Transient 3-d Simulation of an Experimental Railgun using Finite Element Methods

Abstract

Railguns have the capability to accelerate
projectiles to velocities in excess of 2 km/s. Current railgun
research is usually performed experimentally with support
from simulations. The finite element method (FEM) is a
wide spread tool in many fields of research and develop-
ment. But the transient computation of a 3-d model of a
railgun using FEM methods, taking into account the time
evolution of the acceleration process and the coupling of
the electromagnetic fields to the moving projectile, is a
complex task. Such a simulation involves large gradients
of the electromagnetic fields, large structures of the order
of meters with areas of interest in the sub-millimeter range
and a fast moving projectile causing a rapid change of the
current flow through the volume in the next vicinity of
the contact. Nevertheless, recent developments in FEM
tools make it attractive to attempt such a simulation.
At the French-German Research Institute of Saint-Louis
the electromagnetic acceleration group uses the program
C OMSOL for a transient 3-d simulation of a small caliber
railgun. This article presents the implementation of the
railgun as C OMSOL model and compares simulation results
to experimental data.