Comparison of plasma ignition parameters and firing performance with 20and 60-mm electrothermal-chemical guns

Two electrothermal-chemical gun systems of 20- and 60-mm calibers have been operated with different pulse power supplies at 35 and 10 kV, respectively. Dissimilarities of the injected current behavior during plasma ignition by exploding wires are reviewed. The effects of the varied plasma energy and increased loading density of consolidated propellant charges are analyzed with regard to the resulting pressure development. The improvement of the firing performance with the larger caliber still remains less satisfying. However, empirical regression functions have been found that approximate the kinetic muzzle energy as a function of the maximum pressure in the combustion chamber and can be useful for predictions.