Predicting pressure buildup behind perforated plates under blast wave impact: A simplified approach

This study experimentally investigates the interaction of an incident blast wave with a perforated multiple plate array and the subsequent pressure buildup on an end wall. Experiments are conducted in a square tunnel using arrays composed of plates with varying porosities and perforation diameters positioned at different distances from the end wall. High-speed shadowgraphy and pressure measurements quantify the influence of these parameters on transmitted wave attenuation and pressure buildup on the end wall. Results demonstrate that wave attenuation and pressure buildup rates are significantly influenced by plate porosity, array length, and stand-off distance, whereas the perforation diameter has a negligible effect. A theoretical model is employed to predict the measured end wall pressure history. The model accurately predicts overall pressure history, including peak pressure and decay, for various porosities, plate numbers, and stand-off distances. Deviations between model predictions and experimental data are analyzed. Additionally, the pressure measurements reveal a power-law relationship between the transmitted wave attenuation rate and the porosity index. Notably, arrays with lower porosity, consisting of fewer plates, can effectively attenuate the transmitted wave compared to higher porosity configurations with more plates. By attenuating the peak pressure on the target wall/end wall and extending the pressure buildup time, the perforated plate arrays provide a promising approach to enhance blast protection.