Engineering estimation of fluctuating loads in shock wave/turbulent boundary-layer interactions

Abstract

In an earlier experimental study of the flow upstream of a blunt fin in a Mach 5 turbulent boundary layer, the authors showed that the low-frequency (below 4 kHz) component of the fluctuating wall pressures can be attributed largely to an instantaneous pressure distribution P i , which expands and contracts as its upstream boundary translates aperiodically between the upstream influence and separation lines. Based on the physical similarity between P i and the time-averaged (mean) wall pressure distribution, the authors demonstrated the feasibility of predicting fluctuating pressure loads using mean wall pressure distributions obtained from either computation or experiment. The objective of the present study was to determine whether the approach is applicable to a broader range of flows involving shock wave/turbulent boundary-layer interaction. For all cases examined, the locations of local maxima and minima in the measured wall pressure standard deviation distributions were estimated correctly. Further, quantitatively accurate estimates of the magnitude of fluctuating wall pressure and heat transfer levels were obtained using the corresponding time-averaged distributions.