University of Florida Rocket Team Third General Body Meeting October 10, 2013

1. University of Florida Rocket Team Third General Body MeetingOctober 10, 2013

2. Today’s Meeting • Project Updates • Design Opportunities • “Office Hours” • Presentations • Motor Basics • OpenRocket • Recovery

3. Updates Hybrid Competition Propulsions Research • Bringing 8 teams • Six highest altitude • Two 2,000 feet • Meeting yesterday Sugar Motors Potential launch

4. Static Motor Test Stand • Variable motor diameter • 24mm-98mm • Withstand 3000 N with reasonable factor of safety • Operate upwards and downwards • Measure force over time (load cell) • Clamp into ground.

5. Static Motor Data Acquisition • LabVIEW VI • Measure and interpret data from the load cell • NI DAQ (OOTB or 6009) • Needs to determine • Total Impulse • Average Thrust • Max Thrust • Thrust Curve • Burn Time

6. Fin Mount Apparatus • Apparatus to help mount fins symmetrically • Multiple rockets • Either 3 or 4 fins • Multiple body diameters/motor mount tubes • Account for changing location of centering rings

7. “Office Hours” MAE A 211 Monday, 9:30 AM – 12:00 PM Tuesday, 2:30 – 4:00 PM Friday, 9:30 AM – 12:00 PM

8. Propulsion Basics of Rocket motors

9. How Rockets Work Newton’s Third Law of Motion: For every action there is an equal and opposite reaction Rocket motor = energy conversion device - Matter (solid or liquid) is burned, producing hot gases. - Gases are accumulated within the combustion chamber until enough pressure builds up to force a part of them out an exhaust port (a nozzle) - Thrust is generated by a pressure buildup within the combustion chamber and by mass ejection through the nozzle. - Combustion chamber geometry, throat diameter, and nozzle geometry govern performance and efficiency (Conservation of Momentum-Fluids)

10. Different Types of Motors

11. Solid Motor Basics

12. Bates Grains

13. Rocketry • Model Rocketry • Uses motors A-G • Anyone can launch • Class 1 • Is made of paper, wood, or breakable plastic • Uses a slow burning propellant • High Powered Rocketry • Needs certifications • Uses motor more than 160 N-seconds of total impulse • Uses motor more than 80 N average thrust • Exceeds 125 g of propellant • Uses hybrid motor • Rocket weighs more than 1500 g • Includes any airframe parts of ductile metal • Class 2

14. High Powered Rocketry • Level Certifications • Level 1- Uses H (320 N-seconds) or I motors (640 N-seconds) • Level 2- J, K, L • Level 3- M, N, O • Beyond O is Class 3 and requires waivers (total impulse greater than 40,960 N-seconds) • Numbers of Motor • Example H64-8 • H is the total impulse (between 160-320 N-s) • 64 N is the average thrust • 8 seconds is the delay ejection charge • To determine motor burn divide total impulse by average thrust

15. OpenRocket Introduction to flight Dynamics

16. Recovery An Introduction to the recovery subsystem

17. Recovery A reliable system to safely land the rocket. “Must be reusable without repairs.”

18. Goal • Consistently return a rocket to the ground without damage to the rocket or objects on the ground. • Critical for continued testing of payload

19. Possible Designs • Featherweight Recovery • Small rockets • Flutter down • Tumble Recovery • System induces tumble • Nose-Blow Recovery • Nosecone induces tumble • Parachute • Ejected from rocket • Increases drag • Glide Recovery • Airfoil deployed

20. Possible Designs Continued • Helicopter Recovery • Blades deployed • Rocket autorotates

21. Dual Deployment

22. Rocket undergoes powered and unpowered ascension

23. Ascension • During ascension rocket naturally orients itself into wind • Drifts an amount up range depending on wind speed

24. Altimeter detects apogee and sets off ejection charges. The nose cone is ejected and the drogue parachute is deployed

25. Apogee • Apogee is highest point the rocket attains • Apogee is detected by the altimeter • Altimeter controls the ejection charges

26. Ejection charges • Forces the shear pins to break and deploys the drogue parachute • E-fuses are detonated by the altimeter • Charge Types • Black Powder Substitutes • CO2 Canister

27. Charge Testing

28. Drogue parachute • Smaller X-Form Parachute • Sufficiently lowers the speed without a large horizontal drift • Deployed at apogee

29. Selecting parachute size FD = ½(r)(Cd)(A)v2 FG= mg FD=FG ½(r)(Cd)(A)v2=mg A=πD2/4 D = sqrt( (8mg) / (π*r*Cd*v2) ) V= sqrt( (8 m g) / (π*r*Cd*D2) ) Cd=Coefficient of Drag r=density of air v=velocity

30. At a preset attitude, around 700ft, the second ejection charge will deploy the main parachute

31. Main Parachute • Detonated by the altimeter at a specified altitude • Also uses ejection charges to deploy • Allows for a much slower descent rate

32. Rocket is located and recovered

33. Locating the rocket • Transmits GPS coordinates to locate the landed rocket

34. Meeting • Begin the design phase of the recovery sub-system • Friday Oct, 11 • 5:00PM Library West Room 230

35. Upcoming Meetings Propulsions Research Right here, right now (brief) CanSats Tuesday, Oct. 15, 6:30 at the Energy Park GBM Thursday, Oct. 24, 6:15 in Little 121