VOLUME 85, NUMBER 3

HEAT AND MASS TRANSFER IN DISPERSE AND POROUS MEDIA

COALESCENCE OF AN ENSEMBLE OF NANOPARTICLES IN
A FEMTOLITER DROPLET OF SUPERSATURATED SOLUTION
S. P. Fisenko and Yu. A. Khodyko

UDC 536.423
A numerical analysis of coalescence and growth of an ensemble of nanoparticles on colloid precursors in a
femtoliter droplet was carried out. It is shown that the supersaturation of a solution inside the droplet occurs
due to the evaporative cooling of droplets in an aerosol reactor at a lowered pressure. It has been proved
that in the medium field approximation, particles grow stably only on largest precursors. At short times the
distribution function of nanoparticles is of more complex character.
Keywords: diffusion, medium field approximation, Kelvin effect.

PAGE 487

INFLUENCE OF MAGNETIC AND ACOUSTIC TREATMENT
OF SUPERPLASTICIZER SOLUTIONS ON THE PROPERTIES
OF PORTLAND CEMENT CONCRETES
N. Kh. Belous,^a V. V. Azharonok,^b S. P. Rodtsevich,^a
V. D. Koshevar,^a S. V. Goncharik,^b N. I. Chubrik,^b
A. I. Orlovich,^c and V. V. Rubannik^d
UDC 666.97.001.015:[53.09+53.06]
We have investigated the influence of the regimes of high-frequency magnetic-impulse and acoustic action on
the physicochemical properties of water solutions of polycarboxylate superplasticizers and technological indices
of fine concretes plasticized by them. The dependences of technological properties of concretes on the
concentration of water solutions of the superplasticizers, the content of impurity ions in the water used for
dilution, and the conditions of acousto-radiowave treatment have been determined. The regimes of activation
of superplasticizer solutions, which permit increasing the mobility and keeping quality of concrete and solution
mixes tempered with water and the density and strength of fine concretes formed from them, have been
established.
Keywords: tempering liquid, superplasticizers, electromagnetic and acoustic activation, portland cement, concretes,
density, compression strength, mobility, index of activity of hydrogen ions, surface tension, shear stress,
dynamic viscosity.

PAGE 493

OBTAINING CARBON SUSPENSIONS
BY THE HYDROMECHANICAL METHOD
O. G. Martynenko, A. A. Bulavko, A. V. Suvorov,
A. V. Vlasov, L. A. Senchuk*, and M. I. Rusakevich
UDC 536.46
This paper presents the results of an investigation of the process of obtaining carbon suspensions with a fraction
of carbon particles of size less than a micrometer by the hydromechanical method with the use of a
gear-type pump and two rotor-type pulsation pulverizers.
Keywords: coal-water slurry, hydromechanical treatment, cavitation.

PAGE 501

MODELING OF THE PROCESS OF TWO-PHASE
TRANSPIRATION COOLING IN THE PRESENCE
OF PERIODIC PERTURBATIONS
A. N. Golovanov and A. S. Yakimov

UDC 536.46:536.245.022
Consideration is given to the interaction between a system of two-phase transpiration cooling and a high-enthalpy
pulsating gas flow. A study is made of the influence of the process of phase transformation on the
characteristics of heat and mass exchange and on the possibility of controlling the process of heat exchange
in a thermal protective material.
Keywords: two-phase cooling, thermal protective material, pulsating gas flow, heat and mass exchange.

PAGE 505

ON CALCULATION OF FILTRATION FLOWS
FROM SPRAYERS OF IRRIGATION SYSTEMS
E . N. Bereslavskii

UDC 532.546
In the hydrodynamic formulation, consideration is given to plane steady filtration in a homogeneous isotropic
ground from sprayers through a soil layer underlain by a highly permeable pressure water-bearing formation
in the presence of the ground capillarity and evaporation from the free surface. Filtration is studied by formulating
a mixed multiparametric boundary-value problem of the theory of analytical functions, which is
solved using the Polubarinova-Kochina method and procedures of conformal mapping of the regions of special
kind that are characteristic of underground-hydromechanics problems. On the basis of the model proposed,
an algorithm of computation of capillary water spread and filtration flow rate was developed in
situations where in the water filtration from sprayers, account is taken of the ground capillarity, evaporation
from the free surface, and of the upthrust from the side of the underlying well-permeable formation. With the
aid of the exact analytical dependences obtained and of numerical calculations, a hydrodynamic analysis is
performed for the structure and characteristic features of the modeled process, and for the influence of all
physical parameters of the scheme on the filtration characteristics. Consideration is given to the limiting and
particular cases associated with the absence of separate factors characterizing the modeled process, such as
the ground capillarity, evaporation from the free surface, and the upthrust from the side of the underlying
water-bearing highly permeable layer. Calculated results for filtration from canals with identical filtration
characteristics and similar filtration schemes are compared.
Keywords: filtration, sprayer, groundwater, pressure underground water, ground capillarity, evaporation from
the free surface, complex flow velocity, conformal mappings, Polubarinova-Kochina method.

