转捩诱导法向力及其对细长尖锥气动特性的影响

边界层转捩时,是否会出现诱导法向气动载荷,这是一个很有意义的问题。本文介绍了在高超音速风洞中完成的静态气动力实验与动态气动力实验,它证实这种诱导法向载荷是存在的,是边界层转捩的不对称性造成的,并对细长锥的气动特性有明显而呈规律性的影响。

TRANSITION INDUCED NORMAL FORCE AND IT'S EFFECTS ON SLENDER SHARP CONE AERODYNAMIC

Dynamic tests have showed that the transition effects of the boundary layer on dynamic and static stability of a slender sharp cone are significant and regular. It was considered that there is a transition induced normal force at the transition zone.In order to conform this transition induced normal force, some static and dynamic test have been performed. The test results indicate that the transition induced normal force is really existent, which have a direction opposite to the inviscid flow normal force and caused by the asymmetric transition at leeward side and windward side of the cone.It is this transition induced normal force, that make the CNa-Re Curve has a valley in the middle Re Number which the transition exists on the surface of the cone; when the transition exists on the after body, the static stability decrease, the dynamic stability increase, but when the transition occurs forward of the center of gravity, the static stability increase, the dynamic stability decrease: when the transition is at the downstream of the inviscid flow pressure center, the viscous flow pressure center move forward from the inviscid flow pressure center, when the transition is at the upstream, the viscous pressure center move backward.The tests were performed in a supersonic and hypersonic wind tunnel, Mach Number is 5. The model is a 10 degree half angle sharp cone.