled at any

given time. However Gambit allows us to circumnavigate this problem, and reduce

the work load of repeating the long exercise described above, by the reflection

command. We however do not need this fantastic command because; a vessel is

symmetric along its center line, thus data analyzed on one side of the vessel is

exactly the same as that on the opposite side. As a result of the lacking computer

power available, it is important that we reduce the amount of area that the system

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must analyze. In keeping with this principle of reduction forced upon is by computer

constraints; when a face is split, an excess face is built by the line above the new,

split 18 ft waterline forward and aft as well as the top line created by the vessels

split face. To further clean the mesh therefore, this face must be deleted by

selecting the lines that make up its area, taking care not to delete what gambit

refers to as leading edges; lines that make the top of one face while making the

bottom of another. When this process is complete the remaining hull design is

displayed as half of a vessel cut along the bow and stern forward to aft along its 18

ft keel loaded waterline

Gambit command tools are set up so as to guide our thoughts through every step of

creating a control volume; hence the last step is actually creating a solid mesh.

Meshing is the actual process by which the program creates small nodules or shapes

inside the faces of the cube. The easiest shapes are simple squares but it is more

accurate to use tetrahedral, octahedral or polygon figures. The nodules further

divide the CV into smaller shapes for analyses; at every one of these shapes added in

by Gambit, Fluent analyses and calculates the required information. The more

populated the figure is with accurately defined nodules, the more precise the

calculations made by the software will be. It also goes to reason that the more

tightly spaced these nodules are, the less chance of error one will have in evaluating

the contours of the vessel. Logically though the more nodules that a present and the

greater the intricacy of the nodule designs, the longer it will take for Fluent to do its

- 40 -

analyses. Nodules are hence, generally selected to maintain high levels of accuracy,

as well as to produce the fastest result from fluent. The MAHI control volume as it is

uses tetrahedral shapes in its design, however these shapes are not graded; this

means they are all equally spaced through out. This design though highly accurate

takes a bit more time to analyze, so alternatively the CV could be graded with larger

spacing on the outer partitions and tighter spacing within the boundaries of the

vessel. To achieve this grading, and so circumvent the problem of limited computer

power, it is required that the lines created earlier be readjusted vertex by vertex.

Every time a mesh is built whether its nodes are of tetrahedral or square in nature,

or its mapping is wire meshed, paved or mapped/ paved every line must join at

some point. Node vertices are the points at which more than one of these lines

meets. It is because of this fact that grading becomes a tad bit tedious; picture one

face of the vessel that is tetrahedral and spaced at a distance of 5 cm apart for

accuracy, meeting the leading line of another area that is easier spaced with

quadrilaterals at a distance of 10 cm apart. As the name implies a vertex indicates

the meeting of lines, we must position the lines manually so as to get them as close

as possible to meeting each other at the most populated leading edge vertices. In

some cases, as in this case where there is a different nodal geometry, we are

required to adjust only the faces that can be adjusted while leaving the faces with

leading edge conflicts between tetrahedral and quadrilaterals alone.

- 41 -

When the CV is properly meshed about the vessel, the next step, as the Gambit tool

box cycle suggests, is the creation of boundary values. Boundaries are created so

that Fluent can have given parameters in which to perform its calculations. Not only

do these parameters have to be set, but it is of extreme importance that these

parameters be set at given points. To set the parameters the orientation of the

MAHI mahi must first be observed; bow to sturn orientation left to right on the

matrix. If the MAHI mahi is set at this angle the CV must thus be labeled and

parameterized with similar coordinates in mind. The left side of the CV acquires the

label of “in flow” and the boundary is set as a velocity input. Doing this lets Fluent

know that the velocity at this point is given and it needn’t derive a velocity at this

point, in essence the velocity is fixed. The right most portion of the CV is set as a

pressure outlet; here we must recall that we are testing for changes in velocity so

the outlet is one of pressure. The rest of the control volume except that defined by

the curve of the vessel, is also set as a pressure domain; since the area surrounding

the MAHI mahi is always governed by both Dynamic and Hydrostatic pressure. The

area of most importance is selected and labeled last; the contours of the vessel’s

hull. Fluent like most CFD programs considers any object set in a control volume a

wall. In other Fluent doesn’t see the vessel in its analyses as a boat but rather a wall

with dimples or without dimples. The control that is modeled initially is without

dimples, and the area, not yet defined from above, is set as its own pressure

boundary or domain. Fluent, hence still analyzes this area as a wall, but a wall with

limited to no set boundaries, we are unable to assume a boundary on the vessel’s

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hull so this pressure field command allows us to cheat by defining a member of the

CV without sufficient information. The process described above is repeated for both

the meshing of the control as well as the varying dimple design and a final meshed

surface should look similar to the following figure.

Figure 17: Fluent Screen Shot 1

N.B. only the yellow half is being considered as actually present as the CV

On completion of the Gambit mesh work an “.msh” file is created. This file is saved

and then exported into Fluent at which point the numbers connected to the analysis

are compiled and calculated. Before starting Fluent running, parameters of

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operation similar to those set up in Gambit earlier must be applied and ensured

congruent. In addition other options like initial velocity of the fluid in the control

volume and the Reynolds number of the fluid medium must also be included.

Fluent can display in many different formats, however one of the most powerful

Fluent displays is that of colour contours as illustrated in Fig# bellow the color

profile for an aerospike engine.

Figure 2: Fluent Screen Shot 2

Figure 3#: Aerospike temperature contours

Fluent uses a variation in color to articulate the changes in pressure, velocity,

Reynolds numbers and coefficient of drag in the system. A good example of color

imagery is the display given as a result of temperature changes above; the softer

colors like blues are used to represent colder temperatures while the brighter colors

like green are used to display hotter conditions. Fluent, like many other analysis

software, also uses the imagery described above to display changes in force; the

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softer colors for lower forces and colors like red for large force displacements.

D’MAHI mahi results however are displayed initially with a different sort of imagery;

Fluent requires that in the final pre-analysis processes one selects a desired number

of iterations. It is prudent that one set an initial iteration number of some relatively

small amount; so as to see how long the program takes, and if in fact the mesh is

well enough built to convergence at all. In this case the initial number is set at 100;

below is a screenshot of the graphical result.