PAGE 516

HEAT EXCHANGE IN A RING GRANULAR BED
Yu. S. Teplitskii and M. V. Vinogradova

UDC 532.546
On the basis of a theoretical model of heat exchange in a granular bed, a simple dependence has been obtained
for calculation of the heat-exchange coefficient in an extended ring bed. A comparison the dependence
and the available experimental data has been made.
Keywords: ring granular bed, heat-exchange coefficient, model of heat exchange, active heat insulation, air
heater.

PAGE 539

HYPERBOLIC MODEL OF A MULTIVELOCITY
HETEROGENEOUS MEDIUM
V. S. Surov

UDC 532.529.5
The model of a multivelocity multicomponent medium, which is based on the conservation laws and whose
equations belong to a hyperbolic type, has been presented. A number of problems on disintegration of an arbitrary
discontinuity in a dust-laden gas have been calculated with the Courant–Isaacson–Rees numerical
method.
Keywords: multicomponent multivelocity medium, hyperbolic systems of partial differential equations, numerical
modeling.

PAGE 530

NANOSTRUCTURES
HEAT AND MASS TRANSFER IN THE SYSTEM
HYDROCARBON GAS–POROUS CARBON LAYER–METAL
AND FORMATION OF SUPERSATURATED SOLID CARBON
SOLUTIONS
D. A. Takopulo and S. P. Fisenko

UDC 536.248
It is shown that the carbon layer formed on the catalytic surface of a metal plays an important role in industrial
technologies of obtaining carbon nanofibers. The effective heat conduction of porous carbon samples
was measured. A mathematical model of the heat and mass transfer inside a carbon layer has been developed
and its stationary solutions were investigated. It is shown that a decrease in the thickness of a porous carbon
layer on the surface of a metal as a result of its cleaning and a further growth of this layer lead to the formation
of a supersaturated solid solution of carbon in the metal.
Keywords: effective heat conduction of a porous layer, diffusion of carbon, time of establishment of a stationary
regime, Pade′ approximation, solubility of carbon in a metal.

PAGE 539

PYROLYSIS OF A FEMTOLITER DROP
IN A LOW-TEMPERATURE AEROSOL
REACTOR AT A LOWERED PRESSURE
K. I. Delendik, V. I. Saverchenko,
and S. P. Fisenko
UDC 536.423
The products of low-temperature pyrolysis of a solute in the rapid evaporation of droplets of an aqueous solution
of NiCl2 in an aerosol reactor, were found experimentally. An x-ray spectroscopic analysis has shown
that approximately 37% of nickel atoms pass into oxides. The pyrolysis products possess residual magnetization.
It is also found that the rate of evaporation of nickel and chlorine compounds depends on the radius of
droplets and their mass flow rate.
Keywords: evaporation, nanoparticles, nickel oxide, supersaturated solution, galvanoplastics, x-ray spectroscopic
analysis.

PAGE 549

HEAT AND MASS TRANSFER IN COMBUSTION PROCESSES
ON THE POSSIBILITY OF ENHANCING
THE RATE OF COMBUSTION OF GASES
AND GASEOUS MIXTURES
Yu. V. Polezhaev, O. G. Stonik,
and G. V. Gabbasova
UDC 536.461; 536.25
A classification of combustion regimes is given. The influence of various factors on the combustion rate and
height of a flame is shown. Relationships for determining the rates of laminar and turbulent combustion of a
fuel are given.
Keywords: combustion regimes, flame height, scale of turbulent combustion.

PAGE 554

METHOD FOR CHARACTERIZING AND CHOOSING
THE SOLID MIXED FUEL FOR MICROTHRUSTERS
OF MICROELECTROMECHANICAL SYSTEMS
S. I. Futko,^a V. P. Bondarenko,^b,
and L. N. Dolgii^b
UDC 662.612.2.662.311.1
We propose a method for characterizing and choosing solid mixed fuels for use as the solid-fuel charge of
microthrusters of microelectromechanical systems. The method is based on the solution of the problem on the
dependence of impulse responses of such a microthruster on the diameter of the outlet cross-section of its
combustion chamber and the microkinetic parameters of the fuel. The variants of choosing the above fuels
have been illustrated using glycidyl azide polymer/RDX as the example of a solid fuel mixture. The paper presents
the characteristic criteria determining the composition of mixed fuels for the microthruster of a microelectromechanical
system and considers the main types of "direct" and "inverse" problems arising in
characterizing and choosing such fuels.
Keywords: solid rocket fuel, solid fuel combustion, macrokinetic modeling, solid-fuel rocket engine, microthruster,
thermodynamics, mixed fuel, solid-fuel charge, glycidyl azide polymer, RDX, method, impulse.

PAGE 558

MODELING OF THE PROCESS OF BURNING-OUT
OF COKE–ASH PARTICLES IN A FLUIDIZED BED
B. B. Rokhman UDC 532.529:532.517.4
A generalized statistical model of the process of burning out of coal particles in a fluidized-bed furnace is
constructed. It takes into account the kinetics of heterogeneous chemical reactions, as well as radiant and
convective–conductive heat transfer, which made it possible to considerably expand the region of application
of the existing models. Different schemes of the behavior of ash in the process of burning of carbon particles
are considered. Boundary conditions (conditions of matching) were formulated, and analytical solutions for
the distribution function of particles in small intervals of carbon concentration for surface and bulk reaction
have been obtained.
Keywords: distribution function, combustion, particle, gas, polydispersity, temperature, heterogeneous reaction,
concentration, velocity, aerodynamics, fluidized bed.

