On the pressure buildup behind an array of perforated plates impinged by a normal shock wave

Abstract

The pressure buildup behind an array of perforated plates following a shock wave impingement was experimentally studied. The experiments were performed in a shock tube facility and the arrays were varied in the number of their perforated plates and the porosities of the plates. It was found that the pressure buildup behind all of the configurations that were examined displayed similar characteristics. Using simplified assumptions about the nature of the flow through the perforated plates array, we could account for the influence of the volume confined between the plates, and the porosity of the plates. Once accounted for, experiments were performed with argon and SF6, in addition to air, in order to examine the effect of the gas. It was found that the pressure buildup depended on a constant parameter, which was gas-dependent. The constant parameter for each gas was found in this study experimentally. To the best of our knowledge this result has never been reported before. The large spread of different experiments performed throughout the present study enabled the separation of the effects facilitated by the perforated plates array into two distinct processes that affected the pressure buildup at the end-wall. The first was the diffraction of the incident shock wave and subsequent shock reverberations that were found to depend on the number of perforated plates in the array and their porosity. The second was the inhibition of the flow through the perforated plate that was found to depend on the confined volume, type of gas and the porosity of the plates.