On Laminar-to-Turbulent Transition of Arc-Jet Flow in the NASA Panel Test Facility

摘要

This paper provides experimental evidence and supporting computational analysis to characterize the laminar-to-turbulent flow transition in a high-enthalpy arc-jet facility at NASA Ames Research Center. The arc-jet test data obtained in the 20 MW Panel Test Facility include measurements of surface pressure and heat flux on a water-cooled calibration plate and measurements of surface temperature on a tile plate with reaction-cured glass-coating. Computational fluid dynamics simulations are performed to characterize the arc-jet test environment and estimate its parameters consistent with the facility and calibration measurements. The present analysis is composed of simulations of the nonequilibrium flowfield in the facility nozzle, test box, and flowfield over test articles. Both laminar and turbulent simulations are performed, and the computed results are compared with the experimental measurements, including Stanton number dependence on Reynolds number. Comparisons of computed and measured surface heat fluxes (and temperatures), along with the accompanying analysis, confirm that the boundary layer in the Panel Test Facility flow is transitional at certain arc-heater conditions.