Boundary-Layer Separation Due to Combustion-Induced Pressure Rise in a Supersonic Flow

The HyShot supersonic combustion experiments were conducted in the T4 Stalker tube at the University of Queensland, Australia, to test supersonic combustion in a constant-area duct of rectangular cross section. The intake was deigned to spill both the compression shock and the boundary layers formed on the intake surfaces and to generate new boundary layers on the four walls of the combustor. Fuel was injected perpendicularly to the oncoming flow from four 2mm porthole fuel injectors located 40mm from the leading edge of the combustor. Choking of the combustor, attributed to boundary-layer separation due to combustion-induced pressure rises, is identified to occur within the test period in 12 fuel-on shots. The 95% confidence-interval uncertainty is estimated to be ∓11%, taking into account the uncertainty in flow conditions and pressure measurements.