Effects of Attack Angle on Starting Performance of a Hypersonic Inlet

Abstract

Since the boundary of an inlet starting Mach number cannot be obtained easily in high speed wind tunnels. The correlations between changing the attack angle and changing the freestream Mach number which affect the starting performance of a 2-D hypersonic inlet were investigated. The results show that the attack angle limit for unstarting and self-starting of the inlet at Mach 5.9 flow are in the range of 12o-14o and 0o-1o, respectively. The effective flow Mach numbers at the entrance of the inner contraction of the inlet are reasonably consistent at the unstarting limit and the self-starting limit, either by changing attack angles or freestream Mach numbers. One can try to change the attack angle within a certain range in wind tunnels to obtain the starting behaviors of a 2-D inlet at different freestream Mach numbers.