PAGE 565

MICROWAVE TECHNOLOGIES IN COAL POWER ENGINEERING
V. V. Salomatov,^a,c S. O. Sladkov,^b
and S. E′. Pashchenko^c
UDC 621.311
An analysis of the modern state and prospects of using microwave radiation in the processes of drying, dispersion,
burning, and fine processing of low-rank coals for the purpose of increasing the energy efficiency of
coal technologies and decreasing harmful emissions from them has been carried out. It is shown that the use
of microwave-radiation energy in coal power engineering is a promising method of complex action on coal in
the process of its preparation and burning.
Keywords: microwave radiation, coal, drying, heating, dispersion, cleaning, ignition, burning, processing.

PAGE 576

TRANSFER PROCESSES IN A LOW-TEMPERATURE PLASMA
INFLUENCE OF CLUSTERING ON THE EFFECTIVE
ADIABATIC EXPONENT OF A LOW-TEMPERATURE
CARBON PLASMA
N. I. Alekseev,^a,b B. I. Reznikov,^a B. G. Zhukov,^a
S. V. Bobashev,^a S. A. Ponyaev,^a and R. O. Kurakin^a
UDC 532.525, 537.523
Calculation of the equilibrium composition and the effective adiabatic exponent of a low-temperature carbon
plasma containing neutral and charged carbon clusters up to the clusters C15 has been carried out. The
range of temperatures and pressures at which carbon atoms associate into multiatomic clusters has been determined.
It has been shown that the effective adiabatic exponent of carbon plasma is a composite nonmonotonic
function of temperature, which has a substantial effect on the flow of a carbon-plasma jet out of
channels and on plasma-flux flow past various obstacles.
Keywords: railtron, rail accelerator, plasma jet, carbon clusters.

NUMERICAL MODELING OF ARC PLASMA
GENERATOR FOR CHEMICAL LASER APPLICATIONS
Vidya Sagar,^a Chhaya Ravikant,^b
Gaurav Singhal,^a and Alok P. Mittal^c
UDC 535.2/.3+621.375
The results of the numerical modeling of arc discharge phenomenon relevant to hydrogen fluoride/deuterium
fluoride (HF/DF) laser applications are given. The overall mechanics of arc discharge phenomena on the
basis of numerical modeling employing the commercial code COMSOL is discussed. The equations for a 2D
axisymmetric, weakly compressible, laminar flow with heat transfer and the coupled hydrodynamic and electromagnetic
equations are solved using the SIMPLE algorithm. The variations in the material properties, temperature,
and velocity due to the generated arc are studied. A comparison of the results obtained with those
from the studies available in the literature validates the computational data. Since each designed plasma arc
tunnel is unique in itself and specific in application, this would enable one to alter arc discharge parameters
to optimize a specific laser.
Keywords: HF/DF, arc plasma generator, COMSOL.

PAGE 605

HYDROGASDYNAMICS IN TECHNOLOGICAL PROCESSES

MODELING OF REFLECTION OF DETONATION
AND SHOCK WAVES FROM A RIGID WALL
IN MIXTURES OF A REACTIVE GAS
AND CHEMICALLY INERT PARTICLES
A. V. Fedorov,^a P. A. Fomin,^b
D. A. Tropin,^a and J.-R. Chen^c
UDC 534.222
An algorithm of approximate calculation of the reflection of detonation waves in mixtures of a reactive gas
and chemically inert microparticles has been proposed. Consideration has been given to the case where the
gas behind the wave front is in chemical equilibrium (D → D reflection). It has been shown that the presence
of the condensed phase can substantially decrease the parameters of the reflected wave (its velocity, pressure,
and temperature). Within the framework of a one-dimensional nonstationary approach and with allowance for
the detailed kinetics of chemical reactions, the evolution of the shock wave in a stoichiometric hydrogen-oxygen
mixture with sand particles in its reflection from a rigid wall has been calculated. The limiting particle
concentration below which the reflected wave is of the detonation type and above which it is of the shock
type has been found.
Keywords: suppression of gaseous detonation, gas-particles mixture, explosion safety.

PAGE 614

NUMERICAL SIMULATION OF THE SELF-ORGANIZATION
OF CONVECTIVE STRUCTURES IN A THIN LAYER OF LIQUID
I. N. Shishkova, V. Yu. Levashov,
and A. P. Kryukov
UDC 532.527
Complex convective structures observed experimentally in a thin layer of liquid are investigated numerically.
To study this kind of phenomena, a mathematical model is suggested based on the interaction of two such opposite
factors as the randomness of convective motions in the medium of interest as a whole and intensification
of these motions by local sources that introduce correlations into a random process. The results obtained
by mathematical simulation qualitatively reflect the most characteristic phenomena noted in the experiments.
Keywords: convective structures, numerical simulation, thin liquid layer.

