Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia



Advanced Search

Thermophysics and Aeromechanics

2009 year, number 3

1.
Application of "POLIS" PIV system for measurement of velocity fields in a supersonic flow of the wind tunnels

Y.K. Akhmetbekov1, A.V. Bilsky2, D.M. Markovich3, A.A. Maslov4, P.A. Polivanov5, I.S. Tsyryul'nikov6, M.I. Yaroslavtsev7
1 Kutateladze Institute of Thermophysics SB RAS Novosibirsk State University
2 Kutateladze Institute of Thermophysics SB RAS
3 Kutateladze Institute of Thermophysics SB RAS Novosibirsk State University
4 Novosibirsk State University Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
5 Novosibirsk State University Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
6 Novosibirsk State University Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
7 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: supersonic flows, velocity field measurement, particle image velocimetry
Pages: 342-352

Abstract >>
Measurement results on the mean velocity fields and fields of velocity pulsations in the supersonic flows obtained by means of the PIV measurement set “POLIS” are presented. Experiments were carried out in the supersonic blow-down and stationary wind tunnels at the Mach numbers of 4.85 and 6. The method of flow velocity estimate in the test section of the blow-down wind tunnel was grounded by direct measurements of stagnation pressure in the setup settling chamber. The size of tracer particles introduced into the supersonic flow by a mist generator was determined; data on the structure of pulsating velocity in a track of an oblique-cut gas-dynamic whistle were obtained under the conditions of self-oscillations.
																								



2.
Three-wave nonlinear interactions of disturbances in supersonic boundary layer on the solid and porous surfaces

S.A. Gaponov1, N.M. Terekhova2
1 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
2 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: stability, transition, supersonic and hypersonic flows, nonlinear waves
Pages: 353-363

Abstract >>
The interaction of disturbances in supersonic boundary layer is considered within the framework of the weakly nonlinear stability theory for the Mach number M = 2 on the solid and porous surfaces. The interrelations in several triplets composed of two- and three-dimensional waves at the frequencies related by the phase synchronization conditions were modelled. It was found that their interactions on the solid surface are much stronger in the asymmetric triplet. It was found that on a porous surface, the linear increments of vortex disturbances increase considerably, the region of dangerous frequencies widens, and the spatial extension of the existence of growing oscillations increases. Nonlinear interactions are, as a rule, much more intense in comparison with the case of an solid surface; they realize in a broad frequency range, which results to a broadband growth of the Tollmien ⎯ Schlichting subharmonic vortex waves. An increase in the surface porosity leads to the intensification of nonlinear processes.
																								



3.
Transition of the boundary layer on a flat plate at supersonic and hypersonic velocities

V.I. Kornilov1
1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: transition of the boundary layer, supersonic and hypersonic velocities, flat plate, generalization of experimental data
Pages: 365-373

Abstract >>
The transition of the boundary layer from the laminar to the turbulent state on a smooth flat plate at a zero angle of attack is studied in the range of Mach numbers М = 2−6. It is demonstrated that the results measured at the end of the transition region can be approximated by a simple dependence suitable for applications, which does not require additional measurements, is valid in the range of Mach numbers М = 2−10, and, with an error lower than 20 %, can be used to estimate the location of the transition region on a flat plate in geometrically similar wind tunnels.
																								



4.
Investigation of temperature fields in supersonic flow behind a backward-facing step

I.A. Bedarev1, M.A. Goldfeld2, YU.V. Zakharova3, N.N. Fedorova4
1 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
2 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
3 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS Novosibirsk State University of Civil Engineering
4 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: high-enthalpy flows, separation, mathematical modelling, turbulence
Pages: 375-386

Abstract >>
The results of numerical modelling and experimental investigations of high-enthalpy turbulent flows in the neighborhood of 90-degree backward-facing steps at the Mach numbers M= 2−4 are presented. The experiments were conducted in the hot-shot wind tunnel IT-302M of ITAM SB RAS. The computations were carried out on the basis of the full Favres-averaged Navier ⎯ Stokes equations augmented by the Wilcox turbulence model. The temperature factor influence on the flow structure in the separated zone and temperature distributions was investigated numerically for different Mach numbers. The wall temperature is shown to affect significantly the quantity and sizes of recirculation vortices as well as the temperature distribution in the zone of flow separation and reattachment. The computational results are compared with experimental data on the pressure distribution on the model surface and the wave structure of the flow.
																								



