Numerical investigation on properties of attack angle for hypersonic vehicle

The steady inviscid flow field of hypersonic vehicle was numerically simulated by using two-dimensional coupling implicit Euler equations,which were discredited by the second order upwind scheme.The effects of variable attack angle(-10°～7°) on flight performance of the hypersonic vehicle under three kinds of working conditions were analyzed,i.e.inlet cut-off,engine through-flow,engine ignition.The results show that when attack angle of the engine increases from-10°to 7°,the lift coefficient and lift-drag ratio continuously increase;the pitching moment coefficient first increases,then decreases;under the condition of inlet cut-off,the drag coefficient of the vehicle continuously increase with the increase of attack angle;under two other working conditions,the drag coefficient of the vehicle first increases with the increase of attack angle,then decreases,and the change is slow.As a whole,the drag coefficient of the vehicle under three kinds of working conditions all increase with the increase of attack angle.