Multispecies Reacting Flow Model for the Plasma Efflux of an ETC igniter-Application to an Open-Air Plasma Jet Impining on an Instrumented Plate

摘要

The U.S. Army Research Laboratory (ARL) is investigating the electrothermal-chemical (ETC) gun concept. As part of this program. ARL has undertaken a comprehensive study on the interaction of the plasma efflux from an ETC igniter with solid propellant grains. The goal of this work is to elucidate the physical, mechanical, and chemical mechanisms that underlie the observed ballistic effects in ETC guns that lead to performance gains. This report describes the first phase of the modeling effort in support of this plasma- propellant interaction project. A time-accurate computational fluid dynamics code is used that includes high-temperature thermodynamic, variable specific heats and transport properties (viscosity and thermal conductivity). and finite- rate (nonequilibrium) chemical kinetics. Validation of this code uses a series of experiments with an ETC igniter fired into open air, generating an unsteady flowfield in which an instrumented plate is placed. Computer simulations reveal important gas dynamic and chemical details of the plasma jet as the jet mixes with air and interacts with the plate, representing a unique model of the ETC plasmas.