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Solid Rocket Fuel Design, Production, and Testing. March 21, 2019. Team: Amreen Hussaini, Jackson Schleicher, Christopher Jensen, Sergio Sanchez Sponsor: Dr. Nancy Squires and Oregon State University’s High Altitude Rocket Team. Objective. Quantify relative humidity, voidage, and hardness
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Solid Rocket Fuel Design, Production, and Testing March 21, 2019 Team: Amreen Hussaini, Jackson Schleicher, Christopher Jensen, Sergio Sanchez Sponsor: Dr. Nancy Squires and Oregon State University’s High Altitude Rocket Team
Objective • Quantify relative humidity, voidage, and hardness • Decrease error in fuel density
Mixing Procedure • Mix liquid components (10 min) • Vacuum (15 min) • Add metals and mix (10 min) • Vacuum (15 min) • Add oxidizer, burn rate chemicals, and mix (4.5 hours) • Vacuum (15 min) • Add curative and mix (20 min) • Vacuum (15 min) • Pack the fuel Figure 1. Fuel is hand-mixed every 15 minutes during the 4.5 hour
Test Fire • Generate pressure vs. time curves • How we measure success in changes made to fuel recipe or mixing procedure Figure 2: Full-scale test fire at Albany Municipal Airport on March 2, 2019
Changes • Calcium carbonate used as burn rate suppressor • Oxamide used instead • Calcium carbonate causes voids through reaction with water
Results - Density • Theoretical density: 0.060 lb/in3 • Experimental density: 0.056 lb/in3 • 7.8% error in density of fuel with CaCO3 • 7.4% error in density of fuel with oxamide
Results - Hardness Profile • Fuel hardness is critical • Too hard: fuel fractures, then detonates • Too soft: fuel burns, no useable thrust • Historic target hardness zone • 80 - 95 Shore A • We aim to: • Establish ideal hardness performance range • Narrow grain hardness distribution Figure 3: Hardness measurement with durometer
Results - Hardness Profile • Polymer gels harden over time • Non-linear profile • Long-term shelf stability unknown • Hardness stabilized at 5 days • Average: 91.9, n=54 • Range of one sigma: 89.1 - 94.6 • Recommendation: • Long-term monitoring • 1-3 months • Determine shelf stability Figure 4: Hardness profile over 7 days.
Literature • NASA used a simpler formula in their Atlantis solid rocket boosters
Upcoming • Fuel component ratio change • Sub-scale mixes • Test fire grains with oxamide • Generate pressure vs. time curve
Acknowledgements • Dr. Nancy Squires: support and ideas • Dr. Philip Harding: writing and presentation feedback and support • Propulsion Team: expertise on thrust curves and mixing and providing required chemicals for mixing