Effect of compressibility on instability of boundary layer over a spinning cone in hypersonic flow

Spinning vehicles achieve gyroscopic effects by rotating around their axis. However, transition significantly influences the stability of flight. In this work, a study of instability on the unstable modes in boundary layers over a rotating cone with a 7° half-apex angle in hypersonic flows is presented with linear instability analysis (LST). To quantify the effect of compressibility, Mach numbers (5-10) are considered, and a higher rotational velocity is considered for analysis of centrifugal mode. MMM, CFM, and CM shift towards low frequency, low streamwise, and circumferential wavenumbers. Also, the maximum amplification rate of MMM, CFM, and CM decreases with Mach number, suggesting a stabilizing effect of compressibility on the boundary layer over a spinning cone in hypersonic flows.