One Kind of Approximate Field Scaling Relations in Railguns for Linearly Scaling Launcher Geometry

It is important to choose the appropriate railgun scaling method to extrapolate research findings from subscale to full scale. Aiming at the partial shortcomings of existing field scaling method, this paper proposed one kind of approximate field scaling relations for matching projectile velocity under the condition of linear geometric scaling and identical materials. Analytical derivation and numerical simulations were conducted to assess the similarities of projectile velocity and physical fields. The results show that projectile velocity can be matched approximately according to the scaling method, while the physical fields cannot be matched well. But the general values of the physical fields of full-scale launcher are lower than or approximately equal to the subscale launcher. Consequently, the launching condition of the full-scale railgun can be better than that of the subscale when designing and constructing with the approximate scaling method.