

2018 year, number 6
S.O. Morozov^{1}, S.V. Lukashevich^{1}, V.G. Soudakov^{2}, A.N._{ }Shiplyuk^{1}
^{1}Khristianovich Institute of Theoretical and Applied Mechanics SB RAS,Â Novosibirsk, Russia ^{2}Zhukovsky Central Aerohydrodynamic Institute,Â Zhukovsky, Russia Email:Â morozov@itam.nsc.ru
Keywords: hypersonic boundary layer, passive porous coating, boundarylayer stability, laminarturbulent transition, secondmode disturbances.
Pages: 793–800
Abstract >>
The present work was devoted to an experimental study of small angles of attack and cone nose bluntness on the efficiency of stabilization of highfrequency disturbances in hypersonic boundary layer with a passive porous coating. The experiments were carried out on a cone with an apex halfangle 7° and nose bluntness radii R = 0.03, 0.5 and 1 mm installed under angles of attack a = 0–1° at the freestream Mach number M_{¥} = 5.8. Highfrequency pressure ﬂuctuations on the sides of the cone with the solid and porous surfaces were measured. It is shown that at all angles of attack and cone bluntness, the passive porous coating permits an efficient suppression of disturbances in hypersonic boundary layer both on the windward and leeward sides of the cone.

M.M. Katasonov^{1}, A.M. Pavlenko^{1}, V.V. Kozlov^{1,2}
^{1}Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
^{2}Novosibirsk State University, Novosibirsk, Russia
Email: mikhail@itam.nsc.ru^{}
Keywords: boundary layer, separation, laminarturbulent transition, longitudinal localized structure, wave packet
Pages: 801–807
Abstract >>
The hotwire anemometry technique is used to study the development of controlled disturbances in a straight wing boundary layer. Threedimensional surface oscillations with large amplitude generate two types of disturbances: the localized longitudinal structures and wave packets. In downstream direction, the intensity of localized longitudinal structures decreases. The wave packets manifest themselves near the fronts of longitudinal localized structure in the flow region with adverse pressure gradient. In the separation flow area, an intensive growth of the wave packets amplitude is observed. The spatial development of the wave packets coincides with the development of threedimensional TollmienSchlichting wave under similar conditions.

P.I. Geshev^{1,2}, A.I. Chernykh^{1,3}
^{1}Novosibirsk State University, Novosibirsk, Russia
^{2}Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
^{3}Institute of Automation and Electrometry SB RAS, Novosibirsk, Russia
Email: geshev@itp.nsc.ru
Keywords: ideal fluid, point vortex, Hamiltonian, exact integration, stochastic trajectories
Pages: 809–822
Abstract >>
The Hamiltonian equations of the motion of a system of N ideal point vortices in a simply connected twodimensional region have been obtained by the methods of the theory of functions of a complex variable. It is shown that the motion of two vortices in a circle is integrated exactly; the periods of this motion have been determined. The motion of two vortices in a region bounded by a lemniscate has been investigated by the method of secant planes in the phase space. The stochastic trajectories have been revealed here, which have continuous power spectra. The supposed reason for stochasticity is the walk of the phase point over a homoclinic structure.

V.N. Zinovyev, I.V. Kazanin, V.A. Lebiga, A.Yu. Pak, N.G. Tsibulsky, A.S. Vereshchagin, V.M. Fomin
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia Email: zinoviev@itam.nsc.ru, kazaniniv@gmail.com
Keywords: helium, microspheres, helium permeability, gas separation, natural gas, membranesorption method
Pages: 823–831
Abstract >>
The paper is devoted to the study of the permeability of hollow microspherical membranes to helium with a narrow fraction of MSV1L microspheres taken as an example. In the course of the study, a special experimental facility for obtaining the sorption curves of various gases at given pressures and temperatures was created. A procedure for carrying out experiments and processing experimental data with the aim of evaluating the coefficient of helium permeability for the investigated type of hollow membranes was approbated. For the selected narrow fraction of MSV1L microspheres with diameters in the range from 35 to 50 mm, the helium permeability coefficient of the particlewall material in the temperature range from 20 to 110_{ }°C and the activation energy of the helium sorption process by the microspheres were determined.

