Simulation of ablation arcs in realistic nozzles

Self-consistent modelling of arcs in circuit breakers is very valuable since it does not require any empirical input and thus enables simulations of arcs with arbitrary shapes and arcing modes. A self-consistent CFD arc model with physically sound radiation description is developed and applied in this work to simulate ablation controlled arcs in cylindrical and non-cylindrical nozzles. The impact of the nozzle shape on the arc pressure and voltage is shown. The model is validated by comparisons to experimental data for cylindrical nozzles and an industrial high voltage circuit breaker. The model is capable of predicting the measured quantities with less then 20% error.