Compressibility Effects on Asymmetric Wakes of Cones at Low Angles of Attack

A computational analysis is performed to study how compressibility effects influence vortex asymmetry which develops in the wakes of axisymmetric forebodies at low angles of attack (AoA). An 8 degree sharp nose cone at an angle of attack, AoA = 15 degree, is tested at three different freestream Mach numbers, M = 0.6, 1.1, and M = 2. The effects of compressibility prove to be a significant factor in minimizing asymmetric flow features. Results revealed that vortex size, spacing and orientation is highly Mach number dependent, as the compressibility stabilizes wake turbulence. Surface pressure profiles reveal that the separation of the flow corresponding to the near-body vortex is delayed with an increase in Mach number. The location of vortex breakdown moves further downstream as Mach number increases. Mean flow evaluation indicates that as the Mach number increases, there is a notable decrease in strength of the off-body vortex, as the near-body vortex gains strength. Unsteadiness of the near-wall dynamics are captured through pressure spectra and reveal a range of high frequencies which characterize the interaction of vortical structures spawning from vortex breakdown and the presence of cross-flow vortices generated in the windward side boundary layer