SCALAR-BASED FINITE-ELEMENT MODELING OF 3D EDDY CURRENTS IN THIN MOVING CONDUCTING SHEETS

A new set of formulations is presented for the 3D eddy current finite element analysis of thin moving conducting sheets. The conducting shee t, moving at a constant linear velocity in the direction of the sheet plane, is modelled using two scalar quantities, T and the normal compo nent of the magnetic flux density. The second scalar, B . n, is introd uced to maintain a second order partial differential equation system. Scalar potentials are used to model the nonconducting regions. This sc heme, implemented for time-harmonic cases, is compared with the more u sual A - psi method using a computer model, and force predictions agre e favourably. In the DC limit, it is possible to eliminate the T varia ble, thereby retaining only the B . n scalar in the sheet description. Two experimental test problems serve to illustrate drag and lift forc e predictions obtained using the two new schemes, T - B . n - psi and B . n - psi, and the more usual moving A - psi formulation.