Theoretical Model and Analysis on the Locally Concentrated Current and Heat During Electromagnetic Propulsion

Electromagnetic propulsion technology has important applications in military equipment such as electromagnetic rail guns. The extremely harsh multiphysics environment during electromagnetic propulsion is the key problem that now restricts its practical application. Most previous modeling studies have neglected or set overidealized approximations for the coupling effects between different physics fields, resulting in large deviations between simulated and actual results. In this paper, the multi-field coupling dynamic model of the electromagnetic propulsion process is established. Based on this model, the dynamic changes of the armature's speed, current distribution and temperature distribution during the electromagnetic propulsion process are effectively simulated, and some characteristics of these distributions are different from the previous uncoupled model. Furthermore, the physical mechanism behind these special distribution features is revealed, and the significance of the nonideal factors such as the piezoresistive effect of contact resistance and friction effect of the contact interface on the electromagnetic propulsion are analyzed. Therefore, a feasible path for the simplification of the multiphysics model and the relief of the extreme environment is revealed, which will greatly promote the practical application of electromagnetic propulsion technology.