Figure 19:Fluent Screen Shot 3

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On careful observation one can note that the graphs are in fact converging to some

point and that the mesh was well enough created. On the contrary, due to the

limited capacity of the computer, this mesh design while simple and ungraded, as

mentioned in the earlier half of this paper’s section on meshing, took a total of a

week to analyze. This is a terrible average considering that at least 10,000 iterations

are compulsory to get an acceptable result, and the more accuracy required the

more iterations needed. It is for this reason highlighted above, that mesh grading,

the time consuming procedure mentioned previously, must be done. Help must be

given to the weak computer so that it is capable of doing an analysis; it is clearly

evident under these circumstances that the system available to run this software is

the ebbing factor; and with the time frame available, though the mesh was graded it

is impossible to accomplish the ten thousand iterations required to give a different

result on each dimple variation. As a result the best guess at design must be used, so

as to complete the process in the stipulated time frame.

Fluent and Gambit is a powerful software package and with proper analysis it allows

us to ascertain the most efficient dimple design based on a decrease in the

coefficient of drag and a change in the velocity of the vessel due to this previously

mentioned coefficient. However for the program to function at its highest capacity

and so save time and effort, it must be supported by hardware with the aptitude to

correspond with its magnanimous analysis power. The MAHI mahi is a test design

based on a new principle of a dimpled hull to increased efficiency, because of CFD

- 46 -

analysis it should be possible to aspire to achieve Marine Advancement by

Hydrodynamic Input at its fullest without the tedium of physically testing all designs,

but rather the design that seems to function aptly according to CFD. It is however

important to note that the best design according to computer simulations is not

necessarily the best design in practice; “the proof of the pudding is in the eating;”

we must first test the vessel in real condition for true results regardless of the

assumptions based on the CFD software.

Construction of the Physical Model

Two seven foot physical models were to be created, a control and a concept, for

practical testing. Foam was to be machined using a CNC to create the plug that

would provide the platform to build the mold. From the mold, two parts (i.e. hulls)

would be pulled. One would remain unchanged, the control, and one would be

modified with dimples, the concept.

The Plug

The plug, also called the master, was machined form two pound density Polystyrene

foam. The surface file created in ProSurf 3 was used to create the tool path for

machining. To prevent the collar of the bit from destroying the finished surface

during machining it was necessary to prepare the foam into three inch thick layers.

To do this, we needed to use a hot wire cutter to insure that we had quality, level

- 47 -

pieces. The shop we are working in belongs to Alan Shaw, graciously donated much

of his time, knowledge, and facility to ensure construction was done correctly.

Figure 20: Makemba and Linzy Using the Hot Wire Cutter

- 48 -

Figure 21: Removing First 3 inch Section

After two three inch thick sections were prepared, the foam was ready for CNC. All machine

and labor hours were donated by Eric Rohl of Structural Composites Inc. Below are

photographs of the CNC at work.

Figure 22: CNC Machine at Structural Composites

- 49 -

Original plans called for the creation of two plugs, the control using the ProSurf 3

file, and the concept design from the Pro Engineer file. Unfortunately, the concept

design in Pro Engineer could not be machined using the three axis mill like the one at

Structural Composites Inc. It was then decided that one plug would be made to

produce one mold and two boats. One could be modified with dimples later.

After the foam was machined the layers were assembled with epoxy based resign

and hand faired. Since Polystyrene foam is a styrene based product it can not come

in contact with liquid based styrene products. This includes Polyester resigns, gel

coats, and solvents. For this reason epoxy based resign was used in direct contact

with the foam. A slurry of epoxy resign and micro balloons was applied to the

surface of the plug to protect the foam from exposure to styrene based substances.

One layer of 6 oz fiberglass sheet was followed by the epoxy and glass bubble slurry

to provide rigidity, protecting the foam from dings and dents. This process can be

seen in the images below.

- 50 -

Figure 23: Plug Coated in Epoxy Resign

Figure 24:Stern of Plug Coated in Epoxy Resign

- 51 -

After curing, any areas of overlapping fiberglass were ground smooth. The textured

surface of the fiberglass was then filled using a thick slurry of epoxy resign and micro

balloons. After fully curing, this filler coat was sanded smooth.

Figure 25: Sanding Down the Thick Spots of Epoxy Resign

A single coat of Urethane primer was applied to the surface revealing small imperfections in

the plug. High spots were then sanded down and low spots filled with Evercoat lightweight

body filler. Body work was complete when the surface was sanded smooth.

Figure 24: Applying Bondo To Plug

- 52 -

Four heavy coats of Urethane primer were sprayed on the master covering body

work and sanding scratches. To ensure the smoothest surface possible, the primer

was wet sanded with 600, 1000, and then1200 grit wet sanding paper.

Figure 27: Applying Primer and Wet Sanding Plug

The Mold

The mold, also called a tool, is the female replicate of the plug. To prevent the mold

and plug from bonding together release agents must be applied to the surface of the

plug. A minimum of three heavy coats of TR Hi-temp dry release wax were applied

and buffed off. Following wax, a minimum of six coats of PVA, Poly Vinyl Alcohol,

were applied using the gravity gun. Each coat was applied in a light mist fifteen

minutes apart.

- 53 -

Figure 28 : Applying Mold Releasing Agents

Figure 29 : Spraying on PVA

Tooling gel coat was then applied to the surface of the master. The entire gallon was

activated using 2 fl oz of MEKP, Methyl Ethyl Ketone Peroxide. Ideally the tooling gel

should be sprayed on 35 mils thick. Not having the tools required to do so, it was

rolled on instead.

- 54 -

Figure 30:Applying Tooling Gel Coat

After a few hours of curing the gel coat is hard enough to resist scratching. Although

tacky, gel coat will always remain tacky unless mixed with wax, the gel coat now

needed to be reinforced with fiberglass. Two layers of ¾ oz fiberglass matt were

saturated and rolled out with General Purpose Polyester resign. Layers of fiberglass

matt were applied two at a time at two hour intervals. After building eight layers of

matt, the mold was left to kick off over

night.

Once fully cured, the edge of the flange

was trimmed exposing the boundary

between the mold and the plug.

Wooden wedges were forced in the seam, creating space between the tool and the

Figure 31 : Trimming the Flange

- 55 -

master. After creating separation in the stern, water was forced into the mold. PVA,

being a water soluble product, dissolves into the water aiding in the release of the

mold.

Figure 32: Trying to Release the Plug from the Mold

After the water broke the suction created by the flat bottom of the mold, the plug

was removed, leaving behind a tool.

