Critical Design Review Presentation THE UNIVERSITY OF MISSISSIPPI ROCKET REBELS UNIVERSITY STUDENT LAUNCH INITIATIVE
Vehicle Layout and Dimensional Data Structure and Propulsion Total Length 111 in Outer Diameter 6.12 in Dry Weight 32.066 Wet Weight 36.625 lb Motor Choice Loki Research L840CT Motor Impulse 3888 Ns Average Thrust 844 N Burn Time 4.6 sec Recovery System Drogue Chute Design: Hemispherical Main Chute Design Annular w/ Pilot Chute Drogue Chute Diameter 26 in Main Chute OD-ID 9.7 ft 5.93 ft 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 2
Structural Materials Item Airframe Bulkheads Centering Rings and Fins Nose Cone Couplers and Motor Mount Tube Avionics Sled Material HexPly 6376 Prepreg Carbon Fiber/Resin Sheet 5H Plain Weave Carbon Fiber Plate Stock ABA Plastic Filament ABA Plastic Filament Blue Tube ABA Plastic Filament 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 3
Body Tube Specifications Body Tube Section Lengths Fiber Orientation 100% handmade carbon fiber airframe Section Length (inches) Ply Layer Payload Bay 18.5 Ply #1 (28 mil) Main Bay 37 Ply #2 (28 mil) Avionics Ring 3 Ply #3 Drogue Bay 24 (14 mil) Orientation 0 Degrees +45 Degrees 90 Degrees Two thick inner plies serve for structural integrity in both normal and shear stress Thin outer ply allows for smooth outer surface that allows for uniform powder coat Caul plate made prior to airframe layup to ensure smooth outer surface Booster 18 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 4
Features and Dimensions Fin Specifications Type Trapezoidal Root Chord 8 in Tip Chord 4 in Sweep Length 2 in Height 7 in Nose Cone Specifications Nose cone shape Length Wall thickness Nose cone material Base Diameter Shoulder Length Tangent Ogive 9 in.25 in ABA plastic filament 6.12 in 1.5 in 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 5
Motor Mount Assembly Blue tube motor mount tube Will house 75mm motor Features a 3-finned configuration 2 part retainer assembly Metal ring mounts to aft centering ring Polymer screw on cap 3-D printed Fin Configuration Includes fillets and centering rings Will print contours, fillets, and sleeve to fit motor housing 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 6
Final Motor Selection Loki Research L840 Cocktail High quality motor with easy assembly Relatively low average thrust and long burn time Ensures minimal stress on the payload. Motor Impulse Max Thrust Avg. Thrust Burn Time 3888 Ns 1190 N 844 N 4.6 s 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 7
Stability Margin Stability Margin vs. Time 3.5 Stability Margin vs. Time 3 2.5 2 1.5 2.5862 at 0.33 s Rail Exit 3.32 at 4.5512 s Motor Burnout 1 0.5 0 Time (s) 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 8
Additional Data THRUST TO WEIGHT RATIO Wet Weight of Rocket: 36.625 lbf Average Thrust of Motor: 844 N = 190 lbf Thrust to Weight Ratio: 5.18 RAIL EXIT VELOCITY Provided through OpenRocket simulation software: 56 ft/s Rail exit velocity is above the 52 ft/s threshold. 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 9
Mass Statement Booster Section (Body and Coupling Tube, Fins, Motor Mount Assembly w/ motor) Avionics Section (Main and Drogue Body Tube, Avionics Bay and Sled, Drogue Chute Package) Payload Section (Nose Cone, Payload Body Tube and Coupler, FMPA, and Main Parachute Package) Total 264.33 oz (16.52 lb) Pre-burnout 191.33 oz (11.96 lb) Post-burnout 171.09 oz 150.58 oz 586 oz (36.625 lb) Pre-burnout 513 oz (32.063 lb) Post-burnout 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 10
Recovery Expectations and Parachute Sizing Projected Drogue Descent Speed 70 fps Projected Main Descent Speed 20 fps Hemispherical Drogue Parachute Canopy Annular Main Parachute Canopy Led by Small Pilot Chute Attached to 7/8 tubular nylon shock cord Grommets control deployment speed to reduced chance of ripping Drogue Parachute Configuration Hemispherical Main Parachute Configuration Drogue Parachute Diameter 26 in Main Parachute Outer Diameter Drogue Suspension Line 39 in Main Parachute Vent Length Diameter Shock Cord Length 30 ft Main Parachute Canopy Height Shock Cord Material 7/8 Tubular Nylon Main Suspension Line Length Annular with Pilot Chute 9.7 ft 5.93 ft 2.95 ft 12.125 ft 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 11
Avionics Schematics and Ejection Specs. Primary Altimeter PerfectFlite StratoLoggerCF Drogue Bay Volume 466.95 in 3 Backup Altimeter Missile Works RRC3 Xtreme Main Bay Volume 778.25 in 3 Shear Pin Type 4-40 Nylon Drogue Black Powder Mass 1.81 g (rounded to 2 g) Shear Pins per Separation Point 3 Main Black Powder Mass 3.04 g (rounded to 3.5 g) Shear Strength of Pins 50-76 psi 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 12
