Linear and non-linear disturbance evolution in a compressible boundary-layer with localized roughness

摘要

A numerical investigation of disturbance amplification in a laminar compressible flat-plate boundary layer with a localized two-dimensional roughness is carried out. Both linear and weakly non-linear disturbance evolution are considered. The non-linear case exhibits a secondary subharmonic resonance. In addition to deterministic simulations, a stochastic approach is applied. The random parameter is chosen to be the height of the roughness in the linear case, while in the non-linear case the amplitude of the primary disturbance is considered a random parameter.