Figure 33: Pulling the Plug from the Mold

- 56 -

The Models

With the mold complete it was time to create the physical models. The tool first

needed to be cleaned. A quick wash with soap and water removed any excess PVA.

A gentle wipe with acetone removed any leftover residue.

Again, TR Hi-temp dry release wax and PVA were applied to the surface of the mold

in the same manner to prevent the models and mold from bonding together. 40 oz

of canary yellow gel coat, reduced 4:1 with styrene, was sprayed on to the mold.

After the gel coat has cured enough to resist scratching it was reinforced with

fiberglass. Again, ¾ oz

fiberglass matt was applied

two layers at a time at two

hour intervals.

After laying four layer of

matt, the model was left to

kick over night. The mold and

boat were then separated with wooden wedges and again flooded with water.

Released from the mold was the final product.

Figure 34: Fiberglass Laid in the Mold

- 57 -

Figure 35: First Part Released from Mold

The boat was place back in the mold and reinforced with two more layers of

fiberglass. Placing the boat back in the mold prevented the possibility of warping

during reinforcement. Cardboard tubes were fitted to the bottom of the boat and

fiberglass in. This provided rigidity for the sides of the vessel against hydrostatic

pressure. Unfinished edges were trimmed yielding a final product.

The second vessel was created in the exact same manner as the first. This boat

however was built with twelve layer of fiberglass matt in the stern to provide

enough thickness for modification. After the stern was properly thickened it was

modified with dimples. This was achieved by modifying the cutting edge of a half

inch drill bit. It was ground shallower to apply the dimples without cutting all the

way through the material. After cutting in the dimples more yellow gel coat was

sprayed on to yield a finished product.

The control vessel, the one left unmodified, was then air brushed with acrylic paint.

Since the acrylic paint is water soluble, it needed to be sealed with clear coat. For

- 58 -

this reason both boats were painted with clear coat to make the surface textures of

each boat was uniform, eliminating a potential source of error during testing.

Figure 36: Final Control Hull Model

- 59 -

Testing

Once the construction of our models was complete, the next step was to test our theory. After

much research we decided that a basic towing mechanism would be the best way to provide

motion to the vessels. By using a towing method, we did not have to create nor supply a

motor, power supply, and steering mechanism. We also saved ourselves the trouble of

calculating power input, output, efficiency and all other measurements needed to accurately

analyze motorized vehicles. We determined that by towing a model at a constant speed over a

given distance, we would be able to measure the force used to pull the boat across the tank.

Fluid mechanics tells us that the greater the drag force between the surface of the hull and the

water, the more force necessary to keep the vessel in motion. Therefore if we could actually

measure and record the force needed to keep the vessel moving at a constant speed, we would

be able to infer that when the force decreased, so did the drag and resistance between he hull

and the water. At this point, we set out to develop a testing facility/setup and force measuring

system.

The first step in planning our experimental testing was to locate a facility with a large enough

water tank and towing mechanism that we could have made available to us. We tried to stay as

near to our local community as possible, however the only facility meeting these standards was

Regal Marine Industries located in Orlando, Florida. Dave Catino, an employee of Regal Marine

Industries and also a Florida Institute of Technology Alumni, set up a preliminary meeting with

- 60 -

Figure 37: Test Tank Facilities at Regal Marine Industries

us at which time we toured the facilities and discussed a plan for our experiment as shown in

Figure 37. After viewing both the testing tanks and testing canal that they offered to us, we

decided that the testing tank would be the best option. The following photos will show the

testing tank that we chose to use for our experiment. Figure 38 gives an overview of the testing

tank. The testing tank was 50 feet long, 15 feet wide, and four feet deep. Since our models

were only seven feet long with a depth of one and a half feet, this was an ample size tank for

the experiment we would be running.

- 61 -

Figure 38: Actual Test Tank and Towing Beam Used for Experiment

At the very top of the photo you can see a horizontal, bright yellow beam that spreads across

the width of the test tank. Connected to this beam you can see a blue box-like piece of

equipment. The yellow beam is controlled by remote control and travels over the length of the

tank at a constant speed. The blue box houses the metal cable that is attached to a large metal

hook. This hook can be raised all the way up to the beam or lowered all the way down to the

surface of the water. Figure 39 provides a close of up the metal cable and hook mechanism.

This hook was used to attach the towing mechanism to the load cell that was attached to our

models. This set up will be discussed next.

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Figure 39 :Metal Hook for Towing Mechanism

As mentioned before, the models were going to be towed at a constant speed and we were

going to measure the force necessary to do this. In order to measure and record the force used

to pull the models, we purchased an LC-210 S-Shaped Load Cell as shown bottom left.

Figure 40: S-Type Load Cell Figure 41 : Data Logger for Load Cell

- 63 -

The bottom end of the load cell was placed over a screw we had on the bow of the model. The

top end of the load cell had a piece of metal wire tied to it and then tied to the metal hook

previously shown. On the right of the load cell you can see there is a cable attached. This cable

runs to the data logger that is shown in the photo to the right of the load cell. The data logger

actually records the readings the force gauge

is experiencing four times per second. The

numbers are then displayed on the screen.

But we needed to actually record this data on

a computer so that the data could be analyzed

in excel. So to make this happen we

purchased and R-232 to USB converter cable

(shown at right) and connected the data

logger to a laptop using the com 11 USB port.

To transfer the data from the data logger to the computer, the computer need a way to “call”

the data logger and open a pathway for the data to travel. To do this we used a program called

HyperTerminal that comes standard on

modern computers. Once the data

logger and laptop are synced, you just

start at stop the transfer using the

respective commands on

HyperTerminal for each trial. The data

Figure 42: R-232 to USB Cable

Figure 43- HyperTerminal Screen Shot

- 64 -

for each trial is collected in a text file that can then be transported in Excel. From there we

would be able to graph the results and provide graphical representation of the forces

experienced by the load cell over the length of the tank.

The photograph below shows all the parts of the experiment put together. You can see the

metal hook lowered to the water, the load cell on the bow of the boat attached to the metal

hook, and the laptop and data logger off to the side of the tank. Something else that you see in

this picture is bags inside the model. These grocery bags were each filled with sand to sink the

boat down to the eighteen foot water line. By the time this process was complete, the boats

weighed 135 pounds. Now that all of the set up was completed, it was time to actually run the

experiment.

