Energy Partition and Scaling Issues in a Railgun

We performed numerical simulations to characterize a conceptual naval railgun and to compute the spatial and temporal energy partitions among the kinetic, thermal, and magnetic energies. A numerical study was then undertaken to assess whether the energy partition, thermal, and kinematic characteristics can be examined through a subscale experiment. It turns out that not all field quantities can be consistently scaled, because the field equations involve both diffusion and wave equations. Three subscale cases-where displacement, velocity, and acceleration profiles were kept the same as the full-scale profiles-were considered. The velocity-matching scaling seems to provide the best case for subscale testing of thermal characteristics of a railgun. The results are expected to provide guidance for thermal management schemes and for suitable subscale tests