CONDUCTION–CONVECTION–RADIATION EFFECTS
ON THE FLOW OF OPTICALLY DENSE GRAY FLUID
OVER A HORIZONTAL CIRCULAR DISK
S. Siddiqaa and M. A. Hossainb

UDC 536.25
A natural convection boundary-layer flow of an optically dense gray viscous fluid (liquid metal) above a horizontal
circular disk with regard to thermal radiation is discussed. The radiative heat flux term is expressed
by using the optically thick radiation limit. The corresponding boundary-layer equations are solved with the
aid of three distinct numerical techniques: the straightforward finite difference (SFD) method is employed to
solve the problem directly, and then the stream function formulation (SFF) and primitive variable formulation
(PVF) methods based on solving transformed equations are used. The numerical results are interpreted in
terms of the local skin friction coefficient and the local Nusselt number. The influence of the problem parameters
on these characteristics is shown.
Keywords: natural convection, thermal radiation, horizontal circular disk.

LOCAL THEORY OF PARALLEL APPROACH
OF PLATES IN AN INCOMPRESSIBLE LIQUID
S. K. Betyaev

UDC 532.526.2
A flow of an incompressible liquid in a thin layer between two approaching disks or plates located in parallel,
at the final stage of their symmetrical approach, is considered. It is assumed that the velocity of the body
is assigned as a function of time. An inspection analysis of the problem has been made: the types of flows
depending on the law of approaching plates and the conditions under which the pressure in the layer and,
consequently, the acting forces increase infinitely have been determined. Approximate solutions in the plane
and axisymmetric cases are suggested. Exact solutions have been obtained for infinitely small and infinitely
high Reynolds numbers.
Keywords: incompressible liquid, law of approaching plates, viscous flow regime, highly viscous flow regime,
inviscid flow regime.

STERNBERG–KOITER PARADOX IN
PROBLEMS ON INVISCID FLOW OF FLUID
S. K. Betyaev

UDC 532.526.5
The problem on inviscid flow of fluid inside a wedge when the Sternberg–Koiter paradox takes place has
been considered. The flow is divided into potential and vortex and stationary and nonstationary ones. A resolution
of the paradox is given.
Keywords: singularity, bifurcation, self-similarity, superposition.

SOME TWO-DIMENSIONAL FLOWS WITH COUPLE STRESSES
M. Sajid,a N. Ali,b Z. Abbas,b
T. Javed,b and M. Imranc
UDC 532.5
The effect of couple stresses on some two-dimensional flows is considered. The numerical solutions are obtained
by the shooting method using the Runge–Kutta algorithm in the four flow problems for a couple stress
fluid, namely, for the Blasius, Sakiadis, stretching, and stagnation-point flows. The obtained solutions are nonsimilar
for the Blasius and Sakiadis flows. The results are interpreted concerning the influence of the couple
stress parameter which is a measure of the polarity of a fluid. It is shown that for large values of this parameter
the solution converges to the solution for a Newtonian fluid.
Keywords: two-dimensional flow, couple stresses, Blasius flow, Sakiadis flow, stretching flow, stagnation-point
flow, numerical solution.

TRANSFER PROCESSES IN RHEOLOGICAL MEDIA
RHEOLOGY DYNAMICS OF THE BLOOD AND PLASMA
OF RATS AFTER TRANSDERMAL LASER IRRADIATION
OF THE TAIL VEIN IN THE INFRARED RANGE
I. V. Yamaikina,a V. A. Mansurov,b N. B. Gorbunova,c
L. E. Batai,d V. S. Ulashchik,c and V. A. Orlovichd
UDC 577.344.3
Single transdermal laser irradiation of the tail vein of males of white mongrel rats with an average mass of
350–400 g in three different regimes has been carried out. The irradiation doses were chosen to be intermediate
between therapeutic and surgical ones, and the radiation wavelengths were 806 nm and 2 μm. The dynamics
of the packed cell volume, deformability and cytometric indices of erythrocytes, and of the plasma and
blood viscosity have been investigated. The rheological and cytometric changes in the blood caused by the irradiation
stayed for several days. The observed rheologial changes are due to the removal of irradiation-damaged
erythrocytes and the arrival in the blood channel of young and highly deformable red cells.
Keywords: viscosity, blood, plasma, deformability of erythrocytes, infrared spectral range, laser irradiation.

RHEOLOGICAL PROPERTIES OF DISPERSE SYSTEMS
BASED ON HYDROLYZED LIGNIN AND OIL
T. A. Savitskaya,a I. V. Reznikov,a V. A. Shcheglov,a
N. G. Tsygankova,b G. M. Telysheva,c and D. D. Grinshpanb
UDC [66.081.3+665.7]:634.0.864
The rheological properties of oil dispersions of hydrophobized hydrolyzed lignin, which is an effective sorbent
of oil and oil products, have been studied. It has been shown that at a lignin concentration of over 10%,
free-disperse systems with Newton flow go over to coagulation thixotropic structures, demonstrating the
pseudoplastic character of flow. The structural-mechanical characteristics of highly filled (lignin content of
40–45%) dispersions have been determined and the concentration region of existence of an oil-saturated sorbent
in the form of a solid product easily removed from the water surface has been established.
Keywords: rheological properties, oil, lignin, dispersion.

