1. Land Wind Racer Design RideWy University of Wyoming College of Engineering and Applied Sciences EPSCoR Undergraduate Research Day April 21, 2012 1

2. RideWy Team Mechanical Engineering Austin Rykhus – Frame Design and construction Lee Mitchell – Brake Design Energy Systems Engineering Nick James –Stability and Steering Design Shyla Allen – Sail Design Sponsors Z4 Energy Georgia Gayle Kevin Luke Advisors Dr. Naughton Dr. Garnich Mr. Morton 2

3. Celebration of Wind Race Rules Wind powered 3 to 84 wheels, 5” or larger All human crew, or as close as possible Equipped with braking & steering Assume liability for themselves & crew No commercial vehicles 3

4. Celebration of Wind Race Rules Carry 1 person over course Height < 13.5 ft No chewing tobacco if the wind >15 knots (to avoid splashing the spectators) Points deducted for: Destroying spectators Biting Kicking Striking Gouging BRIBES will be taken into consideration 4

5. Land Wind Racer Design 5

6. Design Specifications Lessons Learned Design Approach Modeling Compliance Testing Alterations Finished Product 6 Overview

7. Design Specifications Z4 Specifications ≤ 80 lb f weight 4 ft x 6 ft footprint “WIN the RACE” RideWy Specifications 13 mph average tailwind 40 mph maximum tailwind 1.2 minimum FOS 7

8. Lessons Learned User Interface Rider capabilities Steering Braking Sail Rigging Sitting position Frame Weight and transport Sail design Head Clearance 8

9. Design Approach 3 vs. 4 wheels 3 wheel inverted tricycle design Lightweight, stable, and simple Sail Spinnaker sail – tailwind application Braking – front vs. rear Dual front brakes – majority of brake force Steering Rear steering – simplicity 9

10. Modeling – The Sail VAVA VSVS VTVT β V S /V T =3 VSVS VTVT VariableDefinition VSVS Velocity of Racer VTVT Wind Velocity VAVA Apparent Wind 10

11. Modeling – The Sail VariableDefinition CTCT Lift and Drag Coefficient ASAS Wind Velocity VAVA Apparent Wind 11

12. Modeling – Braking System Front disc brakes with foot pedal Sum the horizontal forces about the racer’s front wheel Sum the moments about the front axle for vertical forces VariableDefinition FfFf Friction Force FnFn Normal force FbFb Brake Force MBrake Moment cgcg Center of Gravity rbrb Brake Disc Radius h wind Height of Wind force µCoefficient of Friction 12 M rbrb F n,fw wind Cg

13. Applied braking force Stopping distance Sail dropped, not accelerating forward Racer velocity = 20 mph, µ = 0.65 F b = 98 lb f SD = 7.5 ft 13 Modeling – Braking System VariableDefinition FfFf Friction Force FbFb Brake Force mvmv Mass of Racer rbrb Brake Disc Radius IMoment of Inertia αAngular Acceleration VsVs Velocity of Racer SDStopping Distance μCoefficient Of Friction

14. Modeling – Stability VariableDefinition L CG Distance to center of gravity FbFb Brake force FtFt Driving force from sail hHeight of point force of sail ѲsѲs Angle of F t 14 Cg

15. Modeling –Steering 15

16. Modeling – Steering VariableDefinition VTVT Tangential velocity RTRT Turning radius mTotal mass Velocity (mph)Turning Radius (ft)Restoring Torque (ft-lbf) 10204.2 ± 0.6 255011± 1.3 16

17. Modeling Lateral Wheel Forces VariableDefinition F Y2 Cornering force at front wheel N FW Normal force at front wheel R FW Front wheel radius θ cam Camber angle 17

18. Compare and Validate each model Beam analysis Finite Element Analysis in SolidWorks Frame Analysis 18

19. T –Frame Analysis Not accounting for the beam slope or deformation at this point m1m1 Rider mass m2m2 Mast mass m3m3 Front axle mass R y_1 Reaction force in the y-direction R y-2 Reaction force in the y-direction W 1, W 2 Frame distributed load X1X1 Distance to mass 1 X2X2 Distance to the mast M Moment about the mast in the y- direction 19

20. MATLAB T Design m 1 =140 lb f m 2 =13 lb f M=F t *5.7 ft F t =20 lb f Diagrams Shear Moment Results σ’ =8300 psi FOS=4.9 T –Frame Analysis 20

21. Frame Analysis Stress analysis on frame using SolidWorks Simulation FEA T Design m 1 =140 lb f m 2 =13 lb f M=F t *5.7 ft F t =20 lb f Results σ’ =7700 psi FOS=5.4 21 Beam Analysis and FEA was performed on the Delta Design

22. Comparing Frame Analysis T – Frame Weight: 28 lb f 1.6-1.9 FOS Delta Frame Weight: 31 lb f 1.8-2.0 FOS 22

23. Fabrication Construction began February 22, 2012 Components fabricated Frame Running gear Wheels & brakes Modified bike components Sail – Club 420 modified 23

24. Compliance Testing Sail Testing Sail mounted to support post Sail force using force dynamometer Results Wind = 7.5 mph, 20 lb f Frame Testing Frame fixed to ground Forces applied & deflection recorded Results 150 lb f rider, 70 lb f wind – 0.05 inches Linear behavior – elastic strain region Theoretical results 150 lb f rider, 70 lb f wind – 0.03 inches 24

25. Tipping Testing Rear wheel fixed, racer rotation about right front wheel 150 lb f rider Dynamometer pulled on mast until tipped Results – Side load Modeled force = 35 lbf Tested force = 32 lbf Compliance Testing Brake Testing 150 lb f rider Force dynamometer pulled to measure brake resistance Results Modeled force = 98 lb f Tested force = 53 lb f Stopping Distance = 10.5 ft 25

26. Alterations Made After Testing The foot rest and braking pedal Ergonomic issues Sail control Add line guides to front axle Steering geometry Improve restoring force 26

27. Finished Product 27

28. Sponsors Z4 Energy Sponsorship & Funding North Sails & Sail Newport Spinnaker Sail Mckims’s Upholstery Seat Upholstery Department of Family and Consumer Sciences Dr. Sonya Meyer Dr. Donna Brown Sail Alterations Moonbuggy Team Wheels and Brakes 28

29. Special Thanks Faculty & Shop Technicians Dr. Erikson Mr. Allen Mr. Schilt Mr. Dauer Mr. Morton Dr. Naughton Dr. Garnich 29

30. Questions! 30