M.A. Pakhomov and V.I. Terekhov
Kutateladze Institute of Thermophysics SB RAS,
Novosibirsk, Russia
Emails: pakhomov@ngs.ru, terekhov@itp.nsc.ru
Keywords: gasdroplet flow, separation, swirl, evaporation, numerical simulation, turbulence, model of Reynolds stress transport
Pages: 833–843
Abstract >>
The effect of flow swirl parameter and thermophysical properties of the droplet of water, ethanol, and acetone on the structure of turbulent flow and heat transfer in a gasdroplet flow was studied numerically. To describe the dynamics and heat and mass transfer of the twophase flow, the Eulerian approach was used. The growth of the volume fraction of small particles on the tube axis is typical of a swirling flow because of their accumulation in the zone of reverse flows due to the turbophoresis force. It is shown that the addition of droplets leads to a significant increase in heat transfer (more than 2.5 times) at mass concentration of droplets M_{L}_{1} = 0.1 in comparison with a singlephase swirling flow. Intensification of heat transfer with the use of ethanol droplets is higher than that for water droplets (approximately 10–20 %) and acetone (up to 65 %). When using the droplets of ethanol and acetone, the region of twophase flow existence reduces, and the degree of suppression of carrier phase turbulence decreases. This is due to a more rapid evaporation of droplets of volatile liquids.

Y.M. Kulikov, E.E. Son
Joint Institute for High Temperatures RAS, Moscow, Russia Email: kulikovyurii@yandex.ru; son.eduard@gmail.com
Keywords: òthermoviscosity, inflection point, random noise, mixing, correlation filter, correction for divergence, turbulence
Pages: 845–864
Abstract >>
This paper deals with 3D flow of thermoviscous fluid in the low compressibility approximation within a cubicshaped domain enclosed between two flat plates with different temperatures. For two other directions, the problem statement assigns periodic boundary conditions, while the steady pressure drop is sustained for the head flow direction. Such formulation allows to trace the evolution of initial disturbances imposed on the main flow depending on perturbation properties. In this case, we consider a degenerate onedimensional divergencefree noise that is modified by a special correlation filter. When the divergent noise is generated, the solenoid nature of random velocity field must be restored. The simulation demonstrates that random disturbance field development leads to two different scenarios: for the first lowamplitude case, the velocity profile loses initial inflection point and its flowrate increases by 1.51.6 times, but for the second one, the flow turbulization occurs destroying the flow core and decreasing the flowrate. In both outcomes, the transition to a steady flow mode in terms of either stationary velocity fields or statistical averages takes place for a long interval: up to dimensionless time units. The analysis of
simulated flow is based on integral kinetic energy curves and enstrophy and
also via spatial averaging of the obtained data arrays.

Yu.O. Kabova^{1}, V.V. Kuznetsov^{2,3}, O.A. Kabov^{1,3}
^{1}Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
^{2}Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, Russia
^{3}Novosibirsk State University, Novosibirsk, Russia
Email: kabov@itp.nsc.ru
Keywords: twophase flows, rivulets, microchannels, numerical studies
Pages: 865–874
Abstract >>
The joint steadystate motion of a rivulet of incompressible liquid and a gas flow in a microchannel was studied taking into account the action of gravity forces, tangential stress at the gasliquid interface, and Van der Waals forces. The values of contact angle are calculated for various values of liquid and gas flow rates. It is shown that for a constant liquid flow rate, an increase in gas velocity leads to a decrease in the height of rivulet, and the surface of rivulet becomes flatter. A significant deforming effect of rivulet on the velocity distribution in gas is found.

