Flow characteristics of an air jet in a Mach 3 crossflow

Abstract

The unsteady wake and wall pressures surrounding sonic injection into supersonic crossflow were investigated in experiments and LES simulations. The experiments and simulations were conducted in a Mach 3 flow with a 2 Bar sonic injector. Experimental wall-normal pressure profiles downstream of an jet inlet show lower pressures within the boundary layer region compared to the no-injection case, and an increase in pressure above that of the freestream values in the region passing through the jet plume. Mass flux spectra in the jet plume, and wall pressure spectra around the inlet show a significant broadband increase due to injection. The rise in wall pressure fluctuation intensity was greater closer to the jet, with the spectra returning to undisturbed levels much more gradually downstream of the inlet compared to upstream. Similar trends were also observed in the RMS wall pressure measurements.