Greg HydeRaymond ZhengJoseph RojanoKatie BentleyLori Liebman

P14414P3 ARBORLOO WIND RESISTANCE TEST

STANDDETAILED DESIGN REVIEW

Introduction

Engineering Requirements

Detailed Design Review Objectives

Revisiting CFD Analysis

System Architecture

Scaled Test Stand Design

Fullscale Test Stand Design

Test Plans/Procedures

Risk Analysis

Project Plan

Moving Forward

Summary

OVERVIEW

TEAM INTRODUCTIONS

Member Major Role

Greg Hyde Industrial Engineer

Project Manager

Raymond Zheng

Mechanical Engineer

Lead Engineer

Joseph Rojano Mechanical Engineer

EDGE Master

Katie Bentley Mechanical Engineer

Engineer

Lori Liebman Mechanical Engineer

Engineer

• Measure wind speed, forces of aerodynamic effects

• Create test procedure for full size and scale testing

• Recommendations for future design of arborloos

PROBLEM STATEMENTThe primary objective of this project is to design a scale model and a full-size test stand that will help determine the wind resistance of various arborloo designs. The scale model test stand should replicate the forces experienced by a Class I hurricane, and the results should be easily comparable to the lower speed, full-size results.

ENGINEERING REQUIREMENTSSpec

Number Source Specification Direction Units of Measure

Marginal Value

Ideal Value

S1 CN1, CN2 Fluid speed range maximize mph 85 95

S2 CN1, CN2 Record time range maximize minutes 1 20

S3 CN1, CN2 Measure range of forces at base/tie downs maximize Newtons 70 50

S4 CN8 Storage volume minimize ft^3 5 4.45

S5 CN12 Set up time of test rig minimize min 25 20

S6 CN11 Required technicians to set up minimize persons 4 2

S7 CN3, CN4 Safely contain all flying debris that may occur maximize N/A N/A N/A

S8 CN10 Cost of entire system minimize $ 800 600

S9 CN10 Cost of most expensive component minimize $ 300 100

S10 CN13 Lifespan (hours of operation) maximize hrs 45 50

S11 CN9 Percent of students that can safely assemble the test rig maximize percent 85(for now) 100

S12 CN14,CN2 Measure range of forces of projectiles maximize N/A N/A N/A

S13 CN5 Size/shape compatibility maximize # of arborloos 1 10

S14 CN6 Weight compatibility maximize lbs 30 20

S15 CN7 Can use existing RIT equipment boolean % of material used 0.6 0.75

From this review, the team hopes to:• Present final design for small scale testing and receive feedback • Present draft design for full scale testing and model• Solicit ideas for implementation for full scale testing• Get recommendations from arborloo base teams on future

possible arborloo design configurations• Receive input on test plans / procedure

DETAILED DESIGN REVIEW OBJECTIVES

SCALING LAWS 

• Dimensional Analysis – allows for identification of key parameters

• Reynolds Number allows to determine model test velocity given a full size expected velocity

• Drag Coefficient allows us to find the expected full size drag force given the model measured drag force

REVISITING CFD ANALYSIS

Pressure Distribution mainly constant with fast drop offs at edgesAid in placement of pressure reading points

CFD Results showed a CD of approximately 1. Will assume a conservative 1.5.Dynamic Pressure at 95 mph wind expected to be ~1 kPa. Dynamic Pressure at 20 mph wind expected to be ~ 50Pa

REVISITING CFD ANALYSIS

Fox & McDonaldVideo

CH7 MODERATE SPEED FLOW

Fox & McDonaldVideo

CH7 HIGH SPEED FLOW

• Use a load cell to directly find the drag force on the arborloo

• Load cell assembly also used as attachment point for arborloo

• Use pressure sensors to verify CFD results

• Pressure sensors methodology will allow for comparison to full

scale testing

TACKLING THE PROBLEM

SYSTEM ARCHITECTURE

• This design contains:– Plywood Base– Load Cell Assembly– Pressure Sensor– Pressure Multi-sensor

• Looking for feedback on:– Assembly package quality– Full scale testing – Testing equipment choices & improvements

SCALED TEST STAND DESIGN OVERVIEW

• RIT Wind Tunnel• Test Model will need to be about 1.2 ft tall max (1/6th

scale)

SCALED TEST STAND DESIGN Specs Addressed :S7

SCALED TEST STAND DESIGN

TEST ARBORLOO• Plywood Model

– 6” x 6” x 12”

– Uses pressure sensors and load cell

to ensure accuracy of data

Specs Addressed :S3,S4,S13,S14

Mechanical Load Ratings:• Fx ,Fy = 120 N• Fz = 240 N• Mx ,My = 6.0N·m• Mz = 6.0 N·m