Figure 44: Model and Towing Mechanism Set Up

- 65 -

To begin the experimentation, we first had to calculate the constant speed at which the towing

mechanism was moving. To do this we simply measured the time it took for the hook to travel

a given distance. We chose a 16 foot long section in the center of the towing tank as our given

distance. This way the beam had already reached its maximum constant speed and was not

beginning to decrease in speed either. Using a stop watch, we clocked the metal hook traveling

this distance and measured a time of 35.2 seconds. Using a simple distance divided by time

equation, we calculated that the speed of the beam was 2.2 feet per second. However, we had

intended to tow the model at the maximum velocity for a displacement hull which is 1.34 x

loaded water line. Using this calculation we determined that the ideal towing speed would be

5.9 feet per second. But since this value is the maximum velocity at which a displacement hull

can travel, then it the actual towing speed of 2.2 feet per second still falls in the range of

accurate traveling speeds for a displacement hull.

Next, we were ready to run a test trial to make sure that load cell was read properly and the

data logger and HyperTerminal were properly synced and recording. Once everything was

calibrated, we were ready to begin.

Due to the block of time allotted to us to complete our testing, we were only able to complete

ten trials for each model, resulting in twenty data sets. First we ran the experiments with the

control model. The tests did not run quite as smoothly as we had intended. Since the hook up

between the models and the towing mechanism was not rigid, the models were a little hard to

control after the each trial. The models picked up so much speed and momentum, that they

actually got ahead of the hook and snapped the wire a few times. Luckily, the problems

- 66 -

occurred after the period of the tests where the section of data being analyzed was actually

recorded. We continued to observe and record each trial and accumulated enough data to

create and compare graphical representations. For example, look at two randomly selected

graphs from the control model experiments. Figure ___ is from the first trial run using the

control model. Unfortunately, we did not ever achieve a constant velocity during the test

which would be shown as a linearly across time interval. This is what we had hoped to achieve

from our testing methods. As we continued to graph the rest of the data, we continued to view

the same trend. Figure ---- shows is from the third trial run using the control model and

shows the same general pattern and Figure____. But since the towing method and facilities did

not allow the models to ever reach a constant velocity, we were forced to analyze the data we

did obtain.

Figure 45 :Trial 1 Data from Control Hull Model Test

Force- lbf

Time-sec

- 67 -

Figure 46 :Trial 3 Data from Control Hull Model Test

The first spike that you see in the graphs is portion of data that we are analyzing. The portion

of the spike with the increasing slope is actually showing the vessel as it slowly beings to move

and the force is increasing. The maximum at the top of the spike shows the maximum amount

of force necessary to bring the vessel up to speed. The decreasing slope portion of the spike

shows the vessel catching up to the hook and maintaining its own motion speed, therefore

decreasing the force need to keep the vessel moving. All the other data past the point where

the spike ends is data after the model reached the end of the tank. As we observed the waters

behavior around the point of separation and the stern of the vessel, we did not observe

anything out of the ordinary. In fact, the water behaved the same as shown in Figure 4 found in

the Background section of this report.

Force- lbf

Time-sec

- 68 -

For testing our concept hull all the same procedures were followed. Ten trials were completed

and the data was analyzed using graphs in Excel. Again, let’s examine two randomly selected

trials from the concept hull tests. The first graph shows the same general pattern as shown for

the control model data. There is the spike in the beginning of the graph that we will be

examining. All the other data past the point where the spike ends is data after the model

reached the end of the tank. But if you look at this graph compared to the previous graphs, you

will notice that the maximum force value of the spike is only 5.71 lbf. The maximum values

from the first two graphs were 10.66 lbf and 9.05 lbf respectively. Now look at the second

graph for the concept hull data, Figure ___.

Figure 47: Trial 3 Data from Concept Hull Model Test

Force- lbf

Time-sec

- 69 -

Figure 48: Trial 10 Data from Concept Hull Model Test

Again, look at the maximum force experienced in this trial. It is only 6.78 lbf. Just be these

observations, we began to believe that our theory may be correct. We continued to further

analyze our results and took the average maximum forces experienced by each hull. For the

control hull model, the maximum force was 8.44 lbf. For the concept hull model, the maximum

force was 7.76 lbf. These values support our theory that our concept hull reduced drag and

resistance created between the surface of the hull and the water. Unfortunately, we did not

feel that the amount of data we have collected at that point, nor the quality, is sufficient

enough to draw a strong conclusion and deem our theory correct. However, we did believe

that this data does suggest that our theory may be correct. It is for this reason that we hope to

continue working on better testing facilities and methods so can gather significant data and

draw an accurate conclusion. The raw data and graphs for each trail can be found in the

appendix.

Force- lbf

Time-sec

- 70 -

Although the numerical data can only suggest that our theory may be correct, we do have visual data of

our observations to further support our allegations. As mentioned before, the wake of the control hull

model behaved in the same manner as expected. The point of separation was between amiship and the

stern, and the wake formed the pattern previously discussed in the history portion of this paper. The

following photos show exactly

this.

Normal Wake Pattern

Figure 49 : Photo Capture 1 from Control Model

Test Video

- 71 -

However, the really interesting visual proof comes from the screen captures of the concept hull

test videos. When we examined the videos, we noticed a very concentrated stream of water

flowing off the point of the stern as opposed to the open wake patterns observed with the

control model. You could actually see the water get sucked back in against the hull and stay

attached to until the last point on the hull. This means that you can actually see the dimples

reattach the flow which is the main goal of this project. The following photos will provide visual

explanations.

Normal Wake Pattern

Figure 50: Photo Capture 2 from Control Model

Test Video

- 72 -

Now, as you look at the above photo, you can see the concentrated stream of water. Notice

how the stream of water generates from the rear most point of the stern of the concept vessel.

This shows that the water is not detaching from the surface of the hull as it travels over the

stern. It is not detaching until there is no longer any hull surface to travel across.

Concentrated Stream of Water

Figure 51 : Photo Capture 1 from Concept Model

Test Video

- 73 -

Figure ____takes this to the next step. First, notice again that you can see a very pronounced,

concentrated stream of water leaving the rear most point of the vessel. Recall in the control

model photos how you could see the wake leaving the stern of the vessel. In this figure you can

see that there is not any wake coming off the stern of the vessel. In fact, the water is

completely smooth around the stern. As previously discussed in the background portion of this

paper, there are two points on a displacement hull where the water separates and wake is

created: the bow, and past amidship near the stern. This is shown in Figure 4. So how did the

wake from the stern disappear? The following photo will show how this happened.

