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The models of thermal conductivity in fibrous spatially reinforced medium were developed at overall anisotropy of components; the approach is based on equality between dissipation in equivalent material and  the considered composite. The calculated values of effective coefficients of thermal conductivity for two cases (unidirectional and cross-loaded) composites were compared with experimental data. Agreement between calculated and experimental data is satisfactory. It was demonstrated that developed models give the upper and lower estimates for effective coefficients of thermal conductivity in fibrous compositions.

Numerical computations of the electric-arc heating and anode melting were carried out within the framework of the two-dimensional unsteady mathematical model. The influence of the viscous interaction "plasma−melt", surface tension forces, electromagnetic forces, and gravitational convection on the formation of the hydrodynamics of the anode melt was considered.

The exact solution of boundary layer equations for laminar convective torch from point source of heat in fluid with power dependence of density on temperature was found.

On January 30, 2012 Sergey V. Stankus, the prominent scientist working in the area of thermophysics, Doctor of Physics and Mathematics  and  Deputy Director of the Institute of Thermophysics, became 60 years of age.

This paper presents results of a study of vortex wake structures and measurements of instantaneous 3D velocity fields downstream of a triblade turbine model. Two operation modes of flow around the rotor with different tip speed ratios were tested. Initially the wake structures were visualized and subsequently quanti-tative data were recorded through velocity field restoration from particle tracks using a stereo PIV system.
The study supplied flow diagnostics and recovered the instantaneous 3D velocity fields in the longitudinal cross section behind a tribladed rotor at different values of tip speed ratio. This set of data provided a basis for testing and validating assumptions and hypothesis regarding classical theories of rotors.

The influence of the vibrational relaxation on suppression of the Kelvin-Helmholtz instability in an evolving shear layer of a vibrationally nonequilibrium diatomic gas is studied numerically on the basis of equations of two-temperature aerohydrodynamics. Planar waves with the maximum growth rates, which were computed within the framework of a linearized system of equations of inviscid two-temperature gas dynamics, are used as the initial disturbances. It is shown that relaxation of the nonequilibrium vibrational mode at excitation levels, which can be obtained in diatomic gases in nozzle flows, in underexpanded jets, or in flows with moderate laser pumping, is accompanied by noticeable suppression of vortex disturbances. The associated relative enhancement of dissipation of kinetic energy of a large vortex structure averaged over its lifetime reaches approximately 13 %.

The analytic solution (in the form of the Neumann series) has been derived for the problem of computing the heat flux in a planar channel in the presence of a pressure gradient parallel with the walls (in the problem of planar Poiseuille flow) within the framework of the kinetic approach for arbitrary values of the Prandtl number. The ellipsoidal-statistical model of the Boltzmann kinetic equation is used as the governing equation, and the model of diffuse reflection is used as the boundary condition. The conducted numerical analysis of final expressions obtained in the present work showed a substantial dependence of the heat flux on the value of the Prandtl number of gas for channels whose thickness is comparable with the mean free path of gas molecules.

Results of an experimental study of the effect of flat mesh screens on the wave drag of a cylinder with flat face longitudinally streamlined with supersonic airflow at Mach number М = 4.85 are reported. Data on reducing the drag by meshes of various geometries and transparencies installed ahead of the cylinder face were obtained. Weighing and pneumometric measurements, and also PIV measurements of the vector velocity field, are reported. The flow pattern in the vicinity of the cylinder/screen system is visualized. It is shown possible to achieve a substantial (up to 45 %) reduction of the wave drag of the cylinder with a mesh screen. A physical interpretation to the wave-drag reduction phenomenon is given.

The interaction of disturbances in a boundary layer of the compressible gas is considered in the linear and nonlinear approximation (the weakly nonlinear theory of stability) in the presence of mass exchange (gas blowing or suction) on the surface. The regimes of moderate (the Mach number М = 2) and high (М = 5.35) supersonic velocities of the flow are considered. The suction from the surface is shown to lead to a considerable variation of the linear evolution of disturbances: the vortex disturbances of the first mode and the acoustic disturbances of the second mode are stabilized, the rate of variation is determined by suction intensity. The nonlinear interactions in three-wave systems between the vortex waves in asymmetric triplets at М = 2 and between the waves of different nature (acoustic and vortex waves) ⎯ in the symmetric ones at М = 5.35 are considered. The planar acoustic wave is the excitation wave in the latter, which excites the three-dimensional subharmonic components of the vortex nature. It is shown that one can delay considerably the transition region with the aid of suction, thereby one can reduce the skin-friction drag. In the gas blowing regime, strong deformations of the mean fields of boundary layers occur, which lead to the destabilization of the vortex and acoustic waves in the linear region and activate the nonlinear processes in transition region. One can expect that this will lead to the acceleration of tripping in supersonic flow.

Impingement of supersonic jet upon substrate surface, in front of which conical separation zone is created artificially with the aid of a spike or particle under conditions typical of cold spraying on geometric and dynamic parameters, is considered. Numerical simulation is carried out. Simulation results are in qualitative agreement with experimental observation data. Preliminary analysis of obtained pattern of supersonic jet impingement shows that in local ring area, creation of more favorable conditions for cold spraying of fine particles sized 1 micron or less is possible comparing to typical conditions.