59 / 2019-09-17 22:07:33

A numerical study of roughness induced transition in supersonic boundary layer

Transition, roughness, supersonic boundary layer

Roughness plays an important role on boundary layer transition. To understand the effect of roughness on supersonic boundary layer, roughness of ramp and a new kind of pairing gears with different height and interval are investigated. In order to understand the transition mechanism, wake instabilities behind the isolated roughness are analyzed using bi-global stability method. To follow the transition process and flow structure evolution both in time and space, high order finite difference method of weighted essentially non-oscillatory (WENO) is utilized. Large scale structures are visualized with Q2 method. It is found that the new paring gears roughness behave better than ramp device at the same height.