HEAT AND MASS TRANSFER IN DISPERSED AND POROUS MEDIA FRACTAL PROPERTIES OF CAPILLARY IMBIBITION OF ROCKS
V. L. Barabanova and A. A. Lyubushinb
In a series of laboratory experiments, the deterministic and fractal parameters of spontaneous capillary imbibition
of rocks have been investigated. The capillary imbibition of higher-permeability samples was characterized
by a sharp increase in the saturation at the initial stage and a further increase that is not described
by the power law. Analysis of the parameters of the multifractal spectrum of water-saturation variations of
the investigated samples in the process of capillary imbibition has shown that the generalized Hurst constant
tends to decrease with time in the process of imbibition.
Keywords: deterministic and fractal parameters of spontaneous capillary imbibition of rocks, multifractal spectrum
of water-saturation variations.
INITIAL STAGE OF IMBIBITION OF A POROUS MATERIAL WITH ALLOWANCE FOR CONVECTIVE MASS TRANSFER
A. I. Moshinskii
Consideration has been given to a model of heat- and mass-exchange processes in a porous body with two
types of pores that is suitable for description of the initial stage of penetration of a substance into a porous
system (or of the inverse process: withdrawal of a substance from it). Convective transfer of the substance is
allowed for in large channels (pores). The solution of the problem with supplementary conditions, which are
typical in practice and with which the kinetic function of imbibition (withdrawal) of the porous medium and
the density of the substance flux from the body were found, has been obtained. Certain limiting cases have
Keywords: mass exchange, porous body, two-component nature, imbibition.
SUPPRESSION OF OSCILLATIONS OF THE VAPOR–LIQUID PHASE BOUNDARY IN BOILING OF SUPERFLUID HELIUM INSIDE A POROUS BODY
A. P Kryukov and Yu. Yu. Puzina
This work seeks to investigate the processes of boiling of helium-II on the heater surface under various conditions.
The task of determining dynamic characteristics in the process of evolution of the vapor film on the
surface of a cylindrical heater in the presence of a confining coaxial porous structure is set. The processes
in a free volume and under constrained conditions are compared. The existing experimental data on the boiling
of helium-II on the sphere surface are analyzed. The results of video filming of the boiling of superfluid
helium under zero-gravity conditions on the surface of a thin wire are interpreted.
Keywords: superfluid helium, film boiling, porous structure, zero gravity, experiment.
MAGNETOHYDRODYNAMIC TRANSIENT FLOW THROUGH A POROUS MEDIUM BOUNDED BY A HOT VERTICAL PLATE IN THE PRESENCE OF RADIATION: A THEORETICAL ANALYSIS
Sahin Ahmed and Karabi Kalita
The transient magnetohydrodynamic free convective flow of a viscous, incompressible, electrically conducting,
gray, absorbing–emitting, but non-scattering, optically thick fluid medium which occupies a semi-infinite porous
region adjacent to an infinite hot vertical plate moving with a constant velocity is analyzed. A uniform
magnetic field is assumed to be applied transversely to the flow. The Darcian viscous flow model for the porous
medium is used. The momentum and thermal boundary-layer equations under physically realistic boundary
conditions are solved through the use of the Laplace transform technique. The influence of the
characteristic parameters of the problem on the velocity, temperature, and shear stress is investigated.
Keywords: magnetohydrodynamic flow, radiation–conduction, Darcian model, Rosseland approximation, inverse
permeability, Laplace transforms.
ON THE VORTEX EJECTION IN A CHAMBER WITH A SWIRLING AIR FLOW
E. A. Pitsukha,a Yu. S. Teplitskii,b and V. A. Borodulyab
The longitudinal (axial) velocities of the air in a vortex chamber of diameter 0.393 m were experimentally investigated
at different values of the tangential and bottom blows. On the basis of the data obtained, the back
(adjoint) flow of air blown from the atmosphere through the outlet of the chamber (vortex ejection) was calculated.
The dependence of this flow on the relative radius of the outlet of the chamber, the Rossby number,
and the value of the bottom blow was determined.
Keywords: vortex ejection, tangential blow, bottom blow, outlet, longitudinal (axial) velocity of air, Rossby
number, swirling air flow.
ON THE VELOCITIES OF PARTICLES IN THE VORTEX ZONE OF A VORTEX-BED CHAMBER
Yu. S. Teplitskiia and E. A. Pitsukhab
A simple method for estimating the velocities of small particles in the vortex zone of a vortex-bed chamber,
which is based on the measurement of the velocity of a gas in this chamber and on the balance of the forces
acting on these particles, has been developed.
