Effect of Mach Number on Stability of Boundary Layer Over a Rotating 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 in hypersonic flows was presented with linear stability theory (LST).To quantify the effect of Mach number，Mach numbers 5~10 were considered，and a higher rotational velocity was considered for analysis of centrifugal mode.The influence of Mach number on different stability modes varies，which was confirmed with LST analysis.Modified Mack mode，cross-flow mode and centrifugal mode shift towards low frequency，low streamwise and circumferential wavenumbers.Also，maximum amplification rate of modified Mack mode，cross-flow mode and centrifugal mode decrease with Mach number.Meanwhile，oblique wave instinct of second mode is uncovered，and wave angle of second mode decreases with Mach number.