Experimental validation of a capacitor discharge induction launcher model

A recoilless electromagnetic launcher for model validation

“…The arrangement of figure 1 (a) has been successful in producing results in reasonable accuracy with model predictions [7], provided that the launch energy is kept low. The reduction in accuracy that occurred as the energy was increased was attributed to either transient changes in the power supply parameters, recoil movement of the drive coil or crushing of the projectile by an inwards directed radial force.…”

“…The drive coil is fed from a capacitor bank through a closing switch and a transmission line, with a crowbar switch sometimes used to short circuit the coil and so maintain a unidirectional flow of current. In one typical example [4], the 40-turn drive coil had 8 layers and was wound from 5 × 1 mm copper strip, with the 20 mm long aluminium projectiles having an outside diameter of 100 mm and a wall thickness of either 3 mm or 5 mm. The power supply for the coil was provided by a single 113 µF capacitor, switched to the coil and crowbarred by means of ignitrons.…”

“…Steady-state ac simulations at a frequency close to the ringing frequency of the normal capacitor discharge gave a useful indication of the distributions of the magnetic field and the eddy-currents in both the launch coil and the projectile. The performance of the launcher with a moving projectile was modelled using a well proven filamentary model [7].…”

“…Filamentary models [1][2][3][4] form an excellent theoretical basis for simulating the performance of electromagnetic launchers, and in due course they may even lead to a unified model that includes the deformation occurring in both the projectile and the drive coil during the launch cycle [5]. To date however, accurate experimental validation of the theoretical predictions provided by existing models has only been obtained at low energy levels, with the discrepancies for a given launcher increasing significantly with the energy level [6].…”

Numerical Modelling of a Flyer Plate Electromagnetic Accelerator

“…A number of original features have recently been introduced into the standard approach (also termed network mesh or meshmatrix method), mostly related to the fast dynamics of imploding/exploding metallic structures. The technique has been successfully applied by Loughborough along the years in a very wide range of pulsed power applications, including pulsed ultrahigh magnetic field coils [12], explosively driven fluxcompression generators [13], [14], single and multiturn electromagnetic launchers [15]- [17], electromagnetic launchers [15]- [17], electromagnetic compression [18], and the design of various types of high-voltage air core pulsed transformers [19].…”