Hypersonic Boundary-Layer Stability with Local Cooling and Local Metasurface Treatment

Modern aviation is interested in sustained flight within the atmosphere at hypersonic speeds. However, several aerodynamic challenges prevent the efficient operation of hypersonic vehicles. One of the significant challenges is the laminar to turbulent boundary layer transition, which increases heat transfer and aerodynamic drag. The hypersonic boundary layer transitions occur primarily due to Mack’s first and second modes. Stabilization of these modes is, therefore, of great interest. In this study, we investigated the stabilization effect of the local cooling strip and local metasurface over a flat plate and 5-deg half-angle blunt wedge with a nose radius of 0.0254 mm. We employed a high-order accurate flow solver to calculate the steady flow for a free-stream Mach number of 6.0 and a unit Reynolds number of 25.59 × 106/m. The results showed that local cooling-local metasurface (LC-LM) treatment for the hypersonic boundary layer inhibits the first- and second-mode growth. Moreover, the amplitude of instability waves inside the boundary layer at the end of the computational domain remained below the initial disturbance amplitude.