DETERMINATION OF MATERIAL CATALYCITY AT HIGH TEMPERATURES IN THE VAT-104 HYPERSONIC WIND TUNNEL

Abstract

Nitrogen and airflows in a duct of the VAT-104 high-temperature wind tunnel are modeled by means of the numerical solution to the unsteady two-dimensional Navier−Stokes equations in wide ranges of the total pressure (1−40 kPa) and stagnation temperature (5500−8000 K). Parametric numerical studies of nonequilibrium heat transfer on the end face of a thermally insulated circular cylinder at different cylinder surface catalycity values are performed. For each flow regime, the dependence of the surface temperature on the heterogeneous recombination rate constant Kw is obtained and the derivative α = dTw /dKw is determined. The catalycity of the C−SiC thermoprotective material in nitrogen and air plasma flows at surface temperatures of Tw = 1500−1900 K is determined in the calculations and experiments based on the measured temperature differences of the reference and examined materials.