MATHEMATICAL MODELING OF THE FORMATION
OF CLOTS IN BLOOD VESSELS
E ′
. M. Khramchenkov and M. G. Khramchenkov UDC 532.546
A mathematical model of the formation of a clot (thrombosis) has been constructed in which the fibrin of the
clot is considered as an elastically deformable solid phase of variable mass and the prothrombin, thrombin,
fibrinogen, and fibrin monomers as components of the liquid phase. As a result of numerical solution of the
model, data on the influence of various parameters of the process of thrombosis on the rate of clot formation
have been obtained.
Keywords: blood vessels, clot, thrombosis, vessel wall, thrombin, prothrombin, fibrinogen, fibrin network.

HEAT CONDUCTION AND HEAT EXCHANGE IN TECHNOLOGICAL PROCESSES
ON THE INFLUENCE OF ASYMMETRY ON THE VELOCITY
OF MOTION OF ISOTHERMS NEAR THE THERMAL CENTER
OF A COOLED BODY
V. V. Vinogradov,a I. L. Tyazhel’nikova,a
and E. P. Vinogradovab
UDC 536.2
A study has been made of the influence of asymmetric cooling of bodies due to the temperature difference on
the surfaces, the difference in thermophysical characteristics of the media, and the geometry of the body on
the velocity of motion of isotherms as they approach the thermal center. The results have been used for elucidation
of the causes of certain thermophysical features appearing when continuously cast ingots solidify in
horizontal continuous casting plants and when the bloom molds are replaced by slab molds in continuous
ingot casting machines. An analytical expression for the displacement of the thermal center of a plate in formation
of media with different thermal-diffusivity coefficients has been obtained.
Keywords: cooling of an ingot, velocity of motion of isotherms, thermal center, asymmetry, heat-conduction
equation, solidification of a continuously cast ingot, thermal diffusivity.

ANISOTROPY OF THERMAL CONDUCTIVITY
OF FERRO-FILLED POLYVINYLCHLORIDE
B. B. Kolupaev UDC 541.64:532.72
The contribution of the constant external magnetic field to the anisotropy of thermal conductivity of polyvinylchloride
(PVC) containing powders of highly dispersed ferromagnetics (iron and magnetite) as a filler has
been determined. The relationship between the thermal conductivity coefficient of such PVCs, the direction of
the heat-flux vector, and the normal to the isotherm of the composite has been established. It has been shown
that for the systems "PVC + 2.0 vol. % Fe" and "PVC + 2.0 vol. % Fe3O4" formed on exposure to an external
magnetic field, the value of the principal axes of the thermal-conductivity coefficient depends on the
type of filler. A comparison of the calculated and experimental values of the sought quantities has been made.
Keywords: anisotropy, magnetite, heat conduction, heat flux.

TOWARDS THE DYNAMICS OF THE TEMPERATURE FIELD
GRADIENT IN A LAYER OF AN INORGANIC MATERIAL
UNDER RADIATION HEATING ACCORDING TO THE DATA
OF EXPERIMENTS AND NUMERICAL MODELING
V. R. Sobol,a P. N. Goman,b
and O. N. Mazurenkoc
UDC 536.331
We have investigated the process of temperature field formation in a layer of a weakly conducting medium
with the example of wood and green moss under irradiation of one side with an energy flux and contact heat
removal through the opposite back surface of the material onto an asbestos-cement support. The experimental
results were compared with the data calculated on the basis of the relations of nonstationary heat transfer in
the approximations of closeness and openness of the system. The conditions for heat removal suppression have
been concretized and the role of the energy exchange under the prolonged action of radiant energy for estimating
the thermal stability parameters of related materials has been elucidated. The obtained data can be
used to control radiant fluxes in treating wood, for effective heating of living and industrial premises, improving
the methods for opposing high energy fluxes, and preventing the propagation of fire in inhabited localities
and in park and forest zones.
Keywords: temperature, temperature gradient, heat flow, heat conductivity, heat capacity, heating, heat removal,
green moss, flammability.

THERMAL AND NEUTRON-PHYSICAL FEATURES
OF THE NUCLEAR REACTOR FOR A POWER
PULSATION PLANT FOR SPACE APPLICATIONS
E ′
. G. Gordeev,a A. S. Kaminskii,a G. V. Konyukhov,b
V. A. Pavshuk,b and T. A. Turbinaa
UDC 621.039.5
We have explored the possibility of creating small-size reactors with a high power output with the provision
of thermal stability and nuclear safety under standard operating conditions and in emergency situations. The
neutron-physical features of such a reactor have been considered and variants of its designs preserving the
main principles and approaches of nuclear rocket engine technology are presented.
Keywords: nuclear power plant, nuclear rocket engine, modular design, energy production, thermal stability,
nuclear safety, reactivity effects, burnable neutron poison, fission density.

INVESTIGATION OF THE PHOTOELECTRIC
CHARACTERISTICS OF PHOTODIODE STRUCTURES
WITH SILICON-BASED POTENTIAL BARRIERS
O. A. Abdulkhaev, G. O. Asanova,
D. M. Yodgorova, and A. V. Karimov
UDC 621.383.52:535.243
Based on silicon with a base region thickness of 300 μm, phototransforming Au–nSi–Au structures with potential
barriers are prepared. The diode structures obtained possess high photosensitivity in the spectral region
0.9–1.1 μm at low illumination intensities of 10 lux (up to 5 A/W). Based on investigations of the
photoelectric characteristics, it has been established that the Au–nSi–Au structures in the range of temperatures
from room temperature to 40oC at low working voltages (0.1–0.2 V) are distinguished by the weak temperature
dependence of photocurrents. In principle, in the spectral range 0.7–1.1 μm the Au–nSi–Au
structures obtained can easily replace both gallium arsenide and classical silicon photodiodes with one rectifying
junction in optoelectronic devices.
Keywords: photoelectric characteristics, photocurrent, potential barriers, base region, silicon, photodiode structure.

