A rail gun plasma armature model

A simple model is constructed for the plasma armature of a rail gun. We make the assumption that no gun tube ablation occurs, and then calculate the barrel inner wall heating when swept by the armature. The model thus provides operating parameters for which rail guns can be fired without melting or ablation. In this ablation-free domain, formulas for turbulent hydrodynamic flow in pipes can be used as a guideline for the heat flow from the turbulent plasma armature. This model is complementary to the Los Alamos ablative model of Parker et al. in which it was assumed that the energy dissipated in the armature arc is converted to ablated wall material which enters the arc.