A laboratory setup was constructed to study shock wave coalescence and the resulting focusing behavior when multiple shock waves collide. This was accomplished by generating multiple cylindrical shocks in air by an array of exploding wires. The exploding wires were placed concentrically around a target with the goal of generating high temperatures and pressures at the target while reducing collateral damage in regions away from the target. Both the number of wires and their initiation times were varied in order to study the resulting focusing process. High-speed schlieren photography was used to determine the speed and shape of the coalescent shock fronts. A quantitative background oriented schlieren technique was used to determine the density and pressure distribution during the focusing phase. In addition to validating results of numerical models and simulations, the experiment was able to determine the pressure distribution for converging shock fronts under conditions in which the gas can no longer be assumed to be calorically perfect, and for which numerical modeling is considerably more difficult.
