The application of Kiuttu´s formulation to study coaxial Flux Compression Generators

Summary form only given. A class of Flux Compression Generators (FCGs) is based on the compression of the cross sectional area of a coaxial geometry where the current flows along the outer conductor and returns through the inner conductor. This compression causes an increase in current. Kiuttu´s inductive electric field formulation is a powerful tool for the conceptual design of coaxial FCGs ¹. The usefulness of this formulation is demonstrated in this paper for a simplified geometry using a finite element partial differential equation solver, FLEXPDE ™, in calculation of the inductive electric field. A time varying applied current or a moving surface creates the nonconservative electric field. Losses due to diffusion of magnetic flux into conducting surfaces can also be accounted for and modeled in this setting. The computed electric field is then compared with the results obtained by a full-wave electromagnetics code; COMSOL™ MultiPhysics- and a comparison of the results will be reported. This analytical-computational approach serves as an important step in validating the MHD portion of the complex multi-physics parallel laboratory code, ALE3D. The non-intuitive boundary conditions involved in solving the otherwise straightforward partial differential equations are described in detail and illustrated in a simple model. The physical parameters used in the simulations are not based on a specific design^.