Studies on Fluid-Plasma Interaction Associated with Basic Gas Blast Characteristics based on a High-Order LES Turbulence Model

Abstract

In reducing the operating energy thermal puffer type gas circuit breaker is very advantageous. However a detail understanding of the basic fluid-plasma interaction phenomena associated with the gas blast characteristics is very much necessary for its efficient design. Therefore the main aim of this research is to study the basic fluid-plasma interaction phenomena based on a High-Order LES (Large Eddy Simulation) turbulence model. The model configuration used in this regard is a converging-diverging type nozzle installed with an anode and a cathode inside to generate thermal arc plasma in the nozzle flow field. Here, the basic physics associated with the reduction of arc diameter due to interaction of supersonic cooler gas with the thermally expanded hot core gas and related heat transfer through turbulent mixing is discussed. The results revealed that as more and more denser cooler gas entrain to the low density hotter core gas the arc region starts growing axially downstream the region of reduced arc diameter. However near the shock location in the nozzle an abrupt change in temperature distribution is observed.

The LTE Thermofluid Simulation of Ar/SF₆ Gas-Blast Arcs in a Nozzle Space in an Arc Device

“…(4) The arc plasma is optically thin. (5) The phenomena on the electrode surface such as electron emission, ion bombardment are neglected. (6) The electric field has only axial direction component.…”