Effect of geometrical parameters on inductance gradient of multiple electromagnetic railguns

Inductance gradient is one of the important parameters on the design and evaluation of railgun performance. It influences the muzzle velocity and the system efficiency of a railgun, which is determined by gemometry, dimensions, materials and so on. Considering the eddy current loss, the 3D finite element method was used to analyze the effect of geometrical parameters on inductance gradient of multiple electromagnetic railguns. The 3D model was made up of three pairs or four pairs of railguns, the bore size was 40mm×15mm, the armature size was 30mm×30mm×30mm, the different inner rails of the three pairs of railguns were tangent to a circle, the different inner rails of the four pairs of railguns were tangent to a circle or parallel to two pairs. In this paper, the influence of the distance among diffent railgun, armature position on inductance gradient were discussed. According to the analysis results, optimal design of multiple electromagnetic railguns is suggested.