Numerical investigation of shock wave interactions with square barrier–end wall systems

Protective barriers have been used to deflect the shock waves produced by blasts away from potential targets in military, aerospace, and civil infrastructure. The force and impulse imparted on the target (end wall) are closely linked to the reflections, diffraction, and reverberations of shocks in the barrier-end wall system. This study focuses on numerically solving the Euler equations for the flow field and end wall dynamics developed when an incident normal shock interacts with a square (or cube) barrier-end wall system in two- and three-dimensional domains. Visualizations of various quantities like density gradient, vorticity magnitude, Qcriterion, etc. were produced for a set of barrier coverage and separation values to examine the flow field, along with evaluation of force and impulse on the end wall. Force and impulse are found to be amplified compared to the absence of coverage for the set of parameters present. The amplification results from shocklets that reverberate in the barrier-end wall pocket. The reverberating shocklets are further trapped by vortex rings formed around the barrier, giving rise to complex shockvortex interactions. These results can further support the case for using CFD to optimize barrier placement and coverage and inform additional analyses that rely on the flow physics of the system.