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1 Preliminary Design Review (PDR) The University Of Michigan 2011
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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.
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7 Launch Vehicle Verification Vehicle/Payload design justification Static stability analysis Materials/system justification (discussed in further detail in proceeding slides)
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8 Vehicle Design Justification Different ideas for reducing drag Requirements ◦Stable ◦Fast ◦Precise ◦Consistent ◦Highly variable
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9 Vehicle Materials NoseconePolystyrene Plastic Body Blue Tube (Apogee Comp.) CansBlue Tube (Apogee Comp.) FinsG10 fiberglass
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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
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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 Drogueless ◦500 Feet Main Parachute Double Redundancy ◦Flight computer ◦Altimeter Apogee 500 Feet
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13 Vehicle Safety Verification Plan This matrix shows detrimental failures in red, recoverable failures in yellow, and failures with a minimal effect in green
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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
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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
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16 Thrust-To-Weight Ratio
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17 Rail Exit Velocity Rail Exit Velocity:85.1 ft/s Rail Length:10 ft
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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 ◦@ 400 feet 1 Backup Apogee TB Main Chute TB AvBay Flight Computer Competition Altimeter 9V Batteries Positive TB
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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
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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
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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.
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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
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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
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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
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Controls – Dynamic Target
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Controls – Restrained Controller
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Controls - Physics
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Controls –Instrument Uncertainty
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Controls – Apogee Calculation
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33 Flight Avionics Competition Altimeter Drag Computer Drag Servo 9V Batteries Drag Servo Drag Computer Competition Altimeter
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34 Propulsion Select a motor such that it will allow our rocket to exceed one mile in our minimum drag configuration
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35 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
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36 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
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37 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
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