Concentrated Stream of Water

Figure 52: Photo Capture 2 from Concept Model

Test Video

Notice there is no wake coming off

this portion of the vessel as there was

on the control hull.

- 74 -

Again, in this photo notice the same characteristics of the water previously discussed. But this

photo points out the next observation in this process. In this photo you can actually see curved

flow of water behind the standard point of separation you would find on our control model.

Also notice that there isn’t any wake detaching from the hull in this area. In fact, if you look

closely you can see that the wake you’re observing does not generate from the rear portion of

the hull shown. The curvature of the wake near the bottom right corner of the photo suggests

that the wake generate much further forward from the vessel, possible even the bow.

Therefore, if there is no wake being generated form the rear of the hull, you can see a curved

area around the stern that appears to be the water reattaching to the hull, and there is a

Concentrated Flow of Water

Area where water is being reattached

to the surface of the hull.

Point of Separation

Figure 53 : Photo Capture 3 from Concept Model

Test Video

- 75 -

concentrated stream of water leaving the rear most point of the vessel, then we can conclude

that the water being displaced around the stern is being reattached due to the dimples on the

surface of the hull in the examined area. This means that our theory is correct, and dimples on

the stern of a displacement hull will in fact reattach the flow.

Although we are not drawing the basis of our conclusion form the numerical data because we

know it is not mathematically sound, there is still error that should be considered for the testing

portion of this project. First and most importantly, the models never reached a period of

constant velocity where we could compare linear data. This systematic error in measurement

was the greatest source of error, and is the main reason that we want to find a new testing

facility where this can be eliminated. Another systematic source of error in measurement is

the way the towing mechanism was attached to the load cell. We chose metal wire because we

believed it would have the least amount of elasticity and elongation when a force was applied

to it. However, we did not measure if there was in fact and elasticity or elongation in the wire

when a force was applied to it. This may have slightly altered the force reading on the load cell.

Also, since neither the load cell nor metal hook were rigidly attached, the hook and load cell

were able to swivel and turn which again may have caused discrepancies in the readings from

the load cell. The load cell and data logger also provided intrinsic systematic error. The

uncertainty in measurement in the load cell and data logger was 0.01 lbf. Since the all the

data logging was measured and recorded electronically, there was not a great source of random

human error in this experiment. We can also compute the standard deviation of the maximum

forces experienced in each trial and the averages that we calculated. The average maximum

- 76 -

force experienced in the control hull tests was 8.44 lbf with a standard deviation of 1.99 lbf.

The average maximum force experienced in concept hull tests was 7.77 lbf with a standard

deviation of 2.19 lbf. From this point we were able to calculate the percent error in each trial

by using % ox = (ox / x ) 100% [A3]. The percent error in the control hull experiment was

(1.99/8.44)100% = 23.58% error. The percent error in the concept hull experiment was

(2.19/7.77)100% = 28.19% error. These values fall very close to each other which suggest that

there was the same amount of error in each trial. This is important to know because if one trial

had a much larger source of error than the other, then we would not be able to compare the

results. Overall the percent error could be smaller, but considering all the sources of error in

the testing method we think that this is definitely an acceptable value. So overall, we do feel

that this experiment has been successful even though the numerical data should be deemed

inconclusive.

- 77 -

Budget

Total 3800.00

Spent 3793.17

Remaining 6.83

Expense Report

Purchases Quantity Price each Amount

5 gal. Hexion 6735 G.P. Resign 9 109.67 987.03

QT. MEKP Catalyst 2 11.41 22.82

1 11.00 11.00

6OZ-30" Fabric 100 3.63 363.00

3/4OZ-50" Mat 20 3.23 64.60

91 1.94 176.54

Gal PVA#10 Film 1 14.87 14.87

Gal YA541 Canary Yellow Gel Coat 4 47.73 190.92 Gal CCP 945-B-201 Cooks Black Tooling Gel 4 61.66 246.64

Can 14OZ TR-104 Hi-Temp Past Wax 1 13.06 13.06

Jump Dirve 1 78.87 78.87

Foam 8'x32"x42" 1 460.00 460.00

Fuel Reimbersment 1 74.90 74.90

Acetone 5gal 1 49.86 49.86

1gal Styrene 1 19.20 19.20

Box L latex gloves 1 7.89 7.89

Slv 5QT measuring container 1 44.50 44.50

Stir Stix 1 4.16 4.16

3" brushes 1 17.89 17.89

3/4"x3" alum roller 3 7.42 22.26

Box 80 grit 1 12.85 12.85

Box 120 grit 1 11.12 11.12

Block sander 2 5.77 11.54

2.5 Gravity gun 1 85.95 85.95

12" scissors 1 39.12 39.12

9" roller 3 1.88 5.64

9" roller frame 3 2.23 6.69

3" trim roller 3 1.60 4.80

Paint strainer 50 0.07 3.50

3 gal epoxy resign kit 1 123.85 123.85

gal 3M micro bubbles 1 15.00 15.00

5" med spreaders 10 0.31 3.10

Force gage 1 400.00 400.00

Small Purchases 1 100.00 100.00

Printing and binding 1 100.00 100.00

Total 3793.17

- 78 -

Safety and Precautions

In constructing the physical models, we came in contact with many composite

materials. With each item there was some amount of risk involved. Each member of

our team accepted these risks and agreed to take all steps necessary to prevent any

undesirable situations.

Unsaturated Polyester Resin

Unsaturated Polyester Resin was used frequently throughout this project. This resin

is a light straw colored solution with a styrene odor. To protect our eyes, safety

glasses should be worn whenever using this product. If the resin gets into the eyes it

can cause severe irritation including tearing, redness and blurred vision. In the event

of eye exposure, eyes should be flushed with lukewarm water for at least 15 minutes

and medical attention should be obtained.

To protect skin from overexposure, latex gloves, long sleeved clothing, and closed

toe shoes should be worn. This product can cause moderate irritation, defatting,

dermatitis, and sensitization with prolonged exposure to the skin. If contact with the

skin occurs, the area should be thoroughly washed with soap and water. If it comes

in contact with clothing, affected pieces of clothing should be removed as soon as

possible, making sure to wash it before wearing it again.

