Electromagnetic forces and powers in the secondary circuit of flat linear induction pumps with lateral busbars

S. V. Vasil'ev

Abstract
A solution of the equations of the electromagnetic field, obtained in a plane-parallel statement taking account of the exponential damping of the primary field and of magnetic conductivity in the field of the busbars, is used in an analysis of the distribution of the electromagnetic forces and of the Joule losses and to find expressions for the power transmitted to the secondary circuit. A numerical analysis of the theoretical relationships obtained is presented. It is noted that, with an expansion of the channel, when the bus bars are replaced by the liquid metal, the amount of power transmitted to the secondary circuit may rise considerably. Calculating curves are obtained which permit selecting the width of the layer of metal with which the electromagnetic pressure or the power transmitted with a given width of the inductor will be maximal. It is established that, with the presence of lateral busbars, the choice of their width must be made taking account of the effect of the currents induced in the busbars. An important role is played by the demagnetizing effect of the intrinsic currents of the busbars, which can lead to a decrease in the contribution of the bus bars to the pressure developed. The theoretical results were compared with experimental data obtained with measurement of the forces in metallic plates. Satisfactory agreement was obtained between the calculated and experimental values.