Alternative Pulse Detonation Engine Ignition System Investigation Through Detonation Splitting - August J Rolling

A Pulse Detonation Engine (PDE) combusts fuel air mixtures through a form of combustion: detonation. The resulting change in momentum produces thrust. Recent PDE research has focused on designing working subsystems. This investigation continued this trend by examining ignition system alternatives. Existing designs required spark plugs in each separate thrust tube to ignite premixed reactants. A single thrust tube could require the spark plug to fire hundreds of times per second for long durations. The goal was to minimize complexity and increase reliability by limiting the number of ignition sources. This research examined using a continuously propagating detonation wave as both a thrust mechanism and an ignition system requiring only one initial ignition source. This investigation was a proof of concept for such an ignition system. First a systematic look at single tube geometric effects on detonations was made. These results were used to further examine configurations for splitting detonations, physically dividing one detonation wave into two separate detonation waves. With this knowledge a dual thrust tube system was built and tested proving that a single spark could be used to initiate detonation in separate thrust tubes. Finally, a new tripping device for better deflagration to detonation transition (DDT) was examined. Existing devices induced DDT axially. The new device attempted to reflect an incoming detonation to initiate direct DDT in a cross flow.