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Problem Statement As High School students, we have not fully investigated or applied the concepts and applications of electronics, fluid dynamics, energy systems, mechanical systems, calculus and physics in the construction and use of submersible technologies
Entirely math, physics, and engineering based Challenging to make all components work in unison Realistic goal, and submersibles have a place in the modern world
Group Development Randy – Leader due to personal
experiences and strong will for the completion of the project
Grant – Scribe due to neat hand writing and attention to detail
David – Time Keeper due to his past experiences with engineering and his ability to accurately a lot time for each task
Background First submarine made by Dutch. Used oars underwater for
propulsion First military submarine was produced by an American
Nicknamed Turtle Failed during trial run in the civil war Consequently submarine projects were abandoned until the 20th
century
Modified with internal combustion engines, newer ballast control systems, silent propulsion systems, a nuclear missiles
Customer Mr. Pritchard – ITC instructor and will serve as our
supervisor Ms. Brandner – AP Calculus BC instructor and will serve as
our mathematical and physics expert
Project Scope Research, design and build submersible Deliverables:
Submarine Final Report Final PowerPoint Presentation
Consult Experts: Teachers Hobby Experts Hardware Experts
Less than $400
Research• How does a submarine work?• What materials are submersibles made out of?• How do RC components work underwater?• Ballast Systems• Hull Design• Propulsion Systems
Free Force Body Diagram The force of weight is combating the
force of buoyancy Recall as the volume of the object
decreases, so does the buoyant force This allows the force of weight to take a
more pronounced effect in bringing the submarine down underwater
When the volume increases, buoyancy becomes stronger, forcing the object towards the surface
Hull Design Wet vs. Dry Hull PVC is optimal because it
is a polymer / composite with a density near 1 and rather strong
Propulsion Propellers attached to waterproof
motor Ranking characteristics for power
Angular frequency Slant length Length of blade Number of blades
RC Components Water disrupts radio waves AM frequency will go down to 20 feet
good reception FM frequency stops at 5 feet RC frequencies stop around 4 feet
underwater Possibility of extending the receiver
wire to the surface in tether cord
Criteria Must function underwater Waterproof Electronic components are protected (safety) Movement with 3 degrees of Freedom Ballast System Maintain Neutral Buoyancy [still and motion] Diving range 5-10 ft. Video Feed (optional) Lighting (optional)
Constraints Limited weight due to
buoyancy Limited Budgets ($400) Materials must withstand
underwater pressure All materials must run off
the same power source with the voltage drop
Depth is limited to tether line
Select an approach
Criteria Design 1 (Randy) Design 2 (Grant) Design 3 (David)
3 degrees of freedom
4 3 4
Waterproof 3 5 3
Camera Feed 5 3 3
Functional (underwater)
1 1 1
Diving range below 4 ft.
1 1 1
Electronics protected
Y Y Y
Total 14 13 12
Initial Design Saddle Ballast Tank Design
Wanted to keep ballast tanks away from the center hull to keep electronics dry
Middle tube is dry 2 outside tubes are the ballast
tanks Gas powered ballast
Solenoid Valves release air
Mathematical Based Design The ballast tanks must be large enough to
change the volume of water displaced to the point that the submarine will sink
Based on our list of materials, and Randy’s design, the mass is estimated to be around 36 pounds or 16.329 kilograms
The center hull must be four inches with an access port in the middle for electronics, and ballast must be adjusted accordingly
Mathematical Based Design 16.329 kilograms Assuming a 16.329 kilogram mass, the
volume must be around 16.329 liters to be neutrally buoyant (density = 1)
Volume of center hull 7.492 L Volume of access port .227 L Volume of motors .140 L Volume of solenoid boxes .442 L Total Volume without ballast tanks is 8.301 L
Mathematical Based Design Total Volume for neutral buoyancy must be 16.329 L Total Volume without ballast tanks is 8.301 L
Total Volume assuming 4” diameter ballast tanks is 23.285 L Total Volume assuming 6” diameter ballast tanks is 41.968 L Volume of air in both dust off containers is 8.000 L Percentage of ballast tank used assuming 4” ballast is
approximately 46% to sink = 8.091 L of air space Percentage of ballast tank used assuming 6” ballast is
approximately 94% = 1.638 L of air space
Mathematical Based Design Volume of air in both dust off containers is
8.000 L 4” Ballast has 8.091 L of air space 6” Ballast has 1.638 L of air space
Assuming that the ballast tanks may at one point become 100% full, the air in the dust off containers would not be enough to cause the 4” ballast submarine to surface, and it would forever be sunk
The six inch PVC could resurface if 100% full
Prototyping• Everything was cut first• Then all the pieces were assembled• Divide and Conquer• Took 1 ½ months for first prototype
Specs TestPurpose
Verify that the submarine is within dimension constraints
Procedure Measure the length, width, and height
Expected Results Submarine fits within the required
2’x2’x3’ space
Actual Results Submarine fits within the required
2’x2’x3’ space PASS
0
10
20
30
40
Value (in)
Length Height
Dimension Axis
Dimension Test
Data
Constraint
Electrical Safety TestPurpose
Verify that no electrical current was leaking out into the water. Avoid electrical shock
Procedure Using a circuit tester, run one end to ground, and
test the surfaces of the submarine and tether Submerge submarine in water, and test water for a
current
Expected Results No electrical leak
Actual Results Electric wires were fully insulated. No electrical
current found PASS
Operational Ballast TestPurpose
Verify that the submarine can move up and down properly through ballast manipulation
Procedure Set Submarine in water, and connect wiring Open solenoid valves and allow sub to sink Record depth it sank to Resurface
Operational Ballast TestExpected Results
Sink to a depth of 5-10 feet Resurface
Actual Results Did not sink FAIL
Propelled Buoyancy TestPurpose
Ensure buoyancy system is operational during motion
Procedure Attain neutral buoyancy Move in obstacle (cage)
Expected results Pass with obstacle
Results Never Sunk
Stationary Neutral BuoyancyPurpose
Verify buoyancy while not moving
Procedure Attain neutral buoyancy Measure time at neutrally
buoyant
Expected results Prototype attains neutral
buoyancy
Results Never sunk
Three Degrees of FreedomPurpose
Verify the submarine moves along all three axis’ of motion
Procedure Submerge Attain neutral buoyancy Navigate through obstacle Perform 360 degree turn Come back through obstacle Surface
Three Degrees of FreedomExpected Results
Submerge Attain neutral buoyancy Navigate through obstacle Perform 360 degree turn Come back through obstacle Surface
Results Never sunk
Video FeedPurpose
Check webcam is providing input
Procedure Plug in webcam Use geometric shapes to verify input
Expected results Webcam provides input
Results Webcam passed the test, but later was damaged by a water
leak and no footage was recorded for any test
Waterproof Test Purpose
To test the central hull and ballast tanks for leaks. Avoid electrical damage
Procedure Hold submarine vertically Insert into water layer by layer, noting
where water leaked
Expected results No leaks
Results Leaks occurred around bolts and wires Silicone did not seal the submarine