Drag coefficient of an absorbing plate set transverse to a flow

Supersonic flow past an absorbing surface is considered. The flow past a plate set transverse to the oncoming stream is calculated on the basis of a model kinetic equation. It is found that the dependence of the drag coefficient on the surface adsorption coefficient qualitatively changes on transition from the free molecular to the continuum flow regime. It is shown that in dense media a drag coefficient maximum is reached at total gas absorption by the surface. Under these conditions the surface interacts with the undisturbed stream. The effect of the extent of the plate-produced disturbance region on the plate drag is investigated.