University of Florida Rocket Team Second General Body Meeting September 27, 2013

1. University of Florida Rocket TeamSecond General Body MeetingSeptember 27, 2013

2. Overview Energy Research and Education Park Sugar Motor Demonstration CanSat Details Rocketry Basics and Structures

3. Energy Park • Off-campus facility for the Rocket Team • Our own office • Shared manufacturing space • Drill Presses • Table Saw • Circular Saw • Belt Sander • Hand Tools • Hardware • Where we store rockets and equipment

4. Directions  2701 SW 23rd Terrace, Building 241

5. Sugar Motors Thursday, Oct. 3rd, at 6:00 Energy Park Jimmy Yawn (www.jamesyawn.net) Make and test some propellant

6. CanSat • Target Altitude: 1000 ft. • Payload Specifications • 0.5-1.1 kg • Cylinder •  63.5 mm diameter • About 122 mm high • Recoverable (Dedicated Parachute) • H class motor • Sketches/OpenRocket • Lauren’s email: lekrueger@ufl.edu

7. Next GBM and Other Events • 3rd GBM • Thursday, October 10th, 6:15 PM • Little 0121 • Lessons • Propulsion • Flight Dynamics • Recovery • SpaceX info session • 10/1, 6:15, Little 109 • Rocket team interns • Career Showcase • 10/2, O’Connell Center

8. Rocketry: The Basics Brittney Lane LEAD STRUCTURES ENGINEER

9. Key Vocabulary Apogee- the highest altitude that the rocket reaches in its ascent Drag- the force that resists the motion of the vehicle through the air and opposes thrust; due primarily to friction between the surface of the vehicle and the fluid through which it travels, air Thrust- upward force generated by motor Center of Gravity (CG)- Point at which you can balance the rocket on one finger. The rocket rotates around this point during flight. Center of Pressure (CP)- Point at which all of the forces (Drag, Thrust, Lift) can be realized as one point. The sum of all of the forces acting on the rocket occurs at the center of pressure.

10. Building a Rocket: THE MAIN PARTS

11. Nosecone • Very important for aerodynamics; design to reduce drag • Drag is related to the surface area of the nosecone and velocity • Different shapes of nosecones: • Ogive (most common) • Parabolic • Cone • Attached to parachute • Use lightweight material like plastic

12. Body Tube/ “Airframe” Cylindrical body of rocket that houses the parachutes, avionics bay, payload bay, motor and more Length and weight affect flight performance Use durable but lightweight materials: plastic, Blue Tube, phenolic tubing, etc

13. Avionics Bay Houses all the electronics of the rocket Located between two bulk heads Must be easily accessible for quick repairs or rewiring Secured to airframe with screws or shear pins

14. Fins • Add to stability of rocket • Typically 3-4 fins • Lightweight and durable materials (wood, G-10 fiberglass) • Usually attached to body with epoxy • Many different shapes: • Trapezoidal • Triangular • irregular

15. Motor Retention Motor tube made of stiff cardboard is secured inside of body tube with epoxy between centering rings. Motor tube holds the motor in the rocket safely and keeps it centered. Transfers thrust from motor to rocket. The motor is kept from falling out of the rocket after burnout with screws, hooks, caps, etc.

16. Building a Rocket: THE DESIGN

17. How to Begin • Consider the purpose of your rocket and what it must hold to determine the minimum length and size • Ex. Satellite or quadcopter inside, 4 ft diameter parachute, 20 ft of shock cord • Consider cost constraints in selecting materials or designing parts that need to be manufactured

18. Stability • Stability Margin = (Distance between CG and CP)/(Body Tube Diameter) • <1 : Under stable • 1-3 : Good range for model rocketry • >3 : Over stable • CG is above CP

19. Solidworks Software Open Rocket Free software Helpful in determining stability and testing rocket with different motors Used to design parts to be manufactured in the shop To create a detailed full-scale model

20. Building a Rocket: OTHER USEFUL PARTS

21. Bulkheads Used to separate sections of the rocket (payload bay, avionics bay, etc)

22. Centering Ring To center the motor tube in the body of the rocket Used to secure motor tube in place so that thrust is transferred from the motor to the rocket

23. Railbuttons Used to put the rocket onto the launch rod Keeps the rocket on a straight, controlled path during lift off

24. Building a Rocket: MACHINES AND TOOLS

25. Table Saw • Used for cutting fins, making slots in body tube, cutting motor tube, etc • Safety: • Wear safety glasses • Do not wear gloves or loose clothing • Wait until the blade stops moving before removing your work piece • Make straight cuts only

26. Drill Press • Used for drilling holes, cutting out bulkheads, centering rings, etc • Safety: • Wear safety glasses • Do not wear gloves or loose clothing • Wait until the bit stops spinning before removing or inspecting your work piece

27. Sander • Used for sanding down fins, smoothing edges, adjusting bulkheads/centering rings, etc • Safety: • Wear safety glasses • Do not wear gloves or loose clothing • Wear mask so as not to inhale particles for certain materials • Keep your hand at a safe distance from the sander • Turn it off when you finish

28. The Flight: PHASES AND EVENTS

29. Phases of Flight • Powered Ascent – Rocket is being forced upwards by the motor’s thrust force. • Unpowered Ascent (coast) – Rocket continues upward due to its vertical momentum. Motor is no longer burning. • Descent– Rocket has separated and is now falling to the ground at a much slower rate due to the deployment of parachutes.

30. The Physics • Lift- relatively small force (since the flight is almost vertical); generated by the fins • Weight- depends on materials and construction • Fg = mg • Drag- the force that resists the motion • FD= (1/2)ρv2 CD A • ρ= density of fluid • v = velocity • CD = drag coefficient • A = area • Thrust- upward force generated by motor; depends on motor choice