Absolute instabilities and transition in a rotating cavity with throughflow

Abstract

High precision direct numerical simulations (DNS) of the boundary layer flow in a rotating cavity are carried above the expected critical Reynolds number for transition from convective to absolute behaviour. The sustained presence of an absolute mode of crossflow instabilty is observed, associated with saturation and progressive spectrum broadening, due to non-linear effects. Eventually, the flow settles in a solution exhibiting properties consistent with a global non-linear mode.