Design Improvements in Multi-sectional HFCG using Time-varying Skin Depth

Abstract

Abstract Two-dimensional (2D) modelling procedure uses a filamentary-mesh approach and the dynamic matrix concept which are used in Helical Flux Compression Generator (HFCG) design. Although 2D modelling offer results which have been verified experimentally, yet none of the existing 2D-codes include the effect on skin depth that are caused from the high variation of current in very short duration of time. In most published codes, the formula that is used, provides simply a steady-state approximation of the skin depth. The influence of skin depth is represented approximately by using a static expression where frequency is assumed constant. This paper describes a new tactic by using a dynamic time-varying expression for skin depth, which is implemented for use with an existing 2D model. It is shown that effect of high change in current on skin effect is significant than those predicted by the constant skin depth formula.