Spatial simulation of nonlinear instability in plane channel flow

A direct numerical simulation was performed to investigate the effect of focal wall suction/blowing on the transition in a plane channel flow. The nonlinear Navier-Stokes equations were solved in a spatially-evolving channel flow. A Tollmien-Schlichting wave was superimposed on the laminar channel flow at the inflow. At the outflow, the buffer domain technique was applied to suppress the reflection of outgoing waves. The influence of the local suction/blowing on the linear and nonlinear instabilities of the flow was examined. The nonlinear effects of the initial T-S wave amplitude on the subcritical channel flow were scrutinized