The physics occurring during the operation of a circuit breaker isnvery complex. Numerical modelling must take in to account the changingngeometry during the operation, the fluid dynamics within the nozzle andnthe arc and the radiation transport within the arc. Because the flowncharacteristics of a puffer circuit breaker were not well known, it wasnnecessary to develop numerical and experimental techniques which couldnbe used to predict and measure the flow within a circuit breaker. Hence,na puffer circuit breaker was used to carry out a flow investigation andnthe results of this investigation were compared with the results of thennumerical analysis. The numerical analysis was based on the use of ancommercially available CFD package. The programme of work was divided innto two parts, the `cold flow' and the `hot flow' investigation. Thenfirst part involved the flow in the absence of an arc, the second partnwith the arc present. In the `hot flow' analysis the arc was firstnrepresented by a simple heat source and subsequently by a full arc model
展开▼
