Analysis of Segmented Arc-Heater Flows with High Argon Concentration

Abstract

The existing computer code to solve the airflow in a segmented constrictor-type arc-heated wind tunnel named ARCFLO4 is improved to accept an air–argon mixture as the working gas. 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 and the results of the calculations made by Sakai using a similar code developed earlier, ARCFLO3.