Force on a coil moving above a grid structure

The lift and drag forces on a coil moving above a plane periodic grid structure are analyzed, with particular reference made to transport system applications for large space structures. The coil is approximated by two parallel wires moving parallel to the grid tubes; the corresponding two-dimensional electrodynamic problem is solved using expansions in terms of Bessel functions. Expressions are derived for the lift and drag force as well as the heat generated in the tubes in the limit of strong skin effect. The varying magnetic flux threading the coil is considered, and the thermal load of the coil is estimated.