1 Preliminary Design Review (PDR) The University Of Michigan
2011
Slide 2
2 Vehicle: i.
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3 Vehicle: ii. Nose Main Chute Separation Bay Main Chute
Separation
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4 Vehicle: iii. Main Chute Seperation Aviation Bay Aviation Bay
Access Cut Apogee Separation Apogee Separation Bay
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5 Vehicle: iv. Apogee Separation Motor Apogee Separation
Bay
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6 Vehicle Dimensions Body Tube 5.5 in dia. Can 2.0 in dia.
Slide 7
7 Launch Vehicle Verification Vehicle/Payload design
justification Static stability analysis Materials/system
justification (discussed in further detail in proceeding
slides)
Slide 8
8 Vehicle Design Justification Different ideas for reducing
drag Requirements Stable Fast Precise Consistent Highly
variable
Slide 9
9 Vehicle Materials NoseconePolystyrene Plastic Body Blue Tube
(Apogee Comp.) CansBlue Tube (Apogee Comp.) FinsG10 fiberglass
Slide 10
10 Material Justifications Phenolic Tubing Cured paper fibers
Cheapest, strong, brittle Blue Tube 2.0 High-density paper More
expensive, durable, dense Carbon Fiber Strands of woven carbon Most
expensive, strongest, labor-intensive
Slide 11
11 Static Stability Margin 1.5 in neutral configuration
pre-launch 2.4 after engine burnout Drag mechanism actuated RockSim
estimated CP/CG locations On the unstable side Add mass to nose of
rocket
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12 Recovery Scheme Two Separations Apogee Drogue-less 500 Feet
Main Parachute Double Redundancy Flight computer Altimeter Apogee
500 Feet
Slide 13
13 Vehicle Safety Verification Plan This matrix shows
detrimental failures in red, recoverable failures in yellow, and
failures with a minimal effect in green
Slide 14
14 Testing Plans Ground test proper body tube separation during
E-Charge ignition Use a multimeter to measure the current the
Flight Computer sends to each E- Charge during ground simulations
Servo selection through torque testing on flap from collected
simulation/wind tunnel data
Slide 15
15 Motor Selection Motor Manufacturer: Loki Motor
Designation:L1482-SM Total Impulse:868.7 lb-s Mass pre/post
burn:Pre:7.8 lb Post:3.8 lb Motor Retention System: Aero Pack
RA75
18 Recovery Avionics Raven Flight Computer Competition
Altimeter 4 Total E-Charges 2 from Flight Computer 2 from Altimeter
1 Main Apogee Charge @ 5280 feet 1 Backup 1 Main Chute Charge @ 500
feet 1 Backup Apogee TB Main Chute TB AvBay Flight Computer
Competition Altimeter 9V Batteries Positive TB
Slide 19
19 Aerodynamics-Linear Flaps: i. Flap Geometry 0% closed
corresponds to the position where the flap is not exposed to air
flow 100% closed corresponds to where the flap is fully extended
into the flow FlapMax % Closed Flap End Geometry Can Inner Dia [in]
Flap Width [in] A100Semi-Circle1.504 B100Semi-Circle2.551
C65Rectangular2.551 D75Rectangular2.5512.051
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20 Aerodynamics-Linear Flaps: ii. Flap A Flap B
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21 Aerodynamics-Linear Flaps: iii. Flap CFlap D
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22 Aerodynamics-Linear Flaps: iv. Drag data from cases run at
300 m/s FlapMaximum Drag [N] A81.7235 B240.396 C204.086 D197.838
*NOTE: All flap data is for one flap and all rocket data is for
half-body
Slide 23
23 Aerodynamics-Rotating Flaps: i. Moment Concerns with the y
component of the force generated by the flap at various angles
Analyzed at the most extreme case (largest can and flap size at 45
) Force in the y direction caused by the flap angle deflection is
negated by the force it creates on the wall of the can
ComponentForce in y-direction [N] Rocket-199.8 Flap199.61 *NOTE:
All data is from a simulated wind speed of 300 m/s
Slide 24
24 Aerodynamics-Rotating Flaps: ii. ANSYS Fluent CFD mesh sizes
were refined in areas of interest such as the flap and the interior
wall for optimal results.
Slide 25
25 Structures-Can Analysis Analyzed the worst case scenario
(flaps 100% closed) Pressure forces in front of the valve are not a
concern Low pressure pockets behind the valve are not a
concern
Slide 26
26 Controls: i. Proportional Integral Derivative (PID)
controller that will induce pressure drag as a means of regulating
vehicle altitude Drag is calculated dynamically during flight
Controller should respond to physical system changes in no more
than 50 milliseconds and recover within 2% of the goal
altitude
Slide 27
27 Controls-System Model: ii. Dynamic Apogee-Rectifying
Targeting (DART) Control System Dynamic Target : Used to aid in
assuring the mean energy path solution is followed Restrained
Controller : Proportional Integral Derivative (PID) derived
controller with physical limits Physics Plant : Simulation of
vehicle-environment interaction given controller commands
Instrument Uncertainty : Propagation of instrument uncertainty into
system values Alt. Projection : Projection of rocket apogee
altitude with same physics plant model for consistency
34 Payload Design Drag Control System Actuating flaps located
within side cans to control drag Control system will activate under
specific altitude and/or velocity conditions
Slide 35
35 Payload Test Plan i. Flap Drag Testing Simulations/flow
characterization using compressible flow in ANSYS Fluent CFD over a
range of Mach numbers Test drag flap mechanism in various
configurations to confirm results from simulated model Produce a
function for control system relative to drag, flow speed and flap
deflection
Slide 36
36 Payload Test Plan ii. Drag Flap Control System Testing 4
constants to vary (Kp, Ki, Kd, Dt) N^4 simulations for N possible
different constants Parallel processing in Matlab to tackle Monte
Carlo simulation NYX / FLUX supercomputers from UM Center for
Advance Computing used to tune constants for best performance
Slide 37
37 Outreach Project We have contacted a teacher at a high
school that has agreed to make rocketry a unit in his class. We
plan to go in and teach about the basics of rocketry. We are aiming
to have the students work in groups and design rockets to
eventually launch in a class competition. We also plan to outreach
to lower level grades and invite them to the final launch. The
point is to get kids excited about rocketry. We want the entire
district to participate.