Keywords: vortex-bed chamber, vortex zone, gravity force, Coriolis force, centrifugal force, drag force, velocity
of a gas, velocity of a particle, Stokes formula.
INFLUENCE OF REYNOLDS AND STROUHAL NUMBERS ON THE DIRECTION OF THE WAVE FORCE ACTING
ON INCLUSIONS IN A STANDING SINUSOIDAL WAVE
L. A. Gubaidullin and P. P. Osipov
The inclusion drift in a standing sinusoidal fluid-velocity wave at various Reynolds and Strouhal numbers
under the action of the viscous force, the virtual mass force, and the buoyancy force has been investigated.
It has been established that at low frequencies the wave force of dense inclusions is directed to the nearest
node, and for loose inclusions it is directed to the antinode of the fluid-velocity wave. For a given inclusion
density, as the standing wave frequency increases, its threshold value, above which the direction of the wave
force reverses, is attained sooner or later. For various Reynolds and Strouhal numbers, the dependences of
the squared threshold drag coefficient on the inclusion density number have been found. These dependences
show that with increasing Reynolds and Strouhal numbers the threshold value of the squared drag coefficient
Keywords: particle drift, forces in acoustic wave fields.
HEAT AND MASS TRANSFER IN THE PROCESS OF MOVEMENT OF WATER DROPS IN A HIGH-TEMPERATURE GAS MEDIUM
O. V. Vysokomornaya, G. V. Kuznetsov, and P. A. Strizhak
The heat and mass transfer in the process of movement of water drops in a high-temperature gas medium
was numerically investigated. The regimes and conditions of formation of the zone of mutual influence of two
drops were determined on the basis of an analysis of the temperature and concentration fields of the water
vapor in the neighborhood of the trajectory of movement of the drops. The times of existence (complete
evaporation) of one and two drops as a result of their interaction with the high-temperature products of combustion
of a typical condensed liquid substance were compared. It has been established that only in the case
where the distance between the two drops is small is the intensity of evaporation of water from them substantially
lower than that of a single drop.
Keywords: heat and mass transfer, high-temperature gas medium, drop, condensed liquid substance, temperature
and concentration fields of the water vapor.
INVESTIGATION OF THE PROCESS OF DRYING OF PLANE MOIST MATERIALS BY THE METHOD OF GENERALIZED
A. I. Ol’shanskii
Equations for calculation of the basic parameters of the kinetics of drying in the period of a dropping rate
have been established. A graphoanalytical method of calculating the process of drying in the second period
has been presented.
Keywords: generalized time, relative drying rate, relative temperature, Nusselt number, Rehbinder number, relative
INVESTIGATION OF THE PROCESSES OF DRYING OF POROUS CERAMICS BY THE DOKUCHAEV–SMIRNOV METHOD
A. I. Ol’shanskii
The kinetics of drying of porous ceramics has been investigated by the Dokuchaev–Smirnov method. A procedure
for processing of experimental data for the calculation of the drying curve has been presented. Equations
for determination of the basic parameters of the kinetics of drying of porous ceramics have been
Keywords: drying time, generalized drying time, maximum drying rate, critical moisture content, mean-integral
HYDROGASDYNAMICS IN TECHNOLOGICAL PROCESSES ROLE OF COMPRESSIBILITY IN THE FORMATION
OF THE STRUCTURE OF A FLOW IN A CHANNEL WITH PERMEABLE WALLS
K. N. Volkov
The flow of a compressible viscous fluid in a channel with a blow was numerically simulated. The results of
a computational experiment were compared with approximate solutions and calculation data presented in the
literature. The results obtained allow one to estimate the role of the compressibility of a fluid in the formation
of the structure of its flow in a channel with permeable walls. It has been established that the compressibility
of this fluid leads to an increase in the curvature of the lines of its flow near the blow surface and to
a filling of the profile of the axial velocity of the flow.
Keywords: blow, channel, compressibility, numerical simulation.
SIMULATION OF A NONSTATIONARY FLOW IN A CHANNEL WITH A DISTRIBUTED BLOW FROM THE CHANNEL WALLS AND FORCED PRESSURE OSCILLATIONS
K. N. Volkov
A nonstationary flow in a channel with a blow was simulated on the basis of the Reynolds-averaged Navier–
Stokes equations and the two-parameter k–ε model of turbulence. The pressure near the left end of the channel
changes by the harmonic law. It was established that the k–ε model of turbulence can be used for
calculating the nonstationary flows formed in the indicated channel by a blow.
