Study for the Efficiency of Combined Electro-Discharge Launcher

The experiments with combined launcher joined together the preliminary adiabatic compression of working gas by means of powder charge and its subsequent heating by the electric arc are continuing at the IEE RAS. This operation mode provides the high efficiency of launcher and allows to decrease required temperature and pressure of working gas. The results of combine launcher tests experiments are presented in the paper. It was studied the influence of initial experimental conditions on efficiency of acceleration. The main parameters of the experiments were varying in following range: initial pressure-10-15 MPa, pressure before the discharge -150-300 MPa, initial particle density (1.5- 3.3)times10²² cm^-3, maximum pulse pressure - up to 500 MPa, discharge current -300-700 kA, current rise rate dI/dt ~10¹⁰ A/s. It was defined that best results achieved when gas mass did not exceed the projectile mass. Obtained experimental data permit to build the dependence of acceleration efficiency on initial gas pressure and inputted electric energy. The optimization of working parameters of launcher from the point of view of energy balance was performed. It was shown that consumption of electric energy consists of 30 - 50 % in compare with classic electrodischarge launcher. In this paper the mass-velocity characteristics of combined launcher for the projectile of 1-16 g weight in velocity range 1.5-5.0 km/s are presented. The best ballistic results: velocity of 2.5 km/s for 7.5-g projectile and velocity of 4.9 km/s for 1.5-g projectile.