Experimental Study on Pressure Fluctuations in the Shock/boundary Layer Interaction of an Axisymmetric Body

Abstract

The characteristics of the fluctuating pressure for the 15° expansion corner of an axisymmetric body have been investigated experimentally using dynamic pressure measurements and Schlieren photograghs. Data were acquired over a Mach number ranging from 0.8 to 0.92. The angles of attack ranged from 0° to 5°. Pressure signals were measured simultaneously in several positions along the axis of model and were analyzed both in the time and frequency domains. The results indicate that large fluctuating pressure loads, resulting from the shock/boundary layer interaction exist at the transonic flow condition, because of the shock/boundary layer interaction. The maximal pressure fluctuation occurs after the expansion corner at Mach number 0.86. With the Mach number increasing, the position of the normal shock moves downstream. In the shock/boundary layer interaction region, the fluctuating pressure changes significantly with different angles of attack. Moreover, this interaction has a main effect of enhancing the power spectral density in low-frequency range (f≤5KHz).