Transition Triggered by Isolated Roughness Element Using Improved Delayed Detached Eddy Simulation Model

Abstract

Hypersonic boundary layer transition from laminar to turbulent induced by a cylindrical roughness element is investigated using direct numerical simulation based on a finite volume formulation. To explore the transition mechanism and capture the shock wave at the same time, high order MDCD (minimum dispersion and controllable dissipation) scheme is applied. The numerical results show that the transition is dominated by the instabilities of both the horseshoe vortex and the shear layer around the roughness. Qualitative and quantitative comparisons are made between simulations and experiments, and the normalized root-mean-square pressure coefficients agree well with experiments in the region around the cylindrical element.