Keywords: turbulence, blow, channel, nonstationarity, numerical simulation.
CONVECTIVE HEAT TRANSFER IN THE MOTION OF A MEDIUM UNDER THE CONDITIONS
OF SUPERCRITICAL PRESSURES
G. I. Isaev, S. D. Abdullaeva, K. S. E′iyubova,
and Z. G. Tagieva
Results for heat transfer of hydrocarbons under the conditions of supercritical pressures are presented, and
the equation for the boundary of individual heat-transfer regimes is proposed.
Keywords: critical pressure, heat transfer, heat exchange, specific heat, wall temperature, heat flux density.
MATHEMATICAL MODELING OF THE LAMINAR REGIME OF CONJUGATE CONVECTIVE HEAT TRANSFER
IN AN ENCLOSURE WITH AN ENERGY SOURCE UNDER SURFACE-RADIATION CONDITIONS
S. G. Martyusheva and M. A. Sheremeta,b
A numerical analysis of the laminar regime of heat transfer in a square enclosure with finite-thickness heatconducting
walls in the presence of a constant-temperature heat-releasing element under the conditions of radiative
heat exchange has been made in a surface-radiation approximation. A mathematical model has been
formulated in dimensionless variables "stream function–vorticity–temperature," which was realized numerically
by the finite-difference method. Temperature and streamline distributions reflecting the influence of the reduced
emissivity factor of interior surfaces of enclosing walls, of the relative thermal-conductivity coefficient,
and of the factor of unsteadiness on the flow regimes and heat transfer have been obtained.
Keywords: heat transfer, radiative heat exchange, surface radiation, finite-difference method.
ON THE APPEARANCE OF SELF-OSCILLATORY CONDITIONS OF GAS AND GAS-DROPLET MIXTURE FLOW OUT
OF A VESSEL INTO A COUNTERPRESSURE MEDIUM
V. I. Timoshenko and V. P. Galinskii
The present paper discusses the problem of flow of a gas and a gas-dispersion mixture out of a vessel with
given pressure and stagnation temperature through a channel into a medium with a given pressure. The influence
of energy and gas mass supplies distributed over the channel length, as well as of the kind of injected
gas and its combustion, on the flow character is analyzed. On the basis of the analysis of the results of the
numerical solution of quasi-one-dimensional dynamic equations of the gas and the gas-dispersion mixture, it
has been shown that at a certain intensity of the considered actions the transition of the flow conditions from
stationary to self-oscillatory ones can take place. From the viewpoint of the homogeneous and two-velocitytwo-
temperature models of the gas-droplet mixture the main laws of the influence of droplet evaporation on
the parameters of this transition have been elucidated.
Keywords: self-oscillations, channel flow, mass and energy supply, two-phase medium, homogeneous model,
quasi-one-dimensional equations, numerical calculation.
SIMULATION OF THE TURBULENT-ENERGY REDISTRIBUTION IN A DILUTED POLYMER SOLUTION
G. A. Voropaev and N. F. Dimitrieva
A model of transfer of the Reynolds stresses in a turbulent flow of a low-concentration aqueous polymer solution,
taking into account the weight of the polymer and its concentration in this solution, is proposed. The
influence of a polymer additive in such a solution on the turbulent diffusion and the redistribution of turbulent
energy between the Reynolds-stress tensor components was numerically investigated. It is shown that a
high-molecular-weight polymer additive in the indicated flow plays a crucial role in changing the intensity of
the energy exchange between the turbulent-stress components, which manifests itself as an increase in the anisotropy
of the solution and a decrease in the turbulent-energy production and leads to a decrease in the friction
drag in the flow.
Keywords: polymer solution, turbulent boundary layer, friction drag, Toms effect, Reynolds-stress tensor.
HEAT AND MASS TRANSFER IN COMBUSTION PROCESSES SIMPLIFIED APPROACH TO THE SIMULATION OF DETONATION WAVES IN GASES
E. S. Prokhorov
The possibility of simulation of gas-detonation products by an isothermal medium was considered. It is shown
that the simplified approach proposed for simulation of the propagation of detonation waves makes it possible,
in a number of cases, to approximate the results of numerical calculations of detonation-product flows by
analytical dependences with an accuracy sufficient for practical purposes.