REFLECTIONLESS TRANSMISSION OF ELECTROMAGNETIC
RADIATION THROUGH A MAGNETIC–DIELECTRIC SYSTEM
G. A. Mamedov, E′. G. Ismibeili,
and S. R. Kasimova
UDC 621.365
The conditions and frequency band of reflectionless transmission of electromagnetic radiation through a plane
absorbing layer of a magnet that separates two semi-infinite nonabsorbing dielectric media have been found.
The dependence of these conditions on the separating layer thickness, magnetic and dielectric properties of
the layer substance, and of the adjacent substrate is investigated.
Keywords: absorption of electromagnetic wave, magnetic coating, dielectric substrate.

HEAT AND MASS TRANSFER IN DISPERSE AND POROUS MEDIA
COALESCENCE OF AN ENSEMBLE OF NANOPARTICLES IN
A FEMTOLITER DROPLET OF SUPERSATURATED SOLUTION
S. P. Fisenko and Yu. A. Khodyko UDC 536.423
A numerical analysis of coalescence and growth of an ensemble of nanoparticles on colloid precursors in a
femtoliter droplet was carried out. It is shown that the supersaturation of a solution inside the droplet occurs
due to the evaporative cooling of droplets in an aerosol reactor at a lowered pressure. It has been proved
that in the medium field approximation, particles grow stably only on largest precursors. At short times the
distribution function of nanoparticles is of more complex character.
Keywords: diffusion, medium field approximation, Kelvin effect.

INFLUENCE OF MAGNETIC AND ACOUSTIC TREATMENT
OF SUPERPLASTICIZER SOLUTIONS ON THE PROPERTIES
OF PORTLAND CEMENT CONCRETES
N. Kh. Belous,a V. V. Azharonok,b S. P. Rodtsevich,a
V. D. Koshevar,a S. V. Goncharik,b N. I. Chubrik,b
A. I. Orlovich,c and V. V. Rubannikd
UDC 666.97.001.015:[53.09+53.06]
We have investigated the influence of the regimes of high-frequency magnetic-impulse and acoustic action on
the physicochemical properties of water solutions of polycarboxylate superplasticizers and technological indices
of fine concretes plasticized by them. The dependences of technological properties of concretes on the
concentration of water solutions of the superplasticizers, the content of impurity ions in the water used for
dilution, and the conditions of acousto-radiowave treatment have been determined. The regimes of activation
of superplasticizer solutions, which permit increasing the mobility and keeping quality of concrete and solution
mixes tempered with water and the density and strength of fine concretes formed from them, have been
established.
Keywords: tempering liquid, superplasticizers, electromagnetic and acoustic activation, portland cement, concretes,
density, compression strength, mobility, index of activity of hydrogen ions, surface tension, shear stress,
dynamic viscosity.

MODELING OF THE PROCESS OF TWO-PHASE
TRANSPIRATION COOLING IN THE PRESENCE
OF PERIODIC PERTURBATIONS
A. N. Golovanov and A. S. Yakimov UDC 536.46:536.245.022
Consideration is given to the interaction between a system of two-phase transpiration cooling and a high-enthalpy
pulsating gas flow. A study is made of the influence of the process of phase transformation on the
characteristics of heat and mass exchange and on the possibility of controlling the process of heat exchange
in a thermal protective material.
Keywords: two-phase cooling, thermal protective material, pulsating gas flow, heat and mass exchange.

ON CALCULATION OF FILTRATION FLOWS
FROM SPRAYERS OF IRRIGATION SYSTEMS
E ′
. N. Bereslavskii UDC 532.546
In the hydrodynamic formulation, consideration is given to plane steady filtration in a homogeneous isotropic
ground from sprayers through a soil layer underlain by a highly permeable pressure water-bearing formation
in the presence of the ground capillarity and evaporation from the free surface. Filtration is studied by formulating
a mixed multiparametric boundary-value problem of the theory of analytical functions, which is
solved using the Polubarinova-Kochina method and procedures of conformal mapping of the regions of special
kind that are characteristic of underground-hydromechanics problems. On the basis of the model proposed,
an algorithm of computation of capillary water spread and filtration flow rate was developed in
situations where in the water filtration from sprayers, account is taken of the ground capillarity, evaporation
from the free surface, and of the upthrust from the side of the underlying well-permeable formation. With the
aid of the exact analytical dependences obtained and of numerical calculations, a hydrodynamic analysis is
performed for the structure and characteristic features of the modeled process, and for the influence of all
physical parameters of the scheme on the filtration characteristics. Consideration is given to the limiting and
particular cases associated with the absence of separate factors characterizing the modeled process, such as
the ground capillarity, evaporation from the free surface, and the upthrust from the side of the underlying
water-bearing highly permeable layer. Calculated results for filtration from canals with identical filtration
characteristics and similar filtration schemes are compared.