Air purifying respirators should be worn at all times when using this product to

protect our lungs from organic vapors. All members of our group, who are able,

were respirator certified. Avoid breathing the vapor or mist that may be produced

- 79 -

when pouring this material. Excessive inhalation can cause nasal and respiratory

irritation, dizziness, weakness, nausea, fatigue, and headaches. High concentrations

may cause central nervous system depression. If an individual begins to feel the

effect of this chemical, that person should be removed to fresh air. Also seek

medical attention for prolonged exposure. Always work in a very well ventilated area

in order to keep the airborne vapor concentrations below the limit specified in the

MSDS sheet.

In the event of ingestion, the victim should be kept calm and warm. Vomiting should

not be induced because aspiration of the chemical into the lungs can cause chemical

pneumonitis, which can become fatal. If this product is continually ingested it can

cause gastrointestinal irritation, nausea, vomiting, and diarrhea. To prevent

individuals from trying to eat the resin, our group was advised that eating the resin

can be fatal.

Unsaturated Polyester Resin should be stored away from sources of heat, electrical

equipment, sparks, and open flame. If exposed to extreme heat closed containers

could explode. In the event of a fire, foam, carbon dioxide, or chemical fire fighting

should be used. Under normal conditions this chemical is stable. We should avoid

contact with strong mineral acids, peroxides, and polymerization catalysts, unless

we are mixing them in specific amounts to use for the construction of the boat.

Thermal decomposition of this product may release carbon dioxide and/or carbon

monoxide.

- 80 -

In the event of a spill, all sources of ignition should be removed and the area should

be ventilated. The spill should be contained and then covered with an inert

absorbent material and shoveled with a non-sparking tool into a container. The

waste material should be disposed of in accordance with federal, state, and local

regulations.

NOROX MEKP-925

NOROX MEKP-925 produced by Norac, Inc. was the catalyst used for the polyester

resign. This product is a methyl ethyl ketone peroxide (MEKP). It is in the organic

peroxide-ketone peroxide family. The catalyst is a watery white liquid with a slight

odor.

Just like with the resin, safety glasses should be worn to protect our eyes. Contact

with the eyes can cause severe corrosion or even blindness. In the case of contact

with the eyes, the person should remove their contacts immediately, and proceed to

flush their eyes with water for at least 15 minutes, making sure to flush under their

eyelids. Also seek medical attention.

Long sleeved loose clothing should be worn when working with the resin and

catalyst. In the case of the catalyst contacting the skin or clothing, the affected

clothing should be removed immediately. The affected skin should be washed with

soap and a large amount of water for at least 15 minutes. If irritation or adverse

symptoms develop, the person should seek medical attention.

- 81 -

This catalyst is moderately toxic by inhalation. Prolonged inhalation of vapors can

cause mucous membrane irritation and vertigo. In order to prevent a situation like

this, respirators should be worn to protect against organic vapors. If a group

member begins to feel the effects of the chemical, they should be moved to an area

with fresh air. If their breathing becomes labored or they are coughing, they develop

irritation or other symptoms, they should immediately seek medical attention. They

should seek medical attention even if the symptoms arise a few hours after the

initial exposure.

In the case of ingestion this chemical is particularly damaging. It can cause changes

in the structure or function of the esophagus, nausea, vomiting, and other

gastrointestinal effects. If someone ingests the catalyst, vomiting should not be

induced. The victim should drink plenty of water and contact the poison control

center along with a physician for medical attention.

MEKP should be stored above 80F for longer shelf life and stability. Storage in

temperatures over 100F can lead to degassing and potential container rupture. All

unmixed material remaining at the end of the day should be stored in a proper

organic peroxide container and not returned to the original container. In the case of

a spill, the catalyst should be contained, absorbed with an inert material and

scooped into a polyehtylene container. It should not be put in a steel container as

decomposition may occur. This product should not be allowed to enter drains,

sewers, or streams.

- 82 -

PARTALL Film#10

This product is a Polyvinyl Alcohol (PVA) release coating. PVA is a liquid that is clear

green in appearance and has an odor similar to rubbing alcohol.

To prevent this product from contacting eyes, only the person spraying the product

should be in the room. The person spraying should also be wearing safety glasses to

prevent any of the mist from getting into their own eyes. If contact with eyes occurs,

eyes should be flushed with cold water for 15 minutes and seek medical attention.

Repeated exposure to this product can cause conjunctiva.

The PVA may cause skin irritation. Repeated exposure can cause defatting and skin

dermatitis. To avoid this, gloves should be worn when handling the product. If

contact with clothing occurs, contaminated items should be removed immediately.

Contaminated articles should be washed before wearing again. If the irritation

persists, seek medical attention.

To prevent inhalation, an air purifying respirator should be worn when using this

product. Repeated exposure to PVA by inhalation may cause central nervous system

depression, including headaches, dizziness, loss of coordination and

unconsciousness. If individuals become lightheaded or has trouble breathing, they

should be moved to a more ventilated area, like outside so that they can breathe

fresh air. If their breathing stops, immediately seek medical attention via 911, and

notify someone who knows CPR.

If ingested, it can cause nausea, vomiting, gastrointestinal bleeding, abdominal pain,

and central nervous system depression. The symptoms of central nervous system

- 83 -

depression can range from drunkenness to unconsciousness, narcosis, coma,

respiratory failure, and death, depending on the amount of product ingested. If

ingestion occurs, victims should immediately seek medical attention. Vomiting

should not be induced unless directed to by medical personnel. If the person begins

to vomit, their head should be kept below their hips to avoid aspiration into the

lungs. We will not leave the person unattended.

PVA should be stored in a cool dry place below 100F away from open flames, heat

and sparks. The work area should be kept free of any hot metal surfaces and other

sources of ignition due to the products low flash point. In the case of a spill, the spill

should be stopped at the source first and the mess cleaned second. The floor can

become very slippery when wet after a spill where there is residual material still on

the floor. This product will not cause damage to the environment because it is

inherently biodegradable and completely water soluble.

Coating Gelcoat Series 945

Series 945 gelcoat is a polyester tooling gelcoat formulated to be used in composites

and fiberglass products. Safety glasses should be worn when using the gelcoat to

avoid any contact with our eyes. This can cause burns to the eyes. Extended

exposure can cause irritation, tearing, redness, and discomfort. If gelcoat makes

contact with eyes, the eyes should be rinsed immediately with plenty of water for at

least 15 minutes. Eyes should also be kept open and a medical professional should

be contacted if exposure to the eyes occurs.

- 84 -

This product can be an irritant on the skin and can also be slightly absorbed by skin.

