Effects of Operating Condition on the 2-dimensional Temperature and Velocity Distributions of a Thermal Plasma Jet in a Segmented Arc Heater

Abstract

A segmented arc heater with an input power of 2.5 MW for thermal protection studies of a re-entry vehicle was numerically simulated to determine its appropriate operating conditions. A self-developed magnetohydrodynamics code was used to analyze the 2-dimensional characteristics of the thermal plasma jet in the segmented arc heater. Operating ranges of the air flow rate and the arc current were from 20 to 60 g/s and from 400 to 800 A, respectively. Although the velocity of the thermal plasma jet and the input power were increased by increasing the air flow rate, the plasma enthalpy, which is proportional to the temperature, was decreased at a high air flow rate because of the cooling effect. On the other hand, an increase in the arc current had the positive effect of increasing the plasma temperature. As a result, the target enthalpy of over than 20 MJ/kg was achieved for an air flow rate of 40 g/s and an arc current above 600 A.