High-resolution nonlinear nonlocal instability analysis of crossflow-dominated transition scenarios

Abstract

Crossflow-dominated laminar-turbulent transition in three-dimensional boundary layers is studied by nonlinear parabolized stability equations (PSE). It is demonstrated that the strongly nonlinear stages of the transition process, i.e. the formation of high-frequency secondary instabilities, their linear and nonlinear growth as well as the subsequent disintegration of the secondary disturbance structures which is accompanied by a degradation of the stationary crossflow vortices can be modelled by this type approach provided that sufficiently high resolution in modal space is used.