Computational prediction of NASA langley HYMETS arc jet flow with KATS

Atmospheric entry occurs at very high velocities which makes the physics of the flow complicated to predict. Although high enthalpy flow facilities such as arc jets and plasma wind tunnels are widely used to examine the entry flow conditions, they can involve assumptions which make unrealistic predictions. High-fidelity modeling tools are essential for accurate predictions of the physical phenomena that occur during planetary entry as well as to better interpret ground testing. The Kentucky Aerothermodynamic and Thermal-response System - Fluid Dynamics (KATS-FD) is a research tool developed mainly to predict planetary entry conditions. In order to better understand and interpret the physics of an arc jet flow, KATS-FD is used and compared to a set of experimental data. The latter is provided by NASA Langley Hypersonic Material Environment Testing System (HYMETS) arc jet facility. From the array of experiments a test case was selected which consisted of a 6.5 MJ/kg enthalpy flow that discharged into a vacuum chamber at 0.228 kPa. The simulation parameters are compared to radial and axial velocity profiles measured using Planar Laser Induced Fluorescence (PLIF). Surface pressure and heat flux profiles are analyzed. The species concentration along the centerline is computed and presented. A parametric study of the nozzle wall boundary conditions and variation of bulk enthalpy is carried out in order to better assess the ground testing and numerical results.