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Critical Design Review (CDR). Charger Rocket Works University of Alabama in Huntsville NASA Student Launch 2013-14. Kenneth LeBlanc (Project Lead) Brian Roy (Safety Officer) Chris Spalding (Design Lead) Chad O’Brien (Analysis Lead) Wesley Cobb (Payload Lead).
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Critical Design Review (CDR) Charger Rocket Works University of Alabama in Huntsville NASA Student Launch 2013-14 Kenneth LeBlanc (Project Lead) Brian Roy (Safety Officer) Chris Spalding (Design Lead) Chad O’Brien (Analysis Lead) Wesley Cobb (Payload Lead)
Prometheus Flight Overview Payloads Here
Technology Readiness Level http://web.archive.org/web/20051206035043/http://as.nasa.gov/aboutus/trl-introduction.html
Outreach • Adaptable for different ages and lengths • Beginning outreach packet with Elementary School • Building the program from the ground up with school advisers • Supporting activity • Water Rockets • Completed • Science Olympiad • 102 Middle School • 54 High School • Scheduled • Challenger Elementary
Analysis Responsibilities • Fin Flutter Analysis • RockSim/Open Rocket Trajectory Simulations • MATLAB 3DOF Simulations • Monte Carlo Simulations • FEA Analysis using MSC PATRAN and NASTRAN • CFD Analysis using CFD-ACE+
Flight Trajectory • Max Altitude: 15800 ft • Max Velocity: 1600 ft/s, Mach: 1.45 • Acceleration: 40 G
Vehicle Aerodynamics – M4770 • Static Margin – 1.61 • CP – 92 in • CG– 84.4in • Thrust To Weight • Max Thrust – 1316 lbf T2W: 40 • Average Thrust – 1073 lbf T2W: 33.5 • Exit Rail Velocity – 122 fps
Final Motor Selection - CTI M4770-P • ISP – 208.3s • Loaded Weight: 14.337 lb • Propellant Weight: 7.3 lb • Max Thrust: 1362 lbf
Proof of Randomization in Inputs • Shows output consistency overmultiple sets of simulations.
Variation in Flight Time • Time variance directlyaffects the radial landingdistance.
CFD - Critical Mach Number *Steady state values Indicated by color maps
CFD – AerothermalHeating *Steady state values Indicated by color maps
CFD - Drag vs Mach Plot • Uncertainty with Mach < 0.5 • Inadequate convergence in low Mach Regime
Recovery System • Single Separation Point • Main Parachute • Hemispherical • 12 ft • Cd 1.2 • Nylon • Drogue Parachute • Conic • 2.5 ft • Cd 0.71 (experimentally determined) • Nylon
Recovery System Deployment Process • Stage 1 • 2 seconds after apogee • nose cone separates • release the drogue • Stage 2 • 2.1 • Drogue attached via tethers. • 2.2 • A black powder charge separates the tethers • Stage 3 • Main parachute pulled from deployment bag Eye bolt Drogue L.H.D.S Main Parachute InDeployment bag Tethers Black Powder Charge
Deployment Process Stage 2.1 Stage 1: Drogue Deployment Stage 3 Stage 2.2
Sewing Technique • Seam Type: French Fell • Vent Hole supported with double stitched bias tapes • The bottom edge hemmed • Prevent fraying • Increase durability Stich Seam Cross Section
Subscale Drogue • Flight Test • Built by team • First attempt • Subscale Data • Perfect flight Altimeter • Cd of 0.71 • 27.5” Diameter
Construction Materials • Swivel ultimate load:1045 lbs • The nylon line anchor points ultimate load: 120 lbs per strap • The eyebolt ultimate load: 500 lbs
Hardware Team responsibilities: • Vehicle design • Testing and verification of materials and components • Vehicle construction • Interfaces • Design Details: • 34lbs • 40Gs acceleration • Geometric similarity to NASA Nanolaunchprotoype • Nanolaunch team requested maximum use of SLS printed titanium
Thrust Ring • Printed titanium • Analyzed with FEA • Significantly stronger than required
Fin Assemblies • Modified significantly since PDR due to updated geometry from Nanolaunch team (bolted instead of epoxied) • Easier to inspect and verify • Fin replacement in the field now possible • Moderate weight penalty compared to original design.
Body Tube • Carbon composite • FEA, destructive testing and hand calculations done to assess strength • Large margin of safety and low weight
Payload Shaft • 7075-T6 Aluminum threaded shaft • Preloaded in tension • FEA and hand calculations show significantly over strength requirements
Payload Shaft Load Paths • Carries thrust loads into payloads and recovery forces into lower rocket, as well as providing assembly method for payloads, body tubes and recovery harness • Red Arrow indicates motor loads from thrust ring through body tube • Green arrow indicates motor loads passed through payloads • Blue arrow indicates recovery forces passed through payload shaft • Orange arrow indicates motor case retention force
Coupler Rings • Machined aluminum • Aft coupler retained by payload shaft preload • Fore coupler retained by nose cone shaft and shear pins
Nose Cone Assembly • All components retained by shaft similar to payload shaft • Carbon fiber nose cone shroud and bulkhead • Contains pitot pressure and accelerometer/ gyro data package
Pitot Probe • Allows measurement of static pressure along with supersonic AND subsonic total pressure • Unique and original design which could only be made with 3D printing techniques • Helps fulfill our Nanolaunchrequest to explore selective laser sintering in original ways.
Carbon fiber dog bones • Loaded in tension • Verify tensile strength of materials • Tubes • Loaded in compression • Verify compressive strength of representative structures of body tube • 45/45 Sleeve • 0/90 Wrapped • Parachute Material • Loaded in tension • Verify parachute material and seam strength Structure Testing
Tension Results Fractures Dog bones • Verified Strength Requirements • Fractures showed uniformity in the angle of the fibers • Calculated Young Modulus to be 309 ksi Fractures
Tubes • Wrapped tube holds the most force • Fractures showed uniformity in the angle of the fibers • Failure Load: 8094.5 (lbf) Compression Results Fractures
Parachute Results Seam Test • Seam failed before material • Breaking of seam occurred at 35 lbf • Narrow sample failed at seam due to edge effects
Structure Testing Conclusions Verified Requirements • Strength • Thickness • Fiber Angle • Fabrication Future Testing • Recovery system • Electronic payload • Verification of flight hardware • Flight testing completed rocket
Recovery Hardware Testing CRW Built Parachute Deployment Bag Failure Point Separation Charges • Problems with deployment bag. • Successful proof of concept flight for parachute design. • Successful test of separation charges.
Subscale Flight Data • Apogee: 1,573 feet AGL. • Max Velocity: 279 ft/s. • Time of Flight: 63.9 seconds. • Motor: CTI I-205. • Recorded Using a PerfectFlite SL100 • Apogee: 4,156 feet AGL. • Max Velocity: 597 ft/s. • Time of Flight: 128.6 seconds. • Motor: Aerotech I-600. • Recorded Using a PerfectFliteSL100