Investigation of gel hydrocarbon fuels and hydrogen peroxide as a hypergolic bipropellant

Impinging jet experiments were conducted to characterize ignition delay time for gelled n-dodecane and n-heptane hydrocarbon fuels containing varied sodium borohydride particle loadings, and aqueous solutions of hydrogen peroxide. Experiments indicate average ignition delay times range from approximately 78 down to 26 ms depending on sodium borohydride particle loading and fuel type. Dilution of hydrogen peroxide from 88 to 70 weight percent revealed a significant increase in ignition delay from approximately 21 to 400 ms. Additionally, droplet ignition studies were conducted to investigate alternative additives and oxidizers, in addition to NaBH₄ and H₂O₂, which may impart hypergolic ignition of gel hydrocarbon fuels.