5.
Simulation of subsonic flows with separation using the FLUENT program package: software applicability study

V.M. Molochnikov1, N.I. Mikheev2, O.A. Dushina3
1 Research Center for Power Engineering Problems, Kazan Scientific Center RAS
2 Research Center for Power Engineering Problems, Kazan Scientific Center RAS
3 Research Center for Power Engineering Problems, Kazan Scientific Center RAS
Keywords: simulation, separated flow, rib, backward-facing step, nominally laminar flow, turbulence model
Pages: 387-394

Abstract >>
Laminar and turbulent channel flows past a backward-facing step and cross-flow rib were simulated using the commercial FLUENT program package to perform subsequent comparison of FLUENT-simulated data with available experimental results.
																								



6.
Modelling of the flow structure in a composite jet behind two thrusters located near the spacecraft case

YU.I. Gerasimov1, V.N. Yarygin2, A.N. Krylov3, B.A. Sagdullin4
1 Korolev Rocket and Space Corporation "Energia"
2 Kutateladze Institute of Thermophysics SB RAS
3 Kutateladze Institute of Thermophysics SB RAS
4 Moscow Institute of Physics and Technology
Keywords: spacecraft, orientation and control thrusters, rocket blasts, exhaust plumes, jet interaction, flow structure, modelling in vacuum chambers
Pages: 395-404

Abstract >>
The gasdynamic flow structure is studied experimentally and numerically in the zone of jet interaction flowing with considerable underexpansion from two supersonic nozzles located near the spacecraft case. Longitudinal and transversal distributions of the density are obtained by the method of electron beam. They are compared with calculation results for inviscid gas. Generalized dependencies for determination of gas density within the zone of two jets interaction and boundary of this zone are obtained.
																								



7.
Rarefied molecular gas flow near the rotating cylindrical surface

A.P. Andreev1, V.N. Popov2
1 Pomorsky State University
2 Pomorsky State University
Keywords: Boltzmann kinetic equation, model kinetic equations, exact analytic solutions, rarefied molecular gas, cylindrical surface
Pages: 405-410

Abstract >>
An exact analytic solution of the problem of the right circular cylinder in a rarefied molecular gas is constructed in the isothermal approximation. An expression for the velocity of a rarefied molecular gas entrained by the cylinder rotated therein is obtained in the regime of a flow with slip accounting for the second-order correction in terms of the Knudsen number. A generalization of the BGK model of the Boltzmann kinetic equation accounting for the rotational degrees of freedom of gas molecules is used as the governing equation, and the diffuse reflection model is used as a microscopic boundary condition on the cylinder surface. The given approach is shown to enable the consideration of the gas flow dependence on the Prandtl number and the gas temperature.
																								



8.
Vorticity waves in problems of hydrodynamic stability

M.N. Zakharenkov1
1Zhukovsky TsAGI Petrovsky Bryansk State University
Keywords: vorticity, vortex waves, vortex street
Pages: 411-417

Abstract >>
The known problem of flow transition near a circular cylinder at Re = 40 from a symmetrical form to the Karman vortex street can be considered as the problem of vortex wave development and intensification. Development of three bundles of vortex waves of low intensity is observed in a wake of a cylinder; these bundles are easily visualized as the structures of relative vorticity = Ω(t1) − Ω(t0): difference of vorticity Ω at two time moments, t0 being fixed. In the field of the alternating structure of quadrupoles is characterized by linear parameter l = h/d: the ratio of the width of the central bundle of vortex waves to the distance between the centers of quadrupoles of a "single sign". When l = 0.281 is achieved, which coincides with the value of the same parameter of a stable Karman street, the transition from symmetrical streamlining by viscous incompressible liquid to the vortex street occurs.
																								