Keywords: filtration, sprayer, groundwater, pressure underground water, ground capillarity, evaporation from
the free surface, complex flow velocity, conformal mappings, Polubarinova-Kochina method.

HEAT EXCHANGE IN A RING GRANULAR BED
Yu. S. Teplitskii and M. V. Vinogradova UDC 532.546
On the basis of a theoretical model of heat exchange in a granular bed, a simple dependence has been obtained
for calculation of the heat-exchange coefficient in an extended ring bed. A comparison the dependence
and the available experimental data has been made.
Keywords: ring granular bed, heat-exchange coefficient, model of heat exchange, active heat insulation, air
heater.

HYPERBOLIC MODEL OF A MULTIVELOCITY
HETEROGENEOUS MEDIUM
V. S. Surov UDC 532.529.5
The model of a multivelocity multicomponent medium, which is based on the conservation laws and whose
equations belong to a hyperbolic type, has been presented. A number of problems on disintegration of an arbitrary
discontinuity in a dust-laden gas have been calculated with the Courant–Isaacson–Rees numerical
method.
Keywords: multicomponent multivelocity medium, hyperbolic systems of partial differential equations, numerical
modeling.

NANOSTRUCTURES
HEAT AND MASS TRANSFER IN THE SYSTEM
HYDROCARBON GAS–POROUS CARBON LAYER–METAL
AND FORMATION OF SUPERSATURATED SOLID CARBON
SOLUTIONS
D. A. Takopulo and S. P. Fisenko UDC 536.248
It is shown that the carbon layer formed on the catalytic surface of a metal plays an important role in industrial
technologies of obtaining carbon nanofibers. The effective heat conduction of porous carbon samples
was measured. A mathematical model of the heat and mass transfer inside a carbon layer has been developed
and its stationary solutions were investigated. It is shown that a decrease in the thickness of a porous carbon
layer on the surface of a metal as a result of its cleaning and a further growth of this layer lead to the formation
of a supersaturated solid solution of carbon in the metal.
Keywords: effective heat conduction of a porous layer, diffusion of carbon, time of establishment of a stationary
regime, Pade′ approximation, solubility of carbon in a metal.

METHOD FOR CHARACTERIZING AND CHOOSING
THE SOLID MIXED FUEL FOR MICROTHRUSTERS
OF MICROELECTROMECHANICAL SYSTEMS
S. I. Futko,a V. P. Bondarenko,b
and L. N. Dolgiib
UDC 662.612.2.662.311.1
We propose a method for characterizing and choosing solid mixed fuels for use as the solid-fuel charge of
microthrusters of microelectromechanical systems. The method is based on the solution of the problem on the
dependence of impulse responses of such a microthruster on the diameter of the outlet cross-section of its
combustion chamber and the microkinetic parameters of the fuel. The variants of choosing the above fuels
have been illustrated using glycidyl azide polymer/RDX as the example of a solid fuel mixture. The paper presents
the characteristic criteria determining the composition of mixed fuels for the microthruster of a microelectromechanical
system and considers the main types of "direct" and "inverse" problems arising in
characterizing and choosing such fuels.
Keywords: solid rocket fuel, solid fuel combustion, macrokinetic modeling, solid-fuel rocket engine, microthruster,
thermodynamics, mixed fuel, solid-fuel charge, glycidyl azide polymer, RDX, method, impulse.

MICROWAVE TECHNOLOGIES IN COAL POWER ENGINEERING
V. V. Salomatov,a,c S. O. Sladkov,b
and S. E′. Pashchenkoc
UDC 621.311
An analysis of the modern state and prospects of using microwave radiation in the processes of drying, dispersion,
burning, and fine processing of low-rank coals for the purpose of increasing the energy efficiency of
coal technologies and decreasing harmful emissions from them has been carried out. It is shown that the use
of microwave-radiation energy in coal power engineering is a promising method of complex action on coal in
the process of its preparation and burning.
Keywords: microwave radiation, coal, drying, heating, dispersion, cleaning, ignition, burning, processing.

TRANSFER PROCESSES IN A LOW-TEMPERATURE PLASMA
INFLUENCE OF CLUSTERING ON THE EFFECTIVE
ADIABATIC EXPONENT OF A LOW-TEMPERATURE
CARBON PLASMA
N. I. Alekseev,a,b B. I. Reznikov,a B. G. Zhukov,a
S. V. Bobashev,a S. A. Ponyaev,a and R. O. Kurakina
UDC 532.525, 537.523
Calculation of the equilibrium composition and the effective adiabatic exponent of a low-temperature carbon
plasma containing neutral and charged carbon clusters up to the clusters C15 has been carried out. The
range of temperatures and pressures at which carbon atoms associate into multiatomic clusters has been determined.
It has been shown that the effective adiabatic exponent of carbon plasma is a composite nonmonotonic
function of temperature, which has a substantial effect on the flow of a carbon-plasma jet out of
channels and on plasma-flux flow past various obstacles.
Keywords: railtron, rail accelerator, plasma jet, carbon clusters.

