INVESTIGATION OF THE PROCESSES OF IMPREGNATION

AND DRYING OF GRANULAR SILICA GEL

A. V. Fedorov, A. A. Zhilin,

and Yu. G. Korobeinikov

UDC 532.72; 669.015.23

The process of capillary impregnation and drying of silica gel grains in the acousto-convective drier of the

ITPM of the Siberian branch of the Russian Academy of Sciences has been investigated experimentally. Two

methods for humidifying a material with developed surface and internal structures have been considered. A

comparison of these methods has been made and the influence of the impregnation rate on the geometry of

silica gel grains has been analyzed. Silica gel grains were dried by three methods: microwave, convective,

and acousto-convective. The dependence of the drying rate and the quality of the dried material on the chosen

drying method has been shown. To describe the moisture extraction, we propose a mathematical model based

on a two-dimensional diffusion equation written in the cylindrical system of coordinates. The moisture distribution

in cylindrical samples consisting of silica gel grains has been obtained numerically for various values

of the initial moisture content with the use of certain diffusion coefficients and the dependence of the moisture

transfer coefficient on the frequency of acousto-convective action.

Keywords: acousto-convective drying, granular silica gel, moisture extraction, diffusion and moisture transfer

coefficient.

MATHEMATICAL SIMULATION OF THREE-PHASE

FILTRATION IN STRATIFIED BEDS WITH ACCOUNT

FOR THE SCHEME OF JETS

V. A. Bogomolov, S. P. Plokhotnikov,

O. R. Bulgakova, and D. S. Plokhotnikov

UDC 532.546

The possibility of decreasing the dimensionality of the problem of three-phase filtration in stratified beds by

introducing modified (fictitious) phase permeabilities instead of the original relative ones that are the coefficients

of the initial system of equations within the Musket–Meres model has been investigated.

Keywords: three-phase filtration, modified phase permeabilities, stratified beds.

GENERALIZATION OF DATA ON THE PERMITTIVITY

OF THE LIQUID AND VAPOR PHASES OF WATER

FOR DETERMINING THE VAPOR CONTENT

OF TWO-PHASE STATES

Yu. V. Mulev,a K. M. Arefiev,b O. V. Belyaeva,c

M. Yu. Mulev,a and T. A. Zayatsc

UDC 621.039.534

Experimental data on the permittivity of water and steam depending on the ratio of the density to temperature

have been generalized. The relations obtained allow one to calculate the vapor content of two-phase states in

application to thermal-power plants.

Keywords: permittivity, water and steam, steam quality, two-phase state, thermal-power plants.

EXACT SELF-SIMILAR SOLUTION OF COUNTERCURRENT

CAPILLARY IMBIBITION

E. M. Lobanov UDC 532.546

Consideration is given to the one-dimensional countercurrent capillary imbibition of a wetting phase (water)

into a semiinfinite porous medium. A model based on consideration of the function of movement of self-similar

saturation profiles is proposed. An equation is derived for it, and boundary conditions are determined.

The solution of the equation gives the imbibition volume, the saturation and imbibition-flux profiles, and the

parameters at entry into the medium and on the saturation front. Calculation of the imbibition indices for a

sandstone sample is performed.

Keywords: hydrodynamic modeling, two-phase filtration, capillary phenomena, imbibition, self-similar and discontinuous

solutions of nonlinear equations, evaluation of parameters.

STRUCTURE OF A SATURATION JUMP

IN COUNTERCURRENT CAPILLARY IMBIBITION

E. M. Lobanov UDC 532.546

Consideration has been given to the structure of a saturation jump in the one-dimensional countercurrent capillary

imbibition of a wetting phase (water) into a semiinfinite porous medium. An equation having a geometric

interpretation has been derived, and boundary conditions have been determined for a stabilized zone due

to the nonequilibrium of the phase distribution. Calculation of the saturation-jump and phase-pressure profiles

has been performed for a sandstone sample.

Keywords: hydrodynamic modeling, two-phase filtration, capillary phenomena, imbibition, self-similar and discontinuous

solutions of nonlinear equations.

ON THE THERMOMECHANICS OF A HEAT-RELEASING

LAYER WITH PARTICLES OF VARIABLE SIZE

Yu. S. Teplitskii and V. I. Kovenskii UDC 532.5

The motion of a gas through a heat-releasing layer of particles of variable size is considered. A generalized

equation for calculating the resistance of the layer allowing for the compressibility of the gas has been obtained,

as well as the dependence of its dynamic viscosity on temperature. The value of the critical pressure

at the inlet to the layer below which a stationary regime of heat carrier filtration does not exist is described.

