Flow near the upstream electrode of gas-blast circuit breakers

A numerical method for incompressible, axisymmetric flow computations has been used to investigate flows through passages typical of those in gas-blast circuit breakers near the upstream electrode. Flow separation from the electrode is allowed for when the point of separation is known. Compressibility is approximately allowed for, to make comparisons with experimental results, and the agreement shows that an improvement over the one-dimensional flow calculation is achieved. The influence of the nozzle on flow over the shoulder of the electrode and on the point of flow separation appears to be an important factor in the performance of a circuit breaker.