An effect of base hole size on dynamic test results

This paper presents the dynamic test results of a flat-base sharp cone model hole diameters. The test Mach number is M = 5.047; cone semiangle is 10 deg; and the free-flow Reynolds number based on the model length is (2.2-13.3) x 10 to the 6th. The results show that the effect of the base hole diameter on test data really exists. In general, when the boundary-layer transition occurs on the aft surface of the model, the effect is obvious; with increasing hole diameter the static stability decreases and the dynamic stability increases. When the transition moves forward, the effect becomes unimportant. The mechanism of the effect is discussed briefly.