Latex gloves should be worn to protect our hands from any splashes. If contact with

skin occurs, skin should be washed with soap and water, and any clothing that has

become contaminated should be removed. If any irritation occurs, consult a doctor.

Extended exposure can cause irritation and defatting that can lead to dermatitis.

While applying this product a respirator must be worn. If an individual becomes

affected by the fumes, they should be escorted outside to fresh air. In the event they

pass out or lose consciousness, call 911.

If ingested, vomiting should not be induced. Ingesting this product can cause mouth

throat, esophagus, and stomach irritation, nausea, vomiting and diarrhea.

Always work in a well ventilated area. This product needs to be kept away from

static charges, open flame, and sparks. There is a chance of ignition if kept around

these conditions. Keep this product away from heat, electrical equipment, welding

equipment, and cutting torches because this product can ignite explosively. The

tooling gelcoat should not be stored above 100F, and the containers should be kept

closed when not in use to prevent spills. This product should be disposed of as

hazardous waste in accordance with environmental regulations.

Coating Gelcoat Series 944

The Series 944 gelcoat will be used to create a hard colored exterior for our boat

models. This is a polyester coating formulated to be used with composite and

fiberglass materials.

- 85 -

The same safety precautions should be followed for the series 944 gelcoat as the

series 945 gelcoat. When cutting or drilling gelcoat, respirators should be worn to

protect from dust inhalation. Repeated exposure to dust can cause delayed lung

injury and is a cancer hazard, but a single exposure will not result in serious adverse

reactions.

Epoxy Resin

Epoxy resin is a semi yellow liquid with a mild odor. To protect our eyes when

applying this resin, safety glasses should be worn. If contact with eyes occurs, eyes

should be flushed thoroughly with water for several minutes. If any irritation

continues contact an ophthalmologist. Exposure can cause slight temporary eye

irritation, but corneal injury is unlikely.

To protect our skin, gloves, loose clothing, and closed toes shoes should be worn

while applying the resin. In the case of contact with skin, wash the affected area

with water. Remove and wash any contaminated articles of clothing. This resin has

been known to cause allergic reactions in some people. Prolonged exposure is not

likely to cause significant skin irritation, but some redness may occur.

This resin has no significant reactions if swallowed in a small amount and therefore

no medical attention will be necessary per the MSDS sheet. It is still recommended

that ingestion be avoided.

When using this product, like the other resin and gelcoats, respirators must be worn.

This product does not release any significant vapors, although if an individual begins

to feel effected by the vapors they should be moved to fresh air.

- 86 -

This product can not enter any soil, ditches, sewers and waterways. It should be

disposed of as hazardous waist in accordance to environmental regulations. It

should also be stored away from open flames as it could cause an explosion.

Acetone

Acetone is a colorless liquid with a sweet pungent odor. To avoid any splashes into

our eyes safety glasses should be worn while handling this product. If contact with

eyes occurs, eyes should be flushed with water for 15 minutes and then consult a

doctor.

This product can cause skin irritation after prolonged exposure. To avoid any type of

skin irritation, gloves should be worn while working with the acetone. If skin

irritation occurs, wash irritated area with fresh water thoroughly. If clothing

becomes contaminated with acetone, articles should be removed and washed

before wearing them again.

There is a strong odor associated with this product. Inhaling excessive amounts of

these vapors can cause drowsiness, dizziness, nausea, headaches, paralysis, loss of

consciousness or even death. Only work with this product in a well ventilated area

and in very small quantities. Again, respirators must be worn when working with this

product.

Acetone can be harmful or fatal if swallowed. It can affect the central nervous

system, cause coma or even death. If ingestion occurs, the victim should not vomit.

Contact the poison control center immediately.

- 87 -

Acetone should be stored in a cool dry place away from any sparks, heat or flames.

Results

At this point in the project, we have not completed the computer analysis or the

field testing. For this reason we do not have any results.

Discussion

At this point in the project, we do not have results from the computer analysis or

the field testing. However, do have implications about the project. The roper

creation of the MAHI line leading to the fabrication of the MAHI mahi should

essentially lead to the production of a more efficient displacement hull vessel.

Predicted functioning of this experiment would reduce the coefficient of drag on the

hull by allowing for proper reattachment of the flow as it travels along the vessel.

As is mentioned in the Naval Architecture portion of the report, a displacement hull

is limited in speed to no faster than the square root of its waterline length. This

implies, that the MAHI mahi wouldn’t travel considerably faster; but based on the

tow rope test, as described previously, the vessel should in fact travel faster in a

given area, relative to the speed control. If the MAHI mahi arrives first over a given

distance then we calculate the speed, and we assume that the reason for this is the

MAHI line; since this should be the largest manipulated variable.

- 88 -

Though there would be no massive increase in the speed of the vessel, it should be

recalled that increasing speed generally on a displacement hull uses huge amounts

of fuel to no avail while causing cavitation and excess vibration. Fuel costs have

been sky rocketing in recent times, so an increase in efficiency formed by inserting

the MAHI line should be of great value.

The logistics of mass implementation of MAHI technology may prove a stumbling

block for the success of this invention; since the cost of re-fabricating the entire hull

of older vessels by far outweigh the benefits of efficiency and reduced fuel

consumption. However if the MAHI mahi is a success further research can go into

creating the same effect by the addition of a skin to the hull of a displacement

vessels. This dimpled skin can be added to the hull of older vessel while the newer

vessels can be designed with the MAHI line already involved. This technique

provides both for the short term and the long term, older vessels can benefit,

perhaps not as well but with some better efficiency until they go in for overhaul

where they can be re-fabricated.

Conclusion

At this time we can only draw qualitative conclusions from our visual results as

discussed in the testing and results portion of this report.

Recommendations

We would recommend a few changes for the testing methods of our two boat hulls.

We would first like to recommend using an actual towing tank, but with the nearest

- 89 -

facility being in Maryland, this may not be feasible. We discovered during testing at

Regal Marine Industries, that a 50 foot long tank did not allow our boats to get up to

a constant speed. In order to get conclusive results we would need a much longer

tank, probably at least 3 times as long as the one we used. There needs to be

enough room for the boats to accelerate, reach a constant speed, and then move

through the tank at the constant speed for a long enough period of time to collect

data. We would also recommend researching alternative testing methods such as a

wind tunnel or towing from a boat.

- 90 -

References

Figure 1: <www.see.ed.ac.uk/.../fluids14/separation.html>

Figure 2: <www.iayork.com/Images/8-2-07/wake.jpg>

Golf Balls

<http://www.golfeurope.com/almanac/history/golf_ball.htm> (incl. pictures).

