Abstract:In order to study the impact of different ejecting state on aerodynamic heating of hypersonic aircrafts,the square/circle hole ejecting under hypersonic flow condition was numerically simulated. The impacts of ejecting pressure, ejecting velocity and ejecting direction to the main flow field were discussed and the flow field structure, wall heat flux and center line temperature at different ejecting state were obtained. The results show that gas ejection can relieve the aerodynamic heating situation of wall to some extent. The cooling effect at whole wall ejection is remarkable. And the wall heat flux reduces nearly two-thirds when the ejecting velocity is about 1 m·s-1. Moreover, at high ejecting velocity (Ma>1), the cooling effect is strengthened by increasing the ejecting pressure and velocity appropriately. At low ejecting velocity (Ma<0.6), the ejection flows within the boundary layer, and has a weak influence on the main flow field structure; the greater the ejecting velocity is, the bigger the range of cooling is, and the better the cooling effect is. The cooling effect of downstream is better when the ejecting direction is acute angle, and the cooling effect of upstream is better when the ejecting direction is obtuse angle.