|
Vestnik NSU. Series: Physics. 2015. V10, i 3 |
|
Physics of Field, Neutral and Ionized Gases |
|
I. D. Zverkov, A. V. Kryukov, G. R. Grek I. S. Konovalov, G. Yu. Evtushok Definition of the Parameters of Surface Undulations for Small Scale Aircraft Wing This work is devoted to investigation of flow parameters on classic and wavy wing with Z-15-25
profile in area of Reynolds number from 0,35 to 2 x 10^5 with a = 0°. The oil-film visualization are demonstrate the transformation of separation area on low Reynolds wing surfaces. Influence of distribution
of a pressure gradient on a profile upon the sizes of separation area is shown and limits of
applicability of a wavy surface of a wing are defined. The thermoanemometric data provided to determine
boundary layer thickness and pulsation characteristics. As shown that at Reynolds number
area 0,6–2 x 10^5 the mechanisms of flow instability and laminar-turbulent transition are invariable
and depend from local boundary layer parameters at preseparation area. As well as for a classical
wing, in the area of a groove of a wavy wing, the central frequency of a package of waves of instability
of a shift layer can be well foretold both by means of the linear theory of stability, and by
means of a hypothesis that the wavelength of the running indignations is proportional to the doubled
boundary layer thickness. At result the technique of a finding of parameters of a undulations of a
wing for any profile in the range of numbers of Reynolds from 10^4 äî 10^5 is offered. |
|
Pavlenko A. M., Zanin B. Yu., Katasonov M. M. Investigations of a Flow around the FLYING Wing Model at Natural Reynolds Numbers Studies of flow structure near the surface model of drones have been conducted in the subsonic
wind tunnel. Experimental data of flow visualization depending on attack angle were obtained by
oil film method. Evolution of flow patterns inside the regions of boundary layer separation in different
configurations was demonstrated. Ability of separation control and reduction zones of flow
separation by local influence (ribs and cones) has been also studied on the wing surface. |
|
Zamuraev V. P., Kalinina A. P. Influence of the Variable Parameters Jet Flowing through the Slit on the Supersonic Gas Flow in the Expanding Channel Influence of the jet flowing from a gas generator through a narrow slit on shock-wave structure
of a stream in the channel of variable section is investigated. Influence of the size of a jet, density
and speed of gas on an entrance, and also influence of oscillations of parameters of a jet is studied.
Possibility of management of a supersonic stream of shock-wave structure in the channel with the
help pulse and periodic an energy supply before a jet is investigated at negative feedback on pressure. |
|
Gaponov S. A., Terekhova N. M. The Combined Influence of Heat and Mass Transfer through a Porous Wall on the Boundary Layer Stability Compressible Gas at High Mach Numbers This work continues the research on modeling the management regime in the boundary layer of compressible gas. The effect of the distribution of heat and mass transfer on the stability characteristics of supersonic boundary layer at high supersonic Mach number M = 5,35. The focus is on the modeling of acoustic disturbances in the conditions as a normal injection, in which the only nonzero component of the average velocity V, and the injection of other areas, including tangential, when the wall is not zero only U component. Production close to the problem of influence on the development of gas curtain small oscillations. It is assumed that the effect of injection of a homogeneous gas of different temperature similar to that of the blowing gas of different density, namely, blowing cold gas simulates heavy gas blowing and vice versa. Therefore in this modeling work is achieved by changing the factor of temperature (heating or cooling of the walls). The variant when the socalled regime implemented «lock» when the velocity perturbations on the porous surface can be taken as zero. |
|
Lysenko V. I., Gaponov S. A., Smorodsky B. V., Ermolaev Yu. G., Kosinov A. D., Semionov N. V. On the Influence of Porous Coating Thickness on Supersonic Boundary Layer Stability Theoretical and experimental investigation of the influence of porous-coating thickness on the stability of the supersonic flat-plate boundary layer at free-stream Mach number M = 2 have been performed. Good quantitative agreement of experimental data obtained with artificially generated disturbances performed on models with various porous inserts and calculations based on the linear stability theory has been achieved. It is shown that the increase of the porous-coating thickness leads to the boundary layer destabilization. |
|
