PROJECT TITLE :

Physical Principle and Relevant Restraining Methods About Velocity Skin Effect

ABSTRACT:

Velocity skin impact (VSE) may be a reasonably current clustering phenomenon, which occurs at the sliding contact interfaces between the high-speed armature and the stationary rails of electromagnetic railgun launchers. Serious current clustering is disadvantageous to the launching performance. The everyday current clustering phenomena in static conductors are classified, and also the physical principle of VSE is analyzed during this paper. The physical principle in rails is just skin impact as a result of of the short rise time of the accepted pulse current, and therefore the physical principles in armature are clustering near tiny supply and clustering along short path of steady current attributable to the continuity characteristic or Laplace equation. The corresponding ways to restrain VSE are deduced and classified as follows: one) lengthening the contact surface; 2) adding a onerous and resistive cladding on the rail’s sliding surface; 3) narrowing the interface; 4) adopting a U-formed armature instead of cuboid one; and five) controlling the armature legs’ thickness/width distribution. Identical 3D model for VSE is adopted, and simulation is carried out for a complex kind of armature leg. The uniform current within the interfaces is accomplished, with which the everyday uniform index is regarding 66%. VSE is restrained in keeping with the simulation result. The physical principle, the relevant restraining strategies, and the equivalent model are important to railgun analysis work.