Evaluation of a Hybrid-Piston Pulsed Detonation Engine

Abstract : Experiments are conducted on a hybrid piston-pulsed detonation engine to evaluate the power extraction and system interaction issues. The hybrid engine is constructed using a four-cylinder motorcycle engine with a spacer block between the valves and pistons. Four detonation tubes, one for each cylinder, are placed perpendicular to the direction of the piston navel. A deflagration to detonation transition (DDT) is used to achieve detonations. The piston is in the deflagration region of the DDT. This hybrid engine has a critical starting frequency. Above this frequency the engine will self-activate and produce excess power. Below this frequency, the power produced is less than that required to self-activate and the engine decelerates after the starter motor is disengaged. The hybrid piston-pulsed-detonation-engine constructed for these experiments is capable of producing 20 hp and 50 lbf of thrust simultaneously.