Role of Induced Fields in Railguns
Paul J Cote, Mark A. Johnson, and Krystyna Truszkowska
Benet Laboratories, US Army Research Engineering and Development Command
We provide an analysis of the nature of EMFs induced during the operation of a railgun. The focus here is on railguns, but the results are applicable to a broad range of similar distributed parameter problems.
The main sources of induced EMFs are current changes and armature motion. It is shown, for example, that there is no true motional EMF in railguns, and an alternative approach is offered in terms of localized flux creation.
COMSOL Multiphysics modeling is used to illustrate the main concepts and consequences of induced EMFs, and to validate the analyses. Experimental data also provide added validation. The results offer insights into previously unexplained phenomena commonly observed in railgun tests.