Two-dimensional electrothermal modelling of multi-fibre solid brush armatures
conference paper
To simulate the electrothermal behaviour of multi-fibre solid brush armatures during electromagnetic launch in a square-bore dipole rail accelerator, a two-dimensional finite element computer code, which solves the magnetic and thermal diffusion equations, is being modified. The electrical properties of these armatures are modelled with a tensorial specific resistivity which accounts for the mutual insulation of the fibres. Results for the diffusion of the magnetic field into a conducting rectangular copper multi-fibre solid brush armature are compared with the results obtained with an analytical method. The performance of rectangular and U-shaped multi-fibre solid brush armatures made of copper, aluminium and molybdenum is analysed. In these simulations, a breech current profile typical for the electromagnetic launch experiments performed at the TNO PMI.rPulse Physics Laboratory, is used. The influence of thermal insulation of the fibres and of the loss of electrical insulation of the fibres at higher temperatures on the elecrrothermal behaviour of the armatures is considered. Recommendations on the choice of armature material and geometry are given in order to achieve the optimum current distribution in the armature during electromagnetic launch.
Topics
TNO Identifier
122021
Article nr.
P301
Source title
4th European Symposium on Electromagnetic Launch Technology, Celle, Germany, 2-6 May 1993
Collation
10 p.
Files
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