Thermal Computation in Railgun by Hybrid Time Domain Technique 3-D-FEM-IEM

Abstract

Thermal energy in railgun is unwanted and generated by ohmic losses that are dependent to the current implied, rail dimensions, electrical conductivity (sigma), and specific heat (C(P)). sigma and C(P) are functions of temperature. Using achievement L' formula by intelligent estimation method, the current density and ohmic losses on the cross section of the rail are computed. Ohmic losses are the source heat and utilized heat equation that are used to compute thermal distribution and temperature that are compared with other results in some papers. This paper chose h = 30 mm, w = 10 mm, and copper for the rail material and a method to compute the thermal distribution on the surface of the rail and side rail edges. Effects of rail dimensions on the temperature in time domain are calculated and shown in the figures. Rail materials are investigated with copper and aluminum in which the average temperature of both materials on the rail surface is calculated and compared.