Packing and Harnesses ¼ Steel Quick Links, ¼ swivel links and 3/8 U-bolts serve as attachment points for shock cord and risers Canopy and suspension lines packed in deployment bags PAI-C-7219B type III para-pak cloth Packages shielded from ejection charge gases with 18 Nomex blankets 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 13
Static Testing 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 14
Kinetic Energy Calculations Section Weight (lbf) Kinetic Energy at Main Parachute Deployment Kinetic Energy on Ground Impact (ft-lbf) (ft-lbf) Booster Section (postburnout) 11.958 910.58 69.94 Avionics Section 10.693 814.26 62.5 Payload Section 9.411 716.63 55.04 Drogue Descent Speed 70 ft/s Main Descent Speed 20 ft/s 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 15
Drift Predictions Wind Speed (mph) Lateral Drift Distance (ft) 0 7 5 100 10 310 15 660 20 1,180 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 16
RED DAWN Subscale Test Flight 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 17
Actual vs Projected Flight Data 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 18
General Dimensions, Projected vs. Actual Data, and Error Analysis Flight Event Simulated Flight Data Actual Flight Data Apogee (ft) 3479 3490 Max Velocity (fps) 486 500 Max Acceleration (ft/s 2 ) 216 225 Flight Time (s) 68.9 120 Drogue Descent Speed (fps) 92.3 49.7 Main Descent Speed (fps) 19.7 17.8 Subscale vehicle is 67% scale of full-scale vehicle. Ballasts and on-board camera replaced scaled weight of FMPA. Descent Speed Discrepancy All other data is accurate to projections. 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 19
FMPA Payload Fragile Material Protection Apparatus Hydraulic system of shock absorbers Houses inner capsule filled with packing peanuts Simple yet functional design, outer and inner ring assembly Easy accessibility, screw off top and large outer ring opening Success Criteria: FMPA can be installed within payload bay Fragile cargo can be easily loaded within FMPA FMPA cargo survives entirety of vehicle flight FMPA and cargo are recoverable. FMPA is reusable. 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 20
FMPA Length FMPA Diameter Payload Dimensional Data 8 in 6 in Capsule Size 3.5 x 5.5 Shock Absorbers Shock Absorber Length Shock Absorber Diameter Ace Controls MA30M, Miniature Series 2.42 in.45 in 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 21
Payload Integration FMPA will be epoxied within the payload bay as shown above. Outer ring allows for easy maneuverability to install or extract fragile cargo from inner capsule. Screw on cap seals cargo snugly with packing peanuts for additional protection 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 22
FMPA Drop Test Objective inspect the receptiveness of the FMPA to shock. Motor impulse will be simulated as impulse from FMPA hitting the ground. Potential energy from specific heights will be synonymous to kinetic energy developed from first second of motor ignition. Fragile material will be loaded after preliminary testing. Independent variables Number and stiffness of shock absorbers. Corrections will be made via increasing/decreasing shock absorbers or installing different shock absorbers with more optimal specifications. 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 23
Interfaces Internal Interfaces Primary Bonds 9394 Epoxy Couplers to body tubes Motor mount assembly Fins to body tube FMPA to body tube Bulkheads to couplers Machine Screws Interface body tubes to flight ready configuration Retainer Assembly Interfaces with motor, aft centering ring, and body tube External Interfaces 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 24
Requirements Verification Status Vehicle Requirements Projected vehicle is below target altitude. Weight reduction analysis in place. Stability, rail exit velocity, and T/W ratio are still within acceptable limits. FMPA was not flown during subscale flight. Ballasted instead. FMPA will be flown on fullscale demonstration flight. Recovery System Requirements Electronic tracking device Experiment Requirements Testing methods confirmed. Materials procured Safety Requirements FMEA, PHA, and Environmental Concerns updated as necessary. General Requirements Spring Educational Engagement Events planned for spring semester. Team Derived Requirements FMPA Construction Underway Testing to begin as soon as prototype is completed. 1/27/2016 2016-2017 USLI CRITICAL DESIGN REVIEW 25