The Effect of Transverse Injection Upstream of an Axisymmetric Aft Wall Angled Cavity in a Supersonic Flow Field

Abstract

Experiments are performed in a supersonic non-reacting flow facility to investigate the performance of an axisymmetric aft wall angled cavity with upstream fuel injection in a Mach 1.8 flow field. The supersonic combustor has a circular cross sectional duct in which cavities are introduced at a distance of 20 mm from the inlet. The aft wall of the cavity is tapered towards flow downstream and inclined with two step consecutive angles. Flush wall mounted injector is mounted at the upstream of the cavity. The tests are conducted at three fuel injection pressures to simulate the flow field in the present study. The mixing performance of the aft wall angled cavities are analysed based on the momentum flux distribution at the exit of the combustor and the stagnation pressure loss across the combustor and compared with the rectangular cavity. Transverse upstream injection of aft wall angled cavities enhances mixing than rectangular cavities, deliberated with less stagnation pressure loss from the former. Increase in injection pressures resulted in more uniform mixing across the flow direction of the combustor irrespective of the cavity configuration, concurrently induces more stagnation pressure loss due to increase in jet penetration depth into the main stream.