Numerical Simulation on Decaying Arcs in Molecular Gas Flow including C, F and O

The present report describes numerical thermofluid simulation results on decaying arcs in molecular gas flow including C, F and O in a nozzle space on the assumption of local thermodynamic equilibrium condition. We here focused on C
2
F
6
gas, which was used in a form of gas mixture CO
2
/C
2
F
6
. In addition, gas mixture of CO
2
/O
2
/C
5
F
10
O, one of SF
6
alternative gas candidates, was also investigated. Their thermodynamic and transport properties were computed with collision integrals between species considered. Using these properties, the arc temperature and arc resistances were calculated by numerical thermofluid simulation for a free recovery condition from DC 50 A to 0 A for a fundamental study. The results showed that the arc temperature decay in 80%CO
2
/20%C
2
F
6
gas mixture was similar to that in 75%CO
2
/10%O
2
/15%C
5
F
10
O gas mixture.