Capacitor-Driven Coil-Gun Scaling Relationships

Scaling method is an applied scientific method employed in experimental analysis. Also, in the analysis of an electromagnetic-launch system, the scaling method can be an aid in the conversion of test results from models to original. This paper focuses on the capacitor-driven coil-gun scaling relationships between the original and the model. The current-filament method is used to derive the scaling relationships of a capacitor-driven coil gun. If the input scale factors are chosen properly, output scale factors can be calculated by the scaling-relationship equations. Two single-stage coil guns were constructed and tested to verify the scaling method. The calculated scale factors agreed quite well with the test data. Further, three-stage coil guns were simulated based on Ansoft to verify the scaling method of the field results and changes in velocity with respect to the discharge position. It is shown that the scaling method is feasible. These laws allow, with proper application, the construction of experimental models in which phenomena similar to those occurring in the original are reproduced. The result can then be recalculated, using the scale factor for the physical quantity, into the original configuration. A detailed derivation and validation will be presented in this paper.