Numerical simulation on the pressure wave in a 30 mm electrothermal-chemical gun with the discharge rod plasma generator

Abstract

Abstract An axisymmetric two-dimensional (2D) internal ballistic model including the transient burning rate law is used to simulate the 30 mm electrothermal-chemical (ETC) launch with the discharge rod plasma generator (DRPG). The relationship between the pressure wave and the initial parameters, such as input electric power, discharging timing sequence, loading density and propellant web thickness, is researched through the change of initial parameters in the model. In the condition of synchronous discharging, the maximum of the pressure wave can be controlled while the ratio of the input electric energy to the propellant chemical energy (electric energy ratio) is less than 0.11. If the electric energy ratio is larger than 0.11, the maximum of the pressure wave increases rapidly with the electric energy ratio. With the increasing of the electric energy ratio, the change of the first negative amplitude value can be ignored. In the condition of timing sequence discharging, the allowed input electric energy ratio to control the pressure wave is proportional to the current pulse duration. At the high electric energy ratio, the maximum of the pressure wave is inverse proportional to the current pulse duration. The pressure wave increases with the increasing of the loading density. But the allowed electric energy ratio to control the pressure wave and the variation trend of the first negative amplitude wave value doesn't change. During the discharging of the DRPG, the influence of changing propellant web thickness in ETC launch can be ignored.