Characterization and performance of a liguid hydrocarbon-fueled pulse detonation rocket engine

Abstract

A liquid hydrocarbon-fueled PDRE was built and successfully tested at the Naval Postgraduate Schoolαs Rocket Propulsion and Combustion Laboratory. The first time use of a new electro-hydraulic liquid fuel injector was demonstrated to produce consistent atomization properties while allowing for varying fuel injection durations at frequencies up to 50Hz. Planar laser-induced fluorescence and high-speed imaging were used to characterize the injection flow paths of this injector. Using gaseous ethylene as a baseline for comparison, the PDRE was operated at various equivalence ratios and frequencies up to 40 Hz. Operation in partial fill scenarios was successfully conducted and found to deliver a decreased impulse linearly related to the percentage fill. A series of tests was conducted using liquid JP-10 and RP-1 fuels over varying oxidizer-to-fuel ratio. The higher pressures, wave speeds, and resulting impulse measurements revealed the benefits of using high energy density hydrocarbon fuels. The difficulty in detonating these fuels was demonstrated and overcome using a variety of different geometries and hardware configurations.