Field-Circuit Coupling and Electromagnetic–Thermal–Mechanical Coupling Analysis of the Single-Stage Fast Linear Transformer Driver Using Time-Domain Finite Integration Technique

The aim of this contribution is the first numerical investigation on the electromagnetic (EM), thermal, and mechanical coupled fields of a newly developed single-stage fast linear transformer driver (FLTD) with 24-separate columns in the China Z-pinch driver CZ34. Considering the mutual influences of the EM, thermal, and mechanical fields during a pulsed current discharging process of the FLTD, the proposed numerical model is calculated using the field-circuit coupled time-domain finite integration technique (TD-FIT). By making reference to Tonti's classification diagram, integral form state variables in the transient thermal field and mechanical field can be defined similar to those of the EM field. With appropriate time integration schemes, governing equations of different physical fields can be transformed to corresponding algebraic time-updating equations. The two-way interplays of the EM, thermal, and mechanical fields are performed with predefined coupling terms and time steps. The simulated results indicate that during one current discharging process, the temperature rise is less than 1 K and the maximum deformation generated by the Lorentz force is less than 0.1 mm.