S.P. Aktershev^{1}, A.A. Levin^{2}, I.V. Mesentsev^{1}, and N.N. Mesentseva^{1}
^{1}Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia ^{2}Melentiev Institute of Power Engineering Systems SB RAS, Irkutsk, Russia Email: sergeyaktershev@mail.ru
Keywords: boiling, subcooled liquid, evaporation, condensation, pressure pulsations, selfoscillations
Pages: 875–887
Abstract >>
The results of an experimental and theoretical investigation of highly subcooled ethanol in an annular flowpassage duct under the conditions of pulsed heat generation in the wall cooled by liquid flow are presented. The formation of a vapor film on the heater wall and longlasting pressure oscillations of high amplitude in the duct (the selfoscillatory regime) have been observed in experiments. A mathematical model of the ethanol boiling up has been developed to take into account the evaporation of the overheated liquid near the heater wall and the vapor condensation in the flow of a subcooled liquid. The proposed model describes both the decaying oscillations of the vapor layer and the development of the selfoscillatory regime, which predicts well the amplitude and frequency of nonlinear oscillations. Numerical computations have shown that the selfoscillatory regime is realized due to evaporation of a periodically renewed microlayer on the heater wall. Computational results agree well with experimental data.

T.Kh. Salikhov, Yu.P. Khodjaev
SRI of Tajik National University,
Dushanbe, Republic of Tajikistan
Email: tsalikhov@mail.ru
Keywords: temperature field, photoacoustics, twolayer systems
Pages: 889–896
Abstract >>
Based on the system of nonlinear equations of thermal conductivity for stationary temperatures of the gas layer, substrate, the first and the second layers of samples with a volumetric optical absorption coefficient, the features of the formation of a stationary temperature field in the photoacoustic cell have been investigated. Analytical expressions for the temperature field of the gas layer, two layers of the sample and the substrate, as well as a system of interrelated nonlinear algebraic equations for the steadystate temperature of the irradiated and rear surfaces of the first layer and the boundary between the second layer and the substrate have been obtained. The numerical solution of the system of nonlinear algebraic equations shows that with the increase of the absorption coefficient of the corresponding layer and the gradual transition from the condition (is the layer thickness) to the condition, heating increases significantly, and the dependences of the characteristic temperatures on the intensity of the incident beam become nonlinear. It is shown
that the sign of the thermal coefficient of the temperature dependence of emissivity
significantly affects the dependences of the temperature increment of the
surfaces of all layers on the intensity of the incident beam.

D.V. Sergachev^{1}, O.B. Kovalev^{1}, G.N. Grachev^{2}, A.L. Smirnov^{2}, P.A.Â Pinaev^{2}
^{1}Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia ^{2}Institute of Laser Physics SB RAS, Novosibirsk, Russia Email: yosergach@gmail.com
Keywords: twophase flow, pulsed laser radiation, evaporation, vapor recoil pressure, reactive acceleration, optical diagnostics
Pages: 897–908
Abstract >>
The problem of measurement of the inflight velocity and temperature of particles in the light field of a pulsedperiodic laser was solved using contactless detection methods. The solution of the problem is based on using a spectrometer and a complex of laser and optical means. The diagnostic technique combines two independent methods for measuring the inflight particle velocity: a passive one, based on the registration of the natural radiation emitted by the heated particles in the gas flow, and an active one, using the effect due to laserbeam scattering. Histograms of the statistical distributions of particle velocities for two operating modes of a coaxial nozzle were presented. There is no laser radiation in the first mode. There is pulsed laser radiation in the second mode. In the experiments, various powders (Al_{2}O_{3}, Mo, Ni, Al) with particle size distributions typical of laser deposition technology and various working gases (air, nitrogen, argon) were used. ÑÎ_{2}laser works in
pulseperiodic mode with a mean power up to 2 kW. Pulsed power reaches
several ten/hundred kilowatts. It is shown that in the field of laser
radiation, powder particles acquire additional acceleration due to the
evaporation and the appearance of a reactive force due to the recoil pressure
of the vapors emitted from the irradiated part of the particle surface. It
is shown that laser radiation can significantly affect the velocity and
temperature of powder particles being transported by a gas jet. At the maximum
carriergas velocity of up to 30 m/s, the velocities of single particles
due to the laserinduced acceleration can reach the values of the order of
120 m/s.

