Numerical Investigations on the Pressure Wave Absorption and the Gas Cooling Interacting in a Porous Filter, During an Internal arc Fault in a Medium-Voltage Cell

A mathematical model and a numerical method have been developed to simulate the mechanical and the thermal physical phenomena in a energy absorber like a porous filter, during an internal arc fault in a medium-voltage apparatus. A 1D gas flow model in porous medium with variable porosity is described. The main point is the introduction of a new numerical scheme to take accurately into account discontinuous variations of the porosity and correctly simulate the creation of the transmitted and reflected waves. Numerical simulations are compared to experimental measurements performed on apparatus specially adapted for tests to provide a better understanding of the physical phenomena involved, for instance, the gas cooling and the shock wave absorption by the porous medium of the filter.