Plasma behavior in the boundary layer near a railgun surface

Viscous flow and thermal characteristics are theoretically analyzed for the plasma behind a moving projectile inside a railgun. When only convective effects are included in the turbulent boundary layer analysis, the results suggest a temperature maximum in the wall region for very-high-velocity flow. The case of radiative as well as convective transport has also been investigated for an optically thick boundary layer flow by application of an approximate method. Results show a sizable effect of radiation on the flow characteristics, especially on the heat transfer rate to the railgun surface. Specifically, the theory predicts that the heat flux to the wall is proportional to the square root of the sum of the radiation and convection parameters