Development and application of thermodynamic charts for nonequilibrium plasma flow in a supersonic nozzle

摘要

Owing to the uncertainty and difficulties in the determination of ionization and recombination rates, calculations of plasma flows through supersonic nozzles are very involved and often inaccurate. LChE (local chemical equilibrium) and frozen flow assumptions are frequently employed for an estimate of the ranges of nozzle performance and property variations along the nozzle. However, most of previous equilibrium and frozen flow analyses for reacting flow estiamtion were carried out for a single entropy value which are not applicable to transition processes between equilibrium and frozen flows with finite reaction rates. The entropy of a reacting flow increases when chemical reactions with finite reaction rates occur and the final state of the plasma may fall outside the bounds of equilibrium and frozen flow solutions determined at the reservoir entropy.