Internal ballistic simulation and optimum design of gas-fired rodless cylinder ejection device

Abstract

Abstract A kind of gas-fired rodless cylinder ejection device which is stoke and weight controlled and suitable for mobile launch was designed. The leakage test of the ejection device is carried out based on the principle prototype of rodless cylinder ejection device and the empirical formula between leakage rate and pressure and travel length was fitted. The mathematical model of gas-fired rodless cylinder ejector internal ballistic with considering the leakage rate is established based on the assumption of zero-dimensional internal ballistic. When comparing the results of internal ballistics considering and not considering the leakage rate, it can be seen that the influence of leakage rate on the results of internal ballistics can not be ignored. The internal ballistic model which coupled the leakage rate is optimized, taking the shortest design stroke and smallest ejection stability index as design target and the parameters of the grain are used as design variables. The results show that after the optimization, the mass flow rate of gas at the end of ejection is increased by 19%, the stroke required for piston speed reaching the design target is shortened by 13.1%, and the launch stability index is increased by 10.7%.