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Cavity Ignition In Supersonic Flow By Spark Discharge And Pulse Detonation, Timothy M. Ombrello, Campbell D. Carter, Chung-Jen Tam, Kuang-Yu Hsu

U.S. Air Force Research

Ignition of an ethylene fueled cavity in a supersonic flow was achieved through the application of two energy deposition techniques: a spark discharge and pulse detonator (PD). High-frequency shadowgraph and chemiluminescence imaging showed that the spark discharge ignition was passive with the ignition kernel and ensuing flame propagation following the cavity flowfield. The PD produced a high-pressure and temperature exhaust that allowed for ignition at lower tunnel temperatures and pressures than the spark discharge, but also caused significant disruption to the cavity flowfield dynamics. Under certain cavity fueling conditions a multiple regime ignition process occurred with the PD that led …