Plenary Lecture
Stability of boundary layer of the chemical non-equilibrium gas
Professor Sergey A. Gaponov
Khristianovich Institute of Theoretical and Applied Mechanics (ITAM)
SB RAS, 630090, Novosibirsk
RUSSIA
E-mail: gaponov@itam.nsc.ru
Abstract: The purpose of the lecture is an analysis of the non-equilibrium dissociation influence on a stability of laminar boundary layer characteristics. Analysis is carried out for reactions going both on the wall (catalytic recombination) and within the boundary layer (gas-phase dissociation), when external flow is frozen. In it the basic equations and relation of dynamic gas mixtures are analyzed, stationary boundary layer equations are reduced. The overall setting of the sustainability of the boundary layer is chemically non-equilibrium gas includes the calculation of boundary layer; linear stability equations; conditions on the outer boundary layer edge and on the wall. At a derivation of boundary conditions the parameters defining influence of a catalytic recombination were revealed. On an example of diatomic gas an influence of catalytic recombination on a plate surface is discussed at moderate (low) Mach numbers and temperatures both without taking into account the gas-phase dissociation and at its account. In the first case it was possible to use simple model of gas and to carry out the parametrical calculations defining influence on stability of such factors, as degree of a dissociation of external flow, catalytic activity of a surface, a thermal emission at a recombination and equilibrium value of degree of the dissociation on a wall. In case of the gas-phase dissociation which is taking place at high Mach numbers and temperature drops in a boundary layer, its influence on stability characteristics is considered. The more exact analysis of physical and chemical gas properties is given for oxygen, nitrogen. The special attention is given to the analysis in the non-viscous approach which is effective at large Mach numbers. In addition to diatomic gases researches of stability of boundary layers more complex gas mixes are included in consideration.
Brief Biography of the Speaker: Sergey Gaponov graduated from the Physics Department of Novosibirsk State University, Russia in 1964. With 1965 till April he works in the Khristianovich Institute of Theoretical and Applied Mechanics of Siberian Branch of Russian Academy of Science as Junior and Senior Scientific Researcher, Head of Laboratory. Now he is Main researcher of the same Institute. With 1992 he works also as Professor of the Department of Theoretical Mechanics, Novosibirsk State University of Architecture and Civil Engineering. S. Gaponov is the expert in a field of the fluid and gas mechanics. The basic directions of his scientific activity are connected with researches of hydrodynamic stability, non-stationary processes and the turbulence occurrence in supersonic gas flows. He defended the candidate thesis "Stability of the incompressible boundary layer on a permeable Surface" (1971) and doctor thesis (physics and mathematics) “Development of disturbances in a supersonic boundary layer” (1987). He is member of Council on a defence of doctoral theses at Institute of Theoretical and Applied Mechanics, member of Russian National Committee on Theoretical and Applied Mechanics, member of the International Scientific Committee on Fluid Mechanics and Aerodynamics. The prize of Zhukovsky was awarded to him. There are many grants for fundamental research in which he took part: Grant of International Science and Technology Center: ISTC-128-96 investigator, Grants of Russian Foundation for Basic Research (team leader.) He took part in work of numerous scientific conferences, including the Fluid Mechanics and Aerodynamics conferences. Number of his papers in refereed journals is more than140. Two books were published.