Impact of Bluntness on the Stability of Thermo-Chemical Non-Equilibrium Flow

The influence of nose bluntness on the linear stability of a Mach 10 flat plate boundary layer in thermo‐chemical nonequilibrium is investigated. The base flow is computed with a finite‐volume solver that accounts for vibrational excitation and molecular dissociation, and an in-house local linear stability solver is extended to include thermo‐chemical nonequilibrium effects. Preliminary validation of the linear stability solver is performed. Two nose bluntness radii, 5 mm and 50 mm, with wall‐to‐edge temperature ratios of 0.86 and 0.81, respectively, are investigated. The relative Mach number reaches unity only for the 5 mm case. This suggests a link between supersonic‐mode onset and the local edge Mach number. Both blunt noses also exhibit an unstable fast acoustic mode.