Experimental investigation of the influence of the passive porous coating on laminar-turbulent transition of the hypersonic boundary layer of the sharp cone at angles of attack

The problem of the delaying laminar to turbulent transition by the passive porous coating on the sharp cone at the angle of attack has been studied for the first time. Experiments are conducted in a Transit-M hypersonic short-duration wind tunnel at the Mach number 5.9. The boundary layer laminar-turbulent transition is determined by heat flux distribution on the surface of the cone. It is found that the transition on the porous surface in compare to smooth surface has been delaying on the windward side at the 0.5°, 1° and on leeward side at the 0.5°. There is no effect of the porous coating on the location of the laminar to turbulent transition at angle of attack 1°.