U.K. Zhapbasbayev, S.E. Kudaibergenov, A.E. Mankhanova, and R.M. Sadykov
Kazakh National Research Technical University after K.I. Satpaev, Almaty, Kazakhstan
Email: uzak.zh@mail.ru
Keywords: highly viscous oil, alkalinesurfactantpolymer (ASP) flooding, Winsor type III emulsion, phase behavior
Pages: 909–916
Abstract >>
The
paper presents experiments on using alkalisurfactantpolymer compositions (for ASP flooding) in tests on cores saturated with highly viscous
oil. The phase behavior was evaluated for solutions with different
concentrations of alkali (NaOH) and surfactant (SDS) after mixing with highly viscous oil samples; this defined
the optimal agent compositions for producing Winsor type III emulsions. Experiments on core saturated with highly
viscous oil demonstrated the pumping of ASP agent in the form of aquatic
solutions surfactant/alkali and polymer after regular water flooding
give the gain in the oil displacement in the range from 19 to 37 %.

K.Yu. Arefyev^{1,2,3}, K.V. Fedotova^{1,2}, L.S. Yanovsky^{1,4}, M.A. Ilchenko^{1}, and K.T. Niazbaev^{1,2}
^{1}Baranov Central Institute of Aviation Motors, Moscow, Russia ^{2}Bauman Moscow State Technical University, Moscow, Russia ^{3}Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia ^{4}Institute of Problems of Physical Chemistry, Chernogolovka, Moscow Region, Russia Email: fedkv_89@mail.ru
Keywords: solid hydrocarbons, simulation, twochamber lowtemperature gas generator, LTGG, sublimation, azines
Pages: 917–928
Abstract >>
The paper presents a
mathematical model and calculation results for the process of gasification of
solid hydrocarbons (SHC) placed in form of spherical bedding inside channels
with variable cross section and washed with hightemperature gas. Parametric
study was performed for analysis of generator performance (mass flow rate and
gasification products) as function of different parameters: temperature and
composition of gas phase, thermophysical properties of SHC, sphere diameter in
the bedding, and channels configuration. The method for estimating the SHC
gasification process in a flow duct of low temperature gas generator (LTGG)
without loss of spheres shape (due to melting) was developed. The method offers
recommendations for obtaining the required level of mass flow rate and gas
temperature at the generator exit. These data can be used for analysis of
experimental results on SHC sublimation at the stage of preliminary
designing of the LTGG.

A.M. Kler, E.L. Stepanova, and A.S. Maksimov
Melentiev Energy Systems Institute SB RAS, Irkutsk, Russia
Email: step@isem.irk.ru
Keywords: steamturbine heating plant, mathematical modeling, optimization, efficiency of heat power equipment, steam turbine with back pressure, wasteheat recovery
Pages: 929–938
Abstract >>
The
article considers a promising steamturbine heating plant, which includes a
steam turbine with back pressure and a steam boiler operating on natural gas,
with waste heat recovery. The mathematical model of à
steamturbine heating plant has been developed to perform one design
calculation in the nominal mode and several verification calculations in
characteristic modes with different thermal loads. Optimization calculations of
the unit were carried out for two regions with different climatic conditions
and different fuel prices. The optimal design parameters of the equipment,
the parameters of the working fluid and coolants at all points of the
technological scheme, as well as fuel costs in each characteristic mode of
operation have been found by the criterion of the minimum price of electricity.
The considered steamturbine heating plant provides a higher heat utilization
coefficient of the fuel than the traditional heating plant.

