Investigation of Separated Injection of Air and Argon in Segmented Constrictor Type Arc Heaters

세그먼트 아크히터 내부에서 공기와 아르곤 기체의 혼합 현상에 대한 연구

The existing computer code to solve the air flow in a segmented constrictor-type arc-heated wind tunnel named ARCFLO4 is improved to accept an air-argon mixture as the working gas and to consider the separated injection of air and argon. The new version of the code is used to calculate the flows in the Aerodynamic Heating Facility of NASA Ames Research Center where argon concentration is relatively high. The calculation shows that argon tends to increase the diameter of the arc-column, increase ionization fraction, decrease thermal efficiency of the arc-heater, and push the ratio of the centerline-to-average enthalpy toward unity. The calculated operating characteristics of the arc-heater agree well with the experimental data.