Performance predictions for electromagnetic launching with multi-fibre solid brush armatures and resistively layered rail accelerators
conference paper
In the literature on EML research, a number of proposals have been made to suppress the negative influence of the velocity skin effect on the performance of solid armatures during electromagnetic launch. In this paper, the results of a study of two of these methods, i.e. the application of multi-fibre solid brush armatures and the use of accelerator rails with a resistive layer, are presented. This study is performed by means of two-dimensional finite element computer simulations of the electrothermal behaviour of the armature and the rails during the launch process. A description of the electrothermal model used in the simulations is given. Here, the fibre armatures are regarded as made of materials with an anisotropic electrical and thermal conductivity. The results for the current distribution in a rectangular multi-fibre solid brush armature obtained from the simulations agree with the results of an analytical method. It is shown that fibre armatures have a more homogeneous current distribution during the acceleration process than monobloc armatures. U-shaped molybdenum multi-fibre solid brush armatures are good candidates for arc erosion-free launching if the electrical insulation of the fibres can be maintained at increasing temperature. Simulations also show that the skin depth in monobloc and fibre armatures can be increased by using rails with a resistive layer with suitable material properties.
Topics
AccelerationComputer simulationElectric current distributionElectric insulationElectric windingsFinite element methodMaxwell equationsNumerical methodsParticle acceleratorsPerformanceSkin effectMulti fibre solid brush armaturesPerformance predictionsRail acceleratorsVelocity skin effectElectromagnetic launchersEM launching / Electromagnetic launchingVelocityComputerized simulationAcceleratorsArmatures
TNO Identifier
232833
ISSN
0018-9464
Publisher
IEEE
Article nr.
364617
Source title
IEEE Transactions on Magnetics Proceedings of the 7th Symposium on Electromagnetic Launch Technology, 20-24 April 1994, San Diego, CA, USA
Place of publication
Piscataway, NJ, United States
Pages
651-656
Files
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