Kornilov V. I., Boiko A. V., Kavun I. N. Flat-Plate Skin Friction under the Conditions of Air Blowing through a Wall with Intermittent in Length Permeability Possibility of turbulent skin-friction reduction in an incompressible boundary layer of a flat plate with air blowing through a microperforated surface consisting of alternating permeable and impermeable sections was studied experimentally and computationally. The mass flow rate of the air per unit area was varied in the range from 0 to 0.0709 kg/s/m2, which corresponds to the maximum blowing coefficient equal to 0.00344. A consistent reduction of the local skin-friction values along the chord of the microperforated insert was found, the reduction achieving nearly 70 % at the end of the last active blowing sections, except the impermeable surface sections demonstrating, on the contrary, the skin friction increase: the longer section, the higher skin friction. |
|
Kozulin I. A., Kuznetsov V. V. Experimental Study Structure of Gas-Liquid Flow in Rectangular Minichannel by Optical Methods In this paper, using method of two-beam laser scanning and high-speed video was identified patterns of distribution phases in the cross-section of the rectangular channel 0.72 x 1.50 mm with hydraulic diameter of the order to capillary constant. The structure of the gas-liquid flow was studied including flow regimes and statistical characteristics of the two-phase flow in regime with elongated bubbles, transition flow and annular flow regime. |
|
Vorobyev M. A., Kashinsky O. N., Lobanov P. D., Chinak A. V. Regimes of Bubble Generation in the Flow of Viscous Liquid Data of experimental study of the processes arising at gas injection through a capillary in to the liquid flow are presented. The characteristic modes of gas-liquid bubble mixture formation are investigated. Bubble coalescence near the capillary edge was shown to produce different modes. Glycerol was applied as working liquid. Its heating was made to change physical properties of working liquid. |
|
Berdnikov V. S., Mitin K. A., Mitina À. V. Influence of Relative Size of the U-Shaped Silicon Rod on Conjugate Heat Transfer in the Regime of Gas Buayancy Induced Convection The influence of relative cross-section size of an electrically heated U-shaped silicon rod which is placed in a gas-filled rectangle container with isothermal cold walls on conjugate heat transfer in the regime of buoyancy induced convection was numerically studied in three-dimensional formulation. The natural convection equations in the Boussinesq approximation in term temperature, velocity vortex and velocity vector potential were solved by the finite element method. The spatial form of convective flow and temperature fields in liquid and solid body were studied. It was show that spatial form and intensity of convective flows is significantly depends on the cross-section size of U-shaped silicon rod. This is has strong influence on the temperature field in a solid body. |
|
Izmaylova G. R., Kovaleva L. A., Nasyrov N. M. Mathematical Modeling of Radio-Frequency Electromagnetic and Acoustic Impact on Formation in Combination with Solvent Injection We investigate the possibility of increasing the efficiency of extraction of high-viscosity oil combined effect of radio-frequency (RF) electromagnetic (EM) and acoustic fields on the formation and miscible displacement oil solvent. A mathematical model of two-stage impact on the oil reservoir. At the 1st stage, the heating of the formation RF electromagnetic and acoustic field. At the 2nd stage the RF heating of the formation with simultaneous injection of low-viscosity solvent. |
|
Solid-State and Semiconductor Physics, Physics of Nanostructures |
|
Cherepanov A. N., Popov V. N. Analys of Modification of the Heat Resistant Alloy by Nano-Size Refractory Particles The iron-nickel alloy Inkonel-718 is taken an example to consider the material modification with the powders of refractory compositions. Under consideration are theoretical and experimental analysis of the modifiers effect on crystallization kinetics, structuring and mechanical properties of the solidified alloy. |
|
Chemical, Biological and Medical Physics |
|
Andryushchenko V. A., Chekmarev S. F. Folding of Trp-cage Protein in Equilibrium and Nonequilibrium Conditions: Molecular Dynamics Simulations The study of the dynamics of protein folding into its functional (native) state is one of the actual
problems of molecular biology. For this, molecular dynamics simulations are widely used. The conditions
under which the simulations are performed are important for the correct description of the
folding process. In the present paper, we study the folding dynamics of one of the benchmark proteins
(Trp-cage) under two conditions – the equilibrium conditions, when the protein repeatedly
folds and unfolds, and under nonequilibrium conditions, when an ensemble of trajectories is generated
that start in an unfolded sate of the protein and are terminated in the native state, which corresponds |
|
|
Our Contributors |
|
|
Instructions to Contributors |
|
|
|
|