9.
Stability of the flow of weakly electro-conductive fluid in the presence of a spiral magnetic field

A.V. Proskurin1, A.M. Sagalakov2
1The Altai State University
2The Altai State University
Keywords: magnetohydrodynamics, hydrodynamic stability, viscous fluid
Pages: 419-428

Abstract >>
The stability to small disturbances of the flow in a pipe of annular cross section is considered in the presence of a spiral magnetic field. The investigated duct configuration consists of two infinite coaxial cylinders between which a weakly electroconductive viscous incompressible fluid is placed, which moves under the axial pressure gradient. The azimuthal magnetic field is created by a current flowing through the central cylinder, and the longitudinal magnetic field is created by an external solenoid. The magnetohydrodynamic approximation is used. It is found that the introduction of the azimuthal magnetic field may lead to a flow destabilization as compared to the case of only the longitudinal magnetic field.
																								



10.
Linear stability criterion for steady screw magnetohydrodynamic flows of ideal fluid

YU.G. Gubarev1
1 Lavrentyev Institute of Hydrodynamics SB RAS Novosibirsk State University

Keywords: ideal fluid, magnetic field, steady flows, Lyapunov direct method, stability criterion, instability conditions, a priori estimate
Pages: 429-441

Abstract >>
A linear stability problem for a subclass of steady screw flows of a uniform-density inviscid incompressible ideally conducting fluid in the magnetic field is investigated. The necessary and sufficient condition of theoretical (in semi-infinite time intervals) stability as well as the sufficient conditions for the practical (in finite time intervals) instability of the given flows to small screw disturbances are obtained by the direct Lyapunov method. In the case when the theoretical stability criterion is violated, and the sufficient conditions of practical instability are valid, on the contrary, an a priori exponential estimate from below has been derived for the growth of small disturbances under consideration, and the increment of the exponent contained therein is an arbitrary positive constant.
																								



11.
Oscillatory motion of solid in the liquid

V.L. Sennitskiy1
1 Lavrentyev Institute of Hydrodynamics SB RAS

Keywords: liquid, solid, oscillations, solid mass redistribution
Pages: 443-453

Abstract >>
Exact solutions to two problems of solid rotary oscillation in ideal liquid in the presence of gravitation field  have been obtained.
																								



12.
Interaction of acoustic waves with porous layer

A.A. Gubaidullin1, O.YU. Boldyreva2, D. D. And3
1 Tyumen Division of Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
2Tyumen Division of Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
3 Tyumen Division of Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: porous layer, gap, barrier, acoustic wave, propagation, reflection
Pages: 455-470

Abstract >>
Interaction of sound impulse with porous layer is investigated. The presence of a barrier shielded by the layer and the gap between the porous layer and the barrier is possible. Method of calculation in linear approximation of pressures and tensions in the porous layer, gap, and on the barrier has been proposed. The method serves to interpret data on acoustic waves interaction with porous layer obtained experimentally or with the use of finite-difference methods. Specifics of acoustic wave propagation into the porous layer and further reflection from the barrier has been studied. Comparison of calculation data with experimental data of other authors on impulse propagation through the porous plate submerged in water has been carried out.
																								



13.
Experimental testing of liquid boiling-up homogeneity near the boundary of the attainable superheating

E.V. Lipnyagov1, S.A. Perminov2, G.V. Ermakov3, B.M. Smolyak4
1 Institute of Thermophysics, UrB RAS
2 Institute of Thermophysics, UrB RAS
3 Institute of Thermophysics, UrB RAS
4 Institute of Thermophysics, UrB RAS
Keywords: superheated liquid, boundary of the attainable superheating, stationarity and homogeneous nucleation, average life time of superheated liquid, work of critical nucleus formation, frequency
Pages: 471-484

Abstract >>
Results of measured average expectancy time of n-pentane and n-hexane boiling-up to the boundary of attainable superheating are presented. Experiments have been carried out in glass capillaries with substantially decreasing value of the superheated liquid volume for the preset metastable state (p, T = const). Obtained data fail to prove correlation following from the condition of homogeneity and stationarity of the random process resulting in the superheated liquid boiling-up (J is the frequency of homogenous nucleation, V is the volume of the superheated liquid, is the average life time). Thus, experiments on superheated liquid boiling-up kinetics bound with measurements of average life time in glass capillaries cannot serve a proof of the validity of classical theory of nucleation for superheated liquids since one of the ground conditions ⎯ boiling-up homogeneity ⎯ is not met.
																								