NUMERICAL MODELING OF ARC PLASMA
GENERATOR FOR CHEMICAL LASER APPLICATIONS
Vidya Sagar,a Chhaya Ravikant,b
Gaurav Singhal,a and Alok P. Mittalc
UDC 535.2/.3+621.375
The results of the numerical modeling of arc discharge phenomenon relevant to hydrogen fluoride/deuterium
fluoride (HF/DF) laser applications are given. The overall mechanics of arc discharge phenomena on the
basis of numerical modeling employing the commercial code COMSOL is discussed. The equations for a 2D
axisymmetric, weakly compressible, laminar flow with heat transfer and the coupled hydrodynamic and electromagnetic
equations are solved using the SIMPLE algorithm. The variations in the material properties, temperature,
and velocity due to the generated arc are studied. A comparison of the results obtained with those
from the studies available in the literature validates the computational data. Since each designed plasma arc
tunnel is unique in itself and specific in application, this would enable one to alter arc discharge parameters
to optimize a specific laser.
Keywords: HF/DF, arc plasma generator, COMSOL.

HYDROGASDYNAMICS IN TECHNOLOGICAL PROCESSES
MODELING OF REFLECTION OF DETONATION
AND SHOCK WAVES FROM A RIGID WALL
IN MIXTURES OF A REACTIVE GAS
AND CHEMICALLY INERT PARTICLES
A. V. Fedorov,a P. A. Fomin,b
D. A. Tropin,a and J.-R. Chenc
UDC 534.222
An algorithm of approximate calculation of the reflection of detonation waves in mixtures of a reactive gas
and chemically inert microparticles has been proposed. Consideration has been given to the case where the
gas behind the wave front is in chemical equilibrium (D → D reflection). It has been shown that the presence
of the condensed phase can substantially decrease the parameters of the reflected wave (its velocity, pressure,
and temperature). Within the framework of a one-dimensional nonstationary approach and with allowance for
the detailed kinetics of chemical reactions, the evolution of the shock wave in a stoichiometric hydrogen-oxygen
mixture with sand particles in its reflection from a rigid wall has been calculated. The limiting particle
concentration below which the reflected wave is of the detonation type and above which it is of the shock
type has been found.
Keywords: suppression of gaseous detonation, gas-particles mixture, explosion safety.

CONDUCTION–CONVECTION–RADIATION EFFECTS
ON THE FLOW OF OPTICALLY DENSE GRAY FLUID
OVER A HORIZONTAL CIRCULAR DISK
S. Siddiqaa and M. A. Hossainb UDC 536.25
A natural convection boundary-layer flow of an optically dense gray viscous fluid (liquid metal) above a horizontal
circular disk with regard to thermal radiation is discussed. The radiative heat flux term is expressed
by using the optically thick radiation limit. The corresponding boundary-layer equations are solved with the
aid of three distinct numerical techniques: the straightforward finite difference (SFD) method is employed to
solve the problem directly, and then the stream function formulation (SFF) and primitive variable formulation
(PVF) methods based on solving transformed equations are used. The numerical results are interpreted in
terms of the local skin friction coefficient and the local Nusselt number. The influence of the problem parameters
on these characteristics is shown.
Keywords: natural convection, thermal radiation, horizontal circular disk.

LOCAL THEORY OF PARALLEL APPROACH
OF PLATES IN AN INCOMPRESSIBLE LIQUID
S. K. Betyaev UDC 532.526.2
A flow of an incompressible liquid in a thin layer between two approaching disks or plates located in parallel,
at the final stage of their symmetrical approach, is considered. It is assumed that the velocity of the body
is assigned as a function of time. An inspection analysis of the problem has been made: the types of flows
depending on the law of approaching plates and the conditions under which the pressure in the layer and,
consequently, the acting forces increase infinitely have been determined. Approximate solutions in the plane
and axisymmetric cases are suggested. Exact solutions have been obtained for infinitely small and infinitely
high Reynolds numbers.
Keywords: incompressible liquid, law of approaching plates, viscous flow regime, highly viscous flow regime,
inviscid flow regime.

STERNBERG–KOITER PARADOX IN
PROBLEMS ON INVISCID FLOW OF FLUID
S. K. Betyaev UDC 532.526.5
The problem on inviscid flow of fluid inside a wedge when the Sternberg–Koiter paradox takes place has
been considered. The flow is divided into potential and vortex and stationary and nonstationary ones. A resolution
of the paradox is given.
Keywords: singularity, bifurcation, self-similarity, superposition.

MISCELLANEOUS
THERMAL AND NEUTRON-PHYSICAL FEATURES
OF THE NUCLEAR REACTOR FOR A POWER
PULSATION PLANT FOR SPACE APPLICATIONS
E ′
. G. Gordeev,a A. S. Kaminskii,a G. V. Konyukhov,b
V. A. Pavshuk,b and T. A. Turbinaa
UDC 621.039.5
We have explored the possibility of creating small-size reactors with a high power output with the provision
of thermal stability and nuclear safety under standard operating conditions and in emergency situations. The
neutron-physical features of such a reactor have been considered and variants of its designs preserving the
main principles and approaches of nuclear rocket engine technology are presented.
Keywords: nuclear power plant, nuclear rocket engine, modular design, energy production, thermal stability,
nuclear safety, reactivity effects, burnable neutron poison, fission density.