Kucherov A.N.,Zhukovsky Central Institute of Aerohydrodynamics
Technical Physics | Year: 2011
The effect of circulation in the field of a bulk vortex source on thermal crisis (flow choking induced by energy supply in a layer in accordance with a known law) is studied. Substantial changes in the value of energy supply parameter and slight variations in the coordinate of the critical cross section in which the velocity of sound is attained are revealed, and the dependence of these parameters on the location and width of the heat-supply region is noted. The possibility of transition to a supersonic flow when the heat release region is near the minimal cross section of the vortex source is analyzed. The difference between the cases of polyatomic and monatomic gases is demonstrated. Distinguishing features of the vortex sink are considered. © 2011 Pleiades Publishing, Ltd.
Lebed' I.V.,Zhukovsky Central Institute of Aerohydrodynamics
Russian Journal of Physical Chemistry B | Year: 2014
Multimoment hydrodynamics equations are used to solve the problem of flow around a quiescent solid sphere. The solutions to the multimoment hydrodynamics equations are found, which enable to interpret of the phenomenon of vortex shedding. The solutions give a pattern of instability development that qualitatively reproduces experimental data over a wide range of Reynolds numbers. The replacement of one unstable flow mode by another unstable mode is governed the tendency of the system to find the fastest way to depart from the state of statistical equilibrium. After stability loss, the system does not reach a new stable state. Such a scenario is at odds with the ideas of classical hydrodynamics, which interprets the development of instability in terms of a bifurcation transition from one stable state to another. This picture presented shows the direction of solving the problems faced by classical hydrodynamics in the interpretation of the phenomenon of vortex shedding. © 2014 Pleiades Publishing, Ltd.
Kravtsov A.N.,Zhukovsky Central Institute of Aerohydrodynamics |
Mel'nichuk T.Yu.,Zhukovsky Central Institute of Aerohydrodynamics
Russian Journal of Physical Chemistry B | Year: 2011
The parameters of a conical stabilizer and its effect on the aerodynamic characteristics of the highspeed air vehicle, in general, are examined. The flow characteristics of an high-speed air vehicle with a conical stabilizing device are analyzed. Simulation results are compared with experimental data. Qualitative features of the supersonic flow associated with the characteristics of the drag of an aerodynamic configuration with a stabilizing device in the form of a truncated cone are considered. Particular attention is paid to the physical aspects of the flow around the considered configurations and to elucidating the mechanisms responsible for a minimum in the drag coefficient of a wingless high-speed air vehicle. A general mechanism of occurrence of the minimum in the drag coefficient for aerodynamic configurations with a conical tail stabilizer is studied. © Pleiades Publishing, Ltd., 2011.
Geliev A.V.,Zhukovsky Central Institute of Aerohydrodynamics |
Do Kh.D.,Moscow Institute of Physics and Technology |
Egorov B.V.,Moscow Institute of Physics and Technology |
Markachev Yu.E.,Zhukovsky Central Institute of Aerohydrodynamics |
And 3 more authors.
Russian Journal of Physical Chemistry B | Year: 2011
The correlation dependence of the critical Reynolds number of the laminar-turbulent transition on the equilibrium constant of dimerization in a gas during gas flow in dry or sprayed tubes is presented. A new approach to this problem is suggested related to the use of the quasi-chemical cluster gas model devel-oped by the authors. © 2011 Pleiades Publishing, Ltd.
Lebed' I.V.,Zhukovsky Central Institute of Aerohydrodynamics |
Umanskii S.Ya.,RAS Semenov Institute of Chemical Physics
Russian Journal of Physical Chemistry B | Year: 2012
Any of the infinite number of invariants of a binary collision of structureless particles was shown to annihilate the collision integral written in the 12-dimensional phase space of two particles. Its own principal hydrodynamic value corresponds to each of these invariants. The six-dimensional phase space of one particle can only accommodate three lower binary collision invariants that allow the integral of collisions to be annihilated. The first equation of the Bogolybov-Born-Green-Kirkwood-Yvon hierarchy is, however, not closed, and the transition from the 6-dimensional phase space to the hydrodynamic stage of description is therefore closed. The Boltzmann hypothesis closes the kinetic equation and therefore opens up the possibility of approximate transition to hydrodynamics. Just the Boltzmann hypothesis allows classic hydrodynamics equations constructed with the use of only three lower principal hydrodynamic values to be substantiated statistically. It should be expected that the neglect of the higher principal hydrodynamic values will limit the applicability range of classic hydrodynamics to states insignificantly removed from the statistical equilibrium state. Most probably, just this limitation is responsible for obvious discrepancy between the results of direct numerical integration of the Navier-Stokes equation and the experimental data on flows that lost stability. The possibility of the improvement of classic hydrodynamics equations is sought on the way toward an increase in the number of principal hydrodynamic values. © 2012 Pleiades Publishing, Ltd.