Application of Planck-Rosseland-Gray Model for High-Enthalpy Arc Heaters

The existing ARCFLO computer code for numerically simulating the flow in the constrictor of a constricted-arc wind tunnel is upgraded by replacing the two-band gray-gas radiation model with the Planck-Rosseland-Gray model developed recently. The code is now applicable to both air and carbon dioxide flows. For the airflows thermochemical nonequilibrium is accounted for approximately in determining the thermodynamic variables. For the carbon dioxide flows condensation of solid carbon on the wall is accounted for. Turbulence parameters are adjusted to accommodate the change in the radiation model. For airflows the present modification reproduces the existing experimental data well. For carbon dioxide flows the present code predicts operating characteristics that are similar to those for airflows and a thin carbon deposit layer on the wall.