Using as an example a layered furnace, the implementation of the proposed technique is demonstrated.

Keywords: granular bed, variable size of particles, heat release, gas compressibility, critical pressure.

LAWS GOVERNING THE FRAGMENTATION

OF A DROPLET IN A HIGH-SPEED STREAM

A. G. Girin UDC 532.529.6

A common solution of the equations of ablation and motion of a droplet undergoing fragmentation in a homogeneous

high-speed gas stream is obtained. Based on the approximate solution of the equation for the

quantity of torn off droplets, an expression for the droplet size distribution function corresponding to these

laws has been found. A comparison of the results of calculations carried out for the obtained distribution

function with the same calculations for the earlier found function with the use of the empirical law of droplet

motion points to their satisfactory agreement.

Keywords: fragmenting droplet, laws of motion and ablation, daughter droplets, size distribution function.

RHEOLOGICAL PROPERTIES OF HIGH-CONCENTRATION

SUSPENSIONS USED FOR OBTAINING ELECTRORHEOLOGICAL

MEDIA

S. O. Il’in,a A. Ya. Malkin,a E. V. Korobko,b

Z. A. Novikova,b and N. A. Zhuravskiib

UDC 539.3/.6:539.5

The rheological properties of high-concentration suspensions used for making electrorheological media have

been investigated. We have established the characteristic features of their behavior, including the passage

over the yield point with a decrease in viscosity by several decimal orders of magnitude and strain hardening

followed by an increase in the shear stress. The effect of thixotropy of these systems and the role of the preceding

deformation have been described. The effect of self-sustained stress oscillations resulting from the ambiguity

of the rheological characteristic of the material has been revealed.

Keywords: electrorheological media, rheological properties, straining conditions, plasticity, viscosity, solid-like

and liquid-like structures, thixotropy, self-sustained stress oscillations.

MATHEMATICAL MODELING OF THE LYSIS

OF CLOTS IN BLOOD VESSELS

E ′

. M. Khramchenkov and M. G. Khramchenkov UDC 532.546

A mathematical model of the lysis of clots in blood vessels has been constructed on the basis of convectiondiffusion

equations. The fibrin clot is considered as an immobile solid phase, and the plasminogen, plasmin,

and plasminogen activators — as dissolved liquid phases. As a result of the numerical solution of the model,

dependences predicting the development of the lysis process have been obtained. An important role of clot

swelling in the process of lysis has been revealed.

Keywords: lysis model, convection-diffusion equations, clot, fibrin, plasminogen, plasmin, plasminogen-activator.

MHD FLOW AND HEAT TRANSFER IN A CHANNEL

BOUNDED BY A SHRINKING SHEET AND A PLATE

WITH A POROUS SUBSTRATE

D. S. Chauhan and R. Agrawal UDC 536.25+537.84

This research is concerned with heat transfer and an MHD flow of a viscous incompressible electrically conducting

fluid in a channel bounded by a shrinking sheet and an impermeable plate. A fluid-saturated porous

substrate of a very low permeability is attached to the impermeable plate. The flow in the channel is induced

by the upper shrinking sheet, where a constant suction is imposed. By introducing the similarity transformations,

the governing partial differential equations for the flow and heat transfer are transformed to ordinary

differential equations which are solved analytically by using the perturbation series method for a small

shrinking parameter. Expressions for the velocity distribution, temperature field, skin friction, and heat transfer

rate are obtained, and numerical computations are carried out for various parameters. The results are

displayed graphically and discussed.

Keywords: MHD flow, heat transfer, shrinking sheet, porous substrate, permeability.

HEAT AND MASS TRANSFER AT CHEMICAL TRANSFORMATIONS

MATHEMATICAL MODELING OF THE INITIATION

AND SPREAD OF PEAT FIRES

A. M. Grishin and A. S. Yakimov UDC 511.534.536.245.022

We propose a new statement and a numerical solution of the problem on ignition of a peat bed as a result

of the action of the nucleation site of a low fire on the basis of the mathematical model of a porous reactive

medium. It has been obtained that at moderate temperatures (T2 ≤ 750 K) the smoldering of the original reactant

is determined by the processes of heat and mass exchange with the nucleation site of the forest fire,

drying, and pyrolysis of peat, as well as by the oxidation reaction of carbon oxide, the peat height, and the

thickness of the water stratum under its bed.