LOAD CELL SPECIFICATIONS

Specs Addressed :S3

FD = ½ρV2AcD

= 0.5*(1.225 kg/m^3)*(42.4688m/s)2 *(0.3048m*0.1524m)(1.5) – Conservative

= 77.0 N = 17lbf ✔M = FD*L

= (77N)*(0.1524m) – Half the height of the arborloo= 11.7 N·m ✗

EXPECTED LOADS

Adjustable Height Load Cell Assembly allows adjusting

moment armSpecs Addressed :S3

• Sensor relay provided by Prof. Wellin

• Functions as a giant valve, opening and closing inputs to one pressure output

• Hooked up to an Omega PX277-30D5V Pressure Transducer

• Pressure transducer outputs to DAQ that feeds into the computer

PRESSURE MULTI-SENSOR

Specs Addressed :S3

• Pressure sensors will give general pressure distribution• Surface area of arborloo face is known

– 1/6 scale: Area=18 in^2 = 0.0116 m^2 • Expected Dynamic Pressure:

Q= ½ ρV2 = 0.5*(1.225kg/m^3)*(42.4688m/s)2 = 1.104 kPa• Pressure Rating: 10 psi differential ~70 kPa ✓• Average Pressure x Area = Distributed Force

PRESSURE SENSOR

• Expected Dynamic Pressure:

0.5*(1.225kg/m^3)*(42.4688m/s)2 = 1.104

kPa

• Omega PX277-30D5V• Pressure overload 10psi = 68.95 kPa• 1.104 kPa << 68.95 kPa

PRESSURE TRANSDUCER

• Mounted in wind tunnel behind test stand

• Cost: ~$200 each

• Used to verify windspeed at arborloo

• Can also measure temperature

ANEMOMETER

Specs Addressed :S1,S15

DATA ACQUISITION DEVICE

• DAQ Device: NI: USB-6008

– Multifunction Data Acquisition

– Compatible with pressure sensors

– No added cost to design

– Made to be used with LabView Specs Addressed :S1,S2,S3, S15

PRESSURE SENSOR VIRTUAL INSTRUMENT

Script inputs:PressureForce

Code outputs: Drag Force, Coefficient of Drag, Stress

MATLAB CODES FOR DATA ANALYSIS

Specs Addressed :S1,S2,S15

PROCESS MAP

PRELIMINARY TEST PROCEDURE 10. Use Thermometer to measure room temperature. Room temperature must be between 60°F and 80 °F. 11. Load software and calibrate all sensors. See “Future MSDII Document on Guidelines for calibrating sensors”.

12. Close plexiglass walls and secure control surface. 13. Turn on Wind tunnel. Push start button and use arrows to increase or decrease wind speed. Read anemometer so that the desired wind speed is achieved. Wait 2-3 minutes for steady conditions to apply. 14. Start collecting data. 15. Let test run, recommended time for test duration is 5 minutes. Note: Do not run wind tunnel for longer than 20 minutes as this may cause overheating. 16. Stop collecting data. 17. Turn off Wind tunnel. Push stop button. 18. Repeat for different arborloo model.

Instructions: 1. Release pneumatic hold by turning the pressure knob counter-clockwise to the left position. 2. Lower the pistons by holding onto the red button. 3. Insert and align plywood base into wind tunnel test section. Handle plywood with care. 4. Raise the pistons by holding onto the green button. 5. Lock the pneumatic pistons by turning the pressure knob clockwise to the right position. 6. Attach load cell assembly to plywood base through the bottom. Fasten securely. 7. Attach load cell assembly to the “shelf” inserted close to the center of arborloo design. See “Future MSDII Document on Guidelines for creating an attachable arborloo”. 8. Attach barbs to face of arborloo facing the wind. Use specified barb size only. See “Future MSDII Document on Guidelines for placing Pressure Sensors”.

9. Attach and secure anemometer inside the wind tunnel away from the test arborloo.

LIMITATIONS OF DESIGN • Inability to compare small

scale results to large scale result for non-sharp edged objects i.e. cylindrical arborloos.

• Windtunnel max speeds of approximately only 120 mph.

• Design Includes– Large Scale Arborloo Sarah will provide

– Self standing – sand bags– Utilize Pressure Sensors methodology

– Netting environment for protection

– Locking mechanism for equipment

– Dynamic Pressure at 20 mph wind expected to be ~ 50Pa

– Drag Force ~ 123 N

DESIGN OVERVIEW - FULL SCALE

POSSIBLE TESTING LOCATIONSA. Ramp BLDG 7A-7BB. Soccer / Track FieldC. SAUD. Turf FieldE. Meadow / Hill

BOM

BOM /

Specs Addressed :S8, S9

BOM /

Specs Addressed :S8, S9

TEST PLANS

RISK ANALYSIS

RISK ANALYSIS

PROJECT PLAN

MSD II-Week 1-3• Test Small Scale Model in

Wind Tunnel• Analyze Data• Begin Full Scale model

creation

Over Break:• Order necessary parts• Have machine shop make

necessary parts

MOVING FORWARD

Introduction

Engineering Requirements

Detailed Design Review Objectives

Revisiting CFD Analysis

System Architecture

Scaled Test Stand Design

Fullscale Test Stand Design

Test Plans/Procedures

Risk Analysis

Project Plan

Moving Forward

SUMMARY

QUESTIONS?