Direct numerical simulation of the stability of zero-pressure-gradient boundary layer over corrugated wall using the immersed interface method

The influences of surface corrugations on zero-pressure-gradient boundary-layer instability were examined numerically by solving the two-dimensional compressible Navier-Stokes equations. immersed interface method with compact filter and characteristic boundary condition (NSCBC) was newly proposed applied. Two kinds computation made: a channel flow to validate numerical scheme used layer over corrugated whose amplitude less than 10% thickness wavelength ranged from half double T-S wavelength. Linear stability analyses based parabolized equations (PSE) also made see how critically corrugation modified neutral curves. results showed that characteristics waves in wall excellent agreement linear theory, thus verifying accuracy present scheme. destabilized significantly due positive energy production occurring just behind crest. PSE well described development surface. When height 3%, 5% 7% thickness, critical Reynolds number displacement about 4%, 14% 19% lower for smooth surface, respectively, while destabilization effect weakly dependent It found transient distance change geometry much shorter flows flow; 4% same order as TS wave, nature became case entire at 4 times beginning corrugation, which 1/5 channel.