Supersonic turbulent boundary layer under conditions of distributed positive air mass transfer through a permeable surface

The paper presents experimental study on efficiency of controlling a supersonic turbulent boundary layer on a flat surface by positive-directed air mass transfer via a finely perforated wall. Experiments were performed for a flow with Mach number 2 and the unit Reynolds number equal 12.5·10 6 m −1 . The mass transfer intensity was varied in the interval from 0 to 0.00941. There is a significant effect of mass transfer on the skin friction coefficient: the end of active control zone demonstrates a reduction in friction by 80 % as compared to baseline data. It was discovered that the spontaneous mass transfer (due to a natural difference between the barometric pressure and static pressure in the test section) can provide a considerable reduction in the skin friction coefficient down to the zero level by the end of the control zone.