3-D numerical simulation of plasma armature railguns

In this paper an equivalent network model for the three-dimensional analysis of a railgun plasma armature is presented. The plasma armature is decomposed in volume elements in which a uniform distribution of the current, momentum and heat flux densities is assumed. Then, three equivalent networks are derived. A first electric network is obtained for the determination of the current density and magnetic field distribution in the plasma arc; a second equivalent network allows the determination of the pressure and the mass density distribution and the internal motions in the plasma arc. The model was used in a previous work for the analysis of an isothermal plasma. In this paper the third equivalent network that is derived from the energy conservation and Saha equations has been used for the determination of the temperature distribution in the railgun plasma armature. Numerical simulations have been carried out assuming different boundary conditions for the radiative heat flux.