Combustion effects of a staged transverse jet and pulsed detonation in supersonic crossflow

The combustion effects of a H-2/O-2 pulsed detonation (PD) staged downstream of a primary transverse H 2 jet in supersonic crossflow (JICF) was investigated. A Mach 2.35 crossflow representative of Mach 7 flight combustor entry conditions (T-infinity = 1330 K, P-infinity = 40 kPa) was considered. The jet-to-crossflow momentum flux ratio (J(j)) of the primary jet was varied between 0.5 and 5.0 to span different stabilization modes. The PD provides a short-duration, high temperature and momentum, radical-rich plume of gas to the wake of the primary transverse jet. The temporal evolution of the interaction between the two plumes was studied using high-speed schlieren and OH* chemiluminescence imaging. Phase-locked OH planar laser-induced fluorescence imaging was used to identify the instantaneous reaction zone along the center-plane at various times of the blowdown process. It was found that the interaction of the two plumes promotes earlier ignition and release of heat. The presence of a high momentum flux ratio transverse jet increases the effective blowdown period (EBP) over which OH* is exhausted; thus increasing the duration of the effects of the PD on the JICF. Lastly, the penetration of the reacting layer into the crossflow was observed to increase with the staged PD present as compared to cases without it. (C) 2016 by The Combustion Institute. Published by Elsevier Inc.