Simulation of Liquid Lubricant Injection in Electromagnetic Launcher Armatures

It has been suggested that an external electrically conducting liquid be introduced into the armature-rail interface of an electromagnetic launcher in order to suppress the velocity skin effect and delay the transition to arcing. In the present study, the liquid is introduced by injection from the armature. Since previous studies of liquid flow in the interface have shown that, depending on operating conditions, regions of reverse flow can be formed, it is not clear at what locations the liquid should be injected, or even if such injection can be effective. This paper seeks to answer these questions. The flow field produced by injection is simulated through the solution of a generalized 1-D Reynolds equation, taking into account the Lorentz force, the surface roughness of the armature and the rail, and the liquid injection. Two interface geometries, as well as a variety of injection locations and injection rates, are investigated