| Abstract: | The hypersonic nonequilibrium rarefied gas flow is investigated in the neighborhood of the stagnation streamline ahead of a blunt body by taking into account nonequilibrium radiation due to electron excitation for air and carbon dioxide. The analysis is on the basis of a numerical solution of the Navier—Stokes equations simplified under the assumption of local self-similarity of the flow with the Shockwave structure taken into account. It is shown that at low densities, when the shock wave and shock layer thicknesses are of the same order of magnitudes, the two-layer Cheng model becomes inapplicable in the presence of radiation. In this case, the governing process is diffusion of the electronically excited molecules from the shock layer into the forward part of the shock front. The mechanism of the formation of a  second luminous plateau on the diagram of the nonequilibrium radiation intensity density is discussed. The combined influence of the limit in collisions and the diffusion transport processes on the intensity of molecular band radiation is considered.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 81–87, November–December, 1974.The author is grateful to V. V. Lunev for discussion and remarks during performance of the research. |
