Dielectric recovery of an axially blown SF6-Arc after current zero: part II-theoretical investigations

A three-dimensional (r,z,t) numerical model for the decay of the hot-gas channel after current zero is developed by transforming the differential equations for mass, momentum, and energy conservation into isotherms. The relative importance of the various parameters which govern the temperature recovery is evaluated with the aid of a systematic sensitivity analysis. Turbulence, especialiy in the region around the stagnation point, is shown to dominate the recovery behavior. Deviations from local thermal equilibrium are also shown to affect the shape of the recovery curve. The influence of various external parameters, such as the geometry, is also investigated.