Simulation of Thermal and Electric Fields in Electrodes with Allowance for Melting and Fritting of Films.

A mathematical model is formulated, and a finite-difference method and computer programs have been developed that allow effective computer simulation of the process of thermal breakdown of contact films. The system of equations includes the Stefan problem, the equations of electric transfer and of a switched circuit. The axial symmetry of the boundary-value problem conditions is assumed. A finite-difference method in a spherical coordinate system is used for the solution. During the development of the process, the radius of the conducting bridge made of a molten material changes by several orders of magnitude. An effective solution of this problem is the use of a "moving" grid by corresponding replacing the variables. The results of the work can be applied in the practice of research and design of electrical apparatuses and other electrotechnical devices. [ABSTRACT FROM AUTHOR]