Block diagram model for the simulation of an electromagnetic rail accelerator system

Abstract

Rail accelerators are superior to classical gas driven accelerators with regard to attainable terminal velocity, ignition delay variation, and controllability and, therefore, have received a growing scientific interest in the recent past. The behavior of such a launcher is generally described with a system of nonlinear differential equations, which can be solved in many ways. This is done in order to describe an existing launcher, to predict its performance when parameters change, or to estimate the properties of such a system in the design phase. This paper presents a simplified electro-mechanical system of differential equations in a novel form. This form enables scientists and engineers to solve the equations using the software Scilab, Matlab or a similar one. The model is robust and parameter changes have a low impact on the solving time. This makes it a reliable tool for parametric studies. The model comprises the pulsed power capacitors, the pulse forming network, cables and the launcher itself. At first, the electrical part is described with its circuit equivalent and coupled with the mechanical process. Secondly, the system is analytically transposed to a standard form. This form is then transferred into the simulation software, which solves the equations. It can be simply adapted to other launchers and modified to comprise nonlinear side effects. The simulation results are compared to experimental results from the augmented rail accelerator at the French-German Research Institute Saint-Louis, France. A comparison between simulation results and experimental measurements shows a good agreement, whereas the model is still kept simple.