Calculation of railgun inductance gradient by 2-D finite element method

Inductance gradient has great influence on the performance of railgun. This paper deduced armaturepsilas force formulation, explained inductance gradientpsilas physical meaning, introduced the governing equation of 2-D time harmonic electromagnetic field, built railgunpsilas 2-D finite element model; a common structure railgunpsilas inductance gradient is calculated. The influence of time harmonic frequency and railpsilas dimensions on inductance gradient is investigated; distribution of rail current and spatial energy under varied influencing factors is displayed. The suggested method is verified by comparing the results with those in reference. According to the analysis results, optimal design of railgun is suggested.