Keywords: detonation waves, degree of overcompression of a detonation wave, detonation products, isothermal
VIBRATION COMBUSTION AS A PROSPECT FOR UTILIZING FIREWOOD CONTAMINATED WITH RADIOCESIUM
Yu. V. Polezhaev,a V. D. Geshele,a I. P. Raskatov,a
V. N. Solov’ev,b I. G. Pleshchankov,b L. A. Bida,b
A. S. Levchuk,b and G. I. Fokinab
We present results of experimental investigation relevant to vibration combustion of solid fuel specimens in a
Rijke tube and the interpretation of the combustion mechanism on the basis of "energy" approach. The decrease
in the flame temperature is noted, which can be used to reduce the yield of low-boiling mineral components
of ash, e.g., radioactive 137Cs isotope, in the volatile phase. The distribution of 137Cs in thermal
conversions of firewood has been studied with the aid of computational-experimental methods, and the use of
vibration combustion for utilizing the firewood contaminated with radiocesium has been suggested to decrease
the emission of 137Cs into the surrounding medium.
Keywords: vibration combustion, Rijke tube, solid fuel, radioactive isotopes.
SELF-OSCILLATIONS OF AN UNSTABLE FUEL COMBUSTION IN THE COMBUSTION CHAMBER OF A LIQUID-PROPELLANT ROCKET ENGINE
V. V. Gotsulenkoa and V. N. Gotsulenkob
The form of the self-oscillations of a vibrating combustion of a fuel in the combustion chamber of a liquidpropellant
rocket engine, caused by the fuel-combustion lag and the heat release, was determined. The character
of change in these self-oscillations with increase in the time of the fuel-combustion lag was investigated.
Keywords: relaxation self-oscillations of vibrating combustion, degenerate system, fuel-combustion lag, negative
CHART OF COMBUSTION REGIMES, SIMILARITY NUMBERS, AND TURBULENCE INVARIANTS
Yu. V. Polezhaev and G. V. Gabbasova
UDC 536.461; 536.25
A method for determining the height of a diffusional turbulent flame based on dimensional analysis, including
consideration of two independent nondimensional parameters of combustion, is suggested.
Keywords: combustion, flare, turbulent jets, fuel mixture, charts of combustion regimes.
GENERAL PROBLEMS OF TRANSPORT THEORY STRESSED STATE OF CHEMICALLY ACTIVE POLYMERIC
SYSTEMS UNDER SHEAR, ELONGATION, AND OSCILLATING DEFORMATIONS
V. I. Popov
The stressed state of chemically active polymeric systems under the conditions of shear, elongation, and oscillating
deformations has been investigated. From the viewpoint of locally nonequilibrium thermodynamics
and statistical physics for systems with a complex internal structure, the moment characteristics of the locally
nonequilibrium transfer process and the related components of their stress tensor deviator have been established.
The influence of deformation conditions on the amount and character of the change in the stressed
state of chemically active polymeric systems has been analyzed.
Keywords: stresses, polymers, relaxation, mechanoactivation, shear, elongation, and oscillating regimes of deformation.
ELECTRODYNAMICS OF ADSORPTION PROCESSES IN CONDENSED MEDIA
V. V. Leonov, M. Yu. Dolomatov, and T. A. Ismagilov
Electrodynamic approaches to describing adsorption processes on a solid surface in condensed physicochemical
systems are presented. Theoretical continuous consideration of the indicated processes showed that the
possibilities of direct electrometry of the properties of substances in a condensed state and of adsorbing
media can be increased considerably.
Keywords: condensed media, physicochemistry of adsorption, chemical potential, boundary-value problem of
electrodynamics, boundary conditions of electrometry.
HEAT CONDUCTION AND HEAT TRANSFER IN TECHNOLOGICAL PROCESSES THERMOLOGGING PROBLEM WITH A GIVEN RADIAL OIL-VELOCITY PROFILE IN THE WELL SHAFT
A. I. Filippov, O. V. Akhmetova, M. A. Zelenova,
and A. S. Rodionov
With the use of the asymptotic method the thermologging problem with a given radial oil-velocity profile is
presented in the form of a sequence of simpler problems containing different types of equations for corresponding
expansion coefficients, remainder term, and boundary-layer functions. Analytical expressions for the
zeroth and first expansion coefficients and boundary-layer functions taking into account the arbitrary radial
oil-velocity profile have been constructed. It has been shown that the derived asymptotic formula makes the
perturbation sources vanish in the averaged problem for the remainder term.
