2-D viscous magnetohydrodynamics simulation of plasma armatures with the CE/SE method

A possible two-dimensional viscous magnetohydrodynamics (MHD) model is applied to investigating the plasma armature in a railgun. The space-time conservation element and solution element (CE/SE) method for solving the coupled Navier-Stokes equations and Maxwell equations was devised. The distributions of physical parameters of the plasma may thus be evaluated. The results show that extremely high pressure can always be observed ahead of the projectile, and the Lorentz force is the main propulsion. The distribution of temperature is in a good agreement with the results predicted by the law of radiation at the boundaries. Due to convection, the circulation patterns of velocity are evident in both the cases considering inviscid and viscous effect. Furthermore, the velocity and acceleration oscillate over time until a new steady state is achieved. This model efficiently captures the salient features of the physical phenomena, and contributes to further studies of MHD problems in plasma armature. Supported by the National Natural Science Foundation of China (Grant No. 10672080)