Experimental study of the influence of small angles of attack and cone nose bluntness on the stabilization of hypersonic boundary layer with passive porous coating

The present work was devoted to an experimental study of small angles of attack and cone nose bluntness on the efficiency of stabilization of high-frequency disturbances in hypersonic boundary layer with a passive porous coating. The experiments were carried out on a cone with an apex half-angle 7° and nose bluntness radii R = 0.03, 0.5 and 1 mm installed under angles of attack α = 0–1° at the freestream Mach number M∞ = 5.8. High-frequency pressure fluctuations on the sides of the cone with the solid and porous surfaces were measured. It is shown that at all angles of attack and cone bluntness, the passive porous coating permits an efficient suppression of disturbances in hypersonic boundary layer both on the windward and leeward sides of the cone.