Keywords: temperature field, well, radial velocity profile, asymptotic method.
MODELING OF COOLING OF A STEEL-TEEMING LADLE
A. V. Zabolotskii
A mathematical model of formation of temperature fields in linings of metallurgical equipment is proposed,
which is based on the finite-element method and specific features of heat transfer on elements of this equipment.
The model is used to study temperature fields in the lining of a steel-teeming ladle under various operating
conditions. The model is verified experimentally with the example of a steel-teeming ladle cooled after
the metal is treated; the experimental verification shows that calculated temperature values at check points
are in accord with experimental temperatures.
Keywords: temperature field, steel-teeming ladle, lining, heat transfer, mathematical model.
MATHEMATICAL MODELING AND INVESTIGATIONS OF THE PROCESSES OF HEAT CONDUCTION OF AMMONIUM
PERCHLORATE WITH PHASE TRANSITIONS IN THERMAL DECOMPOSITION AND GASIFICATION
A. V. Mikhailov, I. M. Lagun, and E. P. Polyakov
Transient heat-conduction processes occurring in the period of thermal decomposition and gasification of a
crystalline oxidant — ammonium perchlorate — have been investigated and analyzed on the basis of the developed
Keywords: ammonium perchlorate, gasification, phase transition of the 2nd kind.
NUMERICAL SIMULATION OF THE FORMATION OF A TOXIC CLOUD ON OUTPOURING EJECTION OF LIQUEFIED
CHLORINE TO THE ATMOSPHERE
A. D. Galeev, E. V. Starovoitova, and S. I. Ponikarov
The results of numerical investigation of the influence of wind velocity and degree of atmospheric stability on
the process of toxic cloud formation on outpouring ejection of liquefied chlorine are presented. The computational
procedure is realized with the use of the hydrodynamic analysis package FLUENT. The proposed
model describes the distribution of two clouds: primary and secondary. The primary aerosol cloud is formed
as a result of instantaneous boiling up of a part of the liquid phase, and the secondary one, on evaporation
(boiling) of a spill.
Keywords: emergency ejection, liquefied chlorine, vaporization, gas propagation, numerical simulation.
EVOLUTIONARY TRANSFORMATION OF COMMUNAL THERMAL-POWER ENGINEERING
A. I. Nakorchevskii
A solution is given to the problem of heat supply to multi-storied residential and office buildings with the use
of solar insolation as the principal energy source making it possible to do away with the district heating of
towns and settlements and to reduce expenditure of energy on heating and hot water supply by more than
Keywords: accumulator, buffer, house, hot water supply, ground, collector, heating, radiation, Sun, heat transfer,
heat pump, ecology, economics.
MISCELLANEA STRIPLINE-TYPE PHOTODETECTOR BASED ON THE NARROW-GAP TERNARY COMPOUND
Hg1−xCdxTe FOR THE FAR IR REGION
Ya. I. Lepikh, I. A. Ivanchenko, and L. M. Budiyanskaya
Consideration has been given to the problem of creation of an uncooled semiconductor photodetector sensitive
in the far infrared region. The possibility of creating an uncooled semiconductor photodetector with a
strip-waveguide structure on the basis of the narrow-gap ternary compound Hg1−xCdxTe that takes advantage
of the wave properties of light to record radiation in the far infrared region has been substantiated.
Keywords: uncooled semiconductor photodetector, stripline, waveguide.
FEATURES OF THE TEMPERATURE PROPERTIES OF A FIELD-EFFECT TRANSISTOR IN A CURRENT-LIMITING MODE
O. A. Abdulkhaev, D. M. Yodgorova, A. V. Karimov,
B. M. Kamanov, and A. A. Turaev
A study has been made of the physical processes in a field-effect transistor when its thermosensitive parameters,
such as the direct voltage of the gate p–n junction and the cutoff voltage of the channel, are acted upon
by temperature. It has been established experimentally that one can control the temperature-sensitivity coefficient
of a diode-connected field-effect transistor.
Keywords: field-effect transistor, temperature, dropping voltage, current limiting.
Comments on the Paper "A Study of Induced Magnetic Field with Chemically Reacting and Radiating
Fluid past a Vertical Permeable Plate" by S. Ahmed – Bhupendra Kumar Sharma