Effects of free-stream velocity and pressure gradients on MHD boundary-layer control

A steady two-dimensional MHD boundary-layer flow on a flat plate with varying hydrostatic pressure and free-stream velocity along the plate and a uniform transpiration through the plate is considered. The momentum boundary-layer thickness is found to increase substantially with injection and negative flow-shape factors. However, it decreases with increasing magnetic interaction numbers. Transpiration, flow-shape factor, as well as magnetic interaction number strongly affect the shearing stress at the wall. Injection and retarding free-stream velocity will enhance the chances of a flow separation, while the magnetic interation number will do just the opposite