Effect of rarefaction on a gas flow of reactive gas mixtures over a catalytic wall

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The flow of a reactive binary gas mixture over a catalytic plane wall is considered and the effect of rarefaction of the gas is investigated theoretically. The near-continuum equation as well as its boundary condition at the wall for small Knudsen numbers are obtained by applying the asymptotic expansion to a model equation of the Boltzmann equation. The results show that the diffusion velocity normal to the wall depends only on the reaction rate at the wall and that the slip coefficients of velocity and temperature vary considerably with the rate of the compositions. The high speed flow between two plates (Couette flow) was investigated using the equations and the boundary conditions obtained to clarify the effect of rarefaction on the heat transfer and flow. The similar calculation was made of the ternary mixture over a catalytic wall. It is shown that the jump of the temperature at the wall varies with the concentration ratio of the components and may have a positive or negative val … More ue according to the ratio.The slip condition of vibrational temperature is derived from the vibrational energy balance at the egde of the Knudsen layr for multi-component gas. The condition is applied to the analysis of the nonequilibrium viscous shock layr of a hypersonic vehicle.The free molecular flow of two component gas mixtures through a circular tube from a reservoir to a vacuum is analyzed theoretically to investigate the flux and reaction rate dependence on the tube length. the tube wall is catalytic and hence the reaction of gas mixtures proceeds to make the third species. The rate of product is shown to be almost independent on the tube length if it is aboutt two times as large as the tube radius.The Couette flow of a rarefied gas is analyzed with the boundary condition in which the gas-wall interaction is treated by the molecular dynamics method. The result shows the big deviation with the diffuse reflection boundary condition especially for large Knudsen number.The flow through a circular tube of high wall temperature is investigated experimentally to know the flux dependence on the Knudsen number. It is shown that the conductance decreases with increasing the temperature. Less