高超声速圆锥边界层转捩反转数值研究

In order to study the transition reversal phenomenon in the transition of the hypersonic boundary layer, based on the Reynolds average N-S equation, the flow around a hypersonic cone was numerically simulated with a γ transition model, obtaining the changing law of the transition position of the cone boundary layer with the attack angle and the bluntness of the head, and analyzing the flow mechanism of the transition and reversal phenomenon of the cone boundary layer. The results show that, when the bluntness of the cone head increases to a certain value, the transition position of the cone boundary layer presents a reversal phenomenon, i.e. the windward surface advances and the leeward surface delays with the increase of the angle of attack. And when the attack angle reversal phenomenon occurs in the cone boundary layer transition, the friction coefficient on the windward surface is significantly greater than that of the leeward surface, and the friction change is greater before and after the transition, so as to pay attention on the thermal protection of the windward surface. Under the condition of zero angle of attack, the transition position of the cone boundary layer can show an "N" type reversal phenomenon with increasing the bluntness of the cone head gradually from a very small value. When the bluntness of the cone head increases to a certain value, the transition reversal phenomenon of the boundary layer occurs, may be caused by the significant increase in the height of the entropy layer after the head shock.