Numerical study of the electrical arc movement supported by experiments

The aim of this study is the development of a numerical model for the prediction of the dynamic arc behaviour in low voltage switching devices. Due to the high thermal and mechanical stresses caused by the electric arc between the contacts of the switch the knowledge and prediction of the interactions between fluid dynamics and magnetic field is fundamental for the development of such devices. By means of a commercial finite volume code we solve the fluid dynamics problem and a commercial finite element code is used to solve Maxwell\'s equations. The two physical domains are coupled via a coupling interface which is responsible for the data exchange between the programms. Numerical investigations based on a parallel electrode configuration are presented and compared to experimental results. Depending on the current level we observe different arc movement behaviour, discontinuous and continuous movement, respectively, which is in fact an alternation from arc root dominated behaviour to electro-dynamically minated behaviour. Considering these phenomena the numerical and experimental results are compared and show good agreement for the arc voltage and for the arc movement.