Numerical simulation on effects of oscillatory angle of attack on performance of hypersonic inlet

Since the oscillation of angle of attack will bring adverse effects on the performance of hypersonic inlet,computational fluid dynamics method and overlapping grid method are used to investigate the oscillations of the aerodynamic forces,pressure recovery coefficient and mass flow coefficient of a typical 2D inlet.The effects of frequency at 10,20,40 Hz and amplitude at 3°and 5°on inlet performance parameters are given in this paper,differences between climb phase with Ma∞=4 and H=17 km and cruise phase with Ma∞=6 and H=28 km of hypersonic aircraft are also presented.The results show that large oscillation occurs on aerodynamic force,pressure recovery coefficient and mass flow coefficient under the unsteady movement.These adverse effects will bring much challenge to the hypersonic craft and engine design if the oscillation of angle of attack could not be avoid.