Experimental and Numerical Study of Nonequilibrium Ultraviolet NO and N Emission in Shock Layer

Abstract

The results on an investigation of nonequilibrium uv radiation in the systems of molecular bands NO and N 2 + (1-) in a shock layer in air are presented. The studies included the experiments on a measurement of the nonequilibrium radiation behind a strong shock wave in an electric arc-driven shock tube within the range of shock-wave velocity change V s =5 to 10 km/s at the initial air pressure P 1 = 0.1 torr, and numerical simulation of radiation processes behind the shock wave and in a hypersonic viscous shock layer, where the flow was simulated on the basis of Navier-Stokes equations. A numerical model of the radiation behind the strong shock wave has been used to verify a kinetic scheme of radiation processes by comparison with experimental results. Examples of emission calculations in the NO and N 2 + (1-) systems for the conditions of a flight test are presented