MHD-aspects of EML efficiency increase due to channel segmentation

It is known that one of the possible ways to increase the electromagnetic launcher (EML) efficiency is to segment the working channel. This paper presents the results of the theoretical investigation of the MHD-processes in a railgun channel for two types of segmented launchers: (A) segmented configuration where all segments are the independent railguns divided by inter-stage dielectric inserts, and (B) distributed configuration which has the nonsegmented rails and distributed energy sources. The operation of each stage of a segmented railgun is determined by intricate MHD-flows. The plasma flow interaction with the magnetic field is of complex character and has an ambiguous influence on the muzzle velocity. The character of the discharge behaviour was investigated for both schemes. The influence of the current shape, of augmentation, of section length and the optimization of the multistage railgun operation for these parameters were studied. It is shown that the energy input to the plasma armature by means of short fast current pulses reduces momentum losses and provides the considerable velocity increase.<>