Low-frequency, spanwise oscillation in a finite-width cavity at Mach 1.5

A joint experimental–computational program examined low-frequency, spanwise oscillations in supersonic flow over a finite-width cavity. Lowpass-filtered rear wall surface pressure revealed that shear layer impingement was most often biased to one side of the wall, switching sides at frequency two orders magnitude below resonance. Therefore, bifurcation into spanwise-asymmetric, mirrored, quasi-steady states could be defined. The were described by impingement/ejection near asymmetry layer, and centrifugal inner-cavity flow. Resonance amplitudes also found spatially modulated low-frequency switching. yawed inflow force asymmetric states.