14.
Crisis phenomena in falling liquid films at periodic heat loads

A.S. Surtaev1, A.N. Pavlenko2
1 Kutateladze Institute of Thermophysics SB RAS
2 Kutateladze Institute of Thermophysics SB RAS
Keywords: heat transfer crisis, film flow, liquid nitrogen, alternating pulse heat release, regular metastable structures
Pages: 485-496

Abstract >>
Experimental results on development of crisis phenomena in a falling film of cryogenic liquid at alternating pulse heat release are presented. Experimental data on local temperature evolution along a heat releasing surface are obtained. It is shown that amplitude of heater temperature pulsations depends significantly on the heat flux density and coordinates along the liquid film flow. New experimental data on the critical heat fluxes corresponding to formation of stable dry spots and drying crisis are presented depending on duration of heat release pulses. It is shown that parameters of the forming metastable regular structures and critical drying parameters of the heat-releasing surface are determined by dynamics of the movable boundaries of wetting during self-organization of a system.
																								



15.
Modelling of convective processes during the Bridgman growth of poly-silicon

V.N. Popov
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: convection, poly-silicon, heat and mass transfer, simulation
Pages: 497-506

Abstract >>
An original 3D model was used to numerically examine convective heat-and-mass transfer processes in the melt during the growth of polycrystalline silicon in vertical Bridgman configuration. The flow in the liquid was modelled using the Navier ⎯ Stokes equations in the Boussinesq approximation. The distribution of dissolved impurities was determined by solving the convective diffusion equation. The effects due to non-uniform heating of the lateral wall of the vessel and due to the shape of the crystallization front on the structure of melt flows and on the distribution of dissolved impurities in the liquid are examined.
																								



16.
Two-phase zone at Аl2О3 melting by laser radiation and at melt solidification under the conditions of free cooling

V.K. Bityukov1, V.A. Petrov2, I.V. Smirnov3
1 Moscow State University of Radio Engineering, Electronics, and Automatics (Technical University)
2 Moscow State University of Radio Engineering, Electronics, and Automatics (Technical University)
3 Moscow State University of Radio Engineering, Electronics, and Automatics (Technical University)
Keywords: alumina, two-phase zone, laser heating, free cooling, brightness temperature, plateau, crystallization, structure
Pages: 507-518

Abstract >>
Experiments and numerical simulation have shown that the two-phase zone of liquid and solid phases concentration, variable over the coordinate, is formed both at alumina heating by laser radiation and at free melt cooling. During heating this zone is formed only at the initial stage of heating. Its width is not large and is lesser than the depth of the heating laser beam penetration due to the effect of intense heat losses through the crystal by thermal radiation and thermal conductivity. Extension of the two-phase zone formed at crystallization is much more under the conditions of free cooling than at melting, and it can cover almost the whole thickness of the melt. Temperature plateau of the brightness (effective) temperature registered at solidification by the pyrometer with the wavelength of 0.65 μm is explained by formation of the extensive two-phase zone. However, this plateau is realized not for all wavelengths. The importance of the melt absorption coefficient influence on probable appearance of temperature plateau is shown. As a result of crystallization with the two-phase zone formation, porous structure consisting of the crystals with small size can be formed. It may cause the diffuse surface reflectivity.
																								



17.
Thermal instability of glow discharge in the gas loop of СО2 laser with extended disk fans-heat exchangers

YU.V. Afonin1, A.P. Golyshev2, A.M. Orishich3, YU.M. Prikhod'ko4, V.P. Fomichev5
1 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
2 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
3 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
4 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
5 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
Keywords: diametral disk fan-heat exchanger, СО2 laser, gas loop, heat transfer
Pages: 519-527

Abstract >>
СО2 lasers with transverse discharge and convective gas cooling find ever-increasing application. One strategy in making such lasers more efficient radiators is increasing the rate of the gas flow through the discharge zone with the help of diametral disk fans-heat exchangers. The application of such fans-heat exchangers, however, entails serious difficulties related to the glow discharge-gas flow interaction. In the present study, we investigate the stability problem for volume discharge in the gas loop of a СО2 laser with diametral disk fans-heat exchangers.