Displacement Hulls-

<http://www.deere.com/en_US/rg/infocenter/marketapplications/marine/hull_types/index

.html>.

photo- <http://news.bbc.co.uk/olmedia/720000/images/_724753_tanker300.jpg>

Dr. Sainsbury class handouts.

Book 1- Ship Model Testing, Phillips-Birt, 1970.

Book 2- Introduction to Naval Architecure, Thomas C. Gillmer and Bruce Johnson, United

States Naval Institute, 1982.

Hollister, Stephen M. “The Dirty Little Secrets of Hull Design by Computer.” Apr. 24, 2008. <http://www.newavesys.com/secrets.htm>.

- 91 -

Appendices

Timeline

February:

Week 1 (4th)

Complete Rough budget, Draft of Brochure, Abstract, Proposal, Progress ppt.

Preliminary Control Design Completed, Begin test designs Improved Brochure

First assignments of Report completed, new assignments made. Have read Pro E and Fluent Tutorials

Week 2 (11th)

Begin Learning Pro and Fluent this week

Continue research of fluid mechanics and displacement hulls

Final Brochure Completed

Write up of Testing Methods (equip, time, location…)

Start BOM for Preliminary Design Review

Work on test designs in Pro E

2nd assignment of report completed

Week 3 (18th)

BOM Presentation

Create specified materials list

Adjust Budget

Continue working with Fluent and Pro E

Week 4 (25th)

Start Fluent Analysis on Control Model

Work on write up of Fluent Analysis right away so its fresh

Work on Pro E hull modifications (Finish by end of spring break)

Make list of environmental, health, and safety issues and how to address each

3rd Report Assignments due

Start funding proposals

March:

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Week 5 (3rd ) --- Spring Break

Work on report assignments and continue fluent analysis

Work on funding proposals

Week 6 (10th )

Finish safety list

Begin Fluent Analysis on test hulls

Contact possible companies to make plugs

Finish Funding Proposals, send out

Week 7 (17th)

Safety List Due on the 19th

Finalize Budget & Materials List

Final report assignment complete

Stay in contact with vector works

Week 8 (24th)

Finish Report on Optimizing Design

Make all finalizations on designs

Continue writing up all Fluent analysis

Create Shopping plan for materials

Get all paperwork ready for purchasing materials

Follow up with funding proposals

Week 9 (31st)

Develop a plan to control quality of design and testing

Purchase Materials

ELABORATE REPORT

April

Week 10 (7th)

Finish purchasing materials

Being final presentation and paper

Week 11 (14th)

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Arrange to use all materials for testing

Make sure all paperwork is up to date

Finish final presentation and present

Continue working on companies to make plugs

Week 12 (21st)

REPORT DUE

Continue working on computer modeling

Begin naval architecture calculations

Week 13 (28th)

Study for Finals!

May

Week 14 (5th)

FINALS WEEK

Week 15 (12th)

Finish all Fluent Analysis

Try to finish Pro E models

Continue working on naval architecture calculations

Week 16 (19th)

Continue working on Pro-E Models

Set date with BCC to do testing

Finish Pro-E models

Finish Fluent Models

Finish naval architecture calculations

Week 17 (26th)

Get foam plugs made or at least scheduled

Build testing equipment

June

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Week 18 (2nd)

Analyze results

Continue working on report

CRUISE

Week 19 (9th)

Test Models

Work on write up of building models and testing

Continue working on report

Start presentation poster

Work on cruise reports

Week 20 (16th)

Analyze results

Create graphs of results

Finish up all mathematical analysis

Work on final report

Start planning final presentation

Start finalizing presentation poster

Week 21 (23rd)

Finalize Report

Finish Presentation Poster

Week 22 (30th)

Finalize Report

Get presentation poster printed

Finalize Design notebook

July

Week 23 (7th)

Review and prepare for final presentation

Continue perfecting report

Week 24 (14th)

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Finish Paper

Relax and prepare for presentation

Week 25 (21st)

PRACTICE PRACTICE PRACTICE PRESENTATION

FINAL PRESENTATION

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Apt. 304

151 Eber Rd.

Melbourne FL, 32901

Phone (772) 418-7063

E-mail kdonnell@fit.edu

Kevin Donnelly

Objective To acquire as much hands on experience with the marine industry as possible.

Work experience Dec 2001 - Present Happy Times Charters Stuart, FL

1st Mate/Deck Hand

Jan 2002 – July 2005 West Marine Jensen Beach, FL

Part time sales associate

May 2003 – Sep 2004 North Side Marina Stuart, FL

Dock Master

Aug 2005 – Present Island Boat Lines Merit Island, FL

Captain

Aug 2005 - Present Indian River Queen Cocoa, FL

Deck Hand/Crew

Aug 2006 - Present Centerfold Sport Fishing Charters Port Canaveral, FL

Captain/1st Mate

Education Expected Bachelors degree in Ocean Engineering, Florida Institute of

Technology (2009)

Accreditations and

licenses

50 ton master captains license

First aid certification

Adult and child CPR certification

Marine Radio Operators Permit (MROP)

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Andrea McAllister

Objective

Education

To obtain an internship to further my knowledge of the Ocean Engineering

profession

2004-Present Florida Institute of Technology Melbourne, FL

Bachelor of Science, Ocean Engineering major

Expected graduation December 2009

Member of Phi Eta Sigma (Freshman Honor Society)

Relevant Courses

Experience

Engineering Materials Statics and Dynamics

Physical Oceanography Digital Logic

Software/Hardware Design

Wave Theory

Protection of Marine Materials

Fundamentals of Naval

Architecture

April 2008 Florida Institute of Technology Melbourne, FL

Technology Support Center Phone Tech

Provided Technology Support to the campus community via phone

Fall 2005 Florida Institute of Technology Melbourne, FL

Student Assistant

Answered student and visitor questions about various Student Life activities

Maintained orderliness of Student Union Building

Enforced facility policies

Summer 2005 Diamond Diabetic Products Pinellas Park, FL

Office Assistant

Scanned and copied documents to improve record keeping process

Verified business address and phone numbers using Internet Explorer

Skills

Basic computer knowledge

Microsoft Excel, PowerPoint, Word

150 West University Blvd

FIT Box #5681

Melbourne, FL 32901

(727) 432-7223

amcallis@fit.edu

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