Keywords: peat, drying, pyrolysis, smoldering, water.

EXPERIMENTAL INVESTIGATION OF THE KINETICS

OF HYDROLYSIS OF SODIUM BOROHYDRIDE

AQUEOUS-ALKALINE SOLUTIONS

A. A. Nesteruk, V. I. Kalinin, V. G. Minkina,

V. V. Martynenko, and S. I. Shabunya

UDC 543.637:546.271-386

Distinctive features of an experimental procedure for determination of the conversion of sodium borohydride

in hydrolysis in an aqueous-alkaline medium are described; the procedure is based on measuring the amount

of the released hydrogen. Technical and methodological features of implementation of this procedure and

measurement errors are discussed; a technique for calculation of the conversion of sodium borohydride in hydrolysis

is presented. Experimental data in the form of the constants of a quasistationary hydrolysis regime

are given for different isothermal conditions. The range of experiments covers temperatures from 20 to 95oC

and alkali concentrations from 10–2 to 5 M.

Keywords: sodium borohydride, hydrolysis, experimental procedure, conversion, hydrolysis constant.

THERMODYNAMIC ANALYSIS OF SOLID-FUEL MIXTURES

GLYCIDYL AZIDE POLYMER (GAP)/RDX FOR MINIENGINES

OF MICROELECTROMECHANICAL SYSTEMS

S. I. Fut’ko,a E. M. Ermolaeva,a K. V. Dobrego

V. P. Bondarenko,b and L. N. Dolgiib

UDC 662.612.2,662.311.1

On the basis of thermodynamic calculations we show that solid-fuel mixtures glycidyl azide polymer/RDX are

promising for use in miniengines made on the basis of technologies of microelectromechanical systems of

semiconductor microelectronics. It has been shown that small (up to 20 mass percent) additives of RDX to the

glycidyl azide polymer markedly increase the values of the theoretical specific impulse and the thermal efficiency

of the engine and decrease the quantity of undesirable solid carbon formed in combustion products of

the mixed fuel. In so doing, these mixtures provide fairly low combustion temperatures not exceeding the

thermostability limit of crystal silicon from which the miniengine case is made. The physicochemical factors

influencing the value of the theoretical specific impulse of the mixed solid-fuel charge have been elucidated,

and methods for its maximization have been proposed.

Keywords: mixed solid fuel, combustion of rocket fuels, mathematical modeling, rocket engines on solid fuel,

technologies of microelectromechanical systems, thermodynamic, RDX, glycidyl azide polymer, specific impulse

of propulsion.

EFFICIENT REGIMES OF BUTADIENE RUBBER

SYNTHESIS ON SEPARATE SUPPLY OF FEEDSTOCK

TO CASCADE REACTORS

G. V. Manuiko, D. V. Bashkirov, G. A. Aminova,

V. V. Bronskaya, T. V. Ignashina, A. I. Ismagilova,

G. S. Diyakonov, and A. G. Sakhabutdinov

UDC 61.13.21;61.13.03;61.59

Mathematical simulation of the synthesis of butadiene rubber on the basis of a neodymium-containing catalytic

system in a cascade of continuously operating reactors is carried out. Expressions for the characteristics

of the branching of the synthesized polymer macromolecules have been derived. Efficient regimes of rubber

synthesis on separate supply of feedstock to the cascade reactors allowing one to obtain rubber with specified

parameters without losing the cascade capacity have been determined.

Keywords: butadiene rubber, molecular-weight characteristics of a polymer, cascade of reactors, mathematical

simulation.

NANOSTRUCTURES

ON FORMATION OF CARBON CLUSTERS

ON A SUBSTRATE IN PLASMA PYROLYSIS

OF HYDROCARBON GASES

D. A. Takopulo and S. P. Fisenko UDC 533.915:001.573

The influence of nanoparticles of soot precipitated onto a catalytic metal substrate from a flow on the formation

of carbon clusters in a supersaturated solid solution on the substrate boundary is considered. The free

energy and the probability of the formation of critical clusters are considered.

Keywords: critical cluster, surface tension, supersaturation of a solution, diffusion.

INVESTIGATION OF SEMICOMMERCIAL

ARC PLANTS FOR FULLERENE-PRODUCTION

N. I. Alekseev, B. M. Filippov,

I. V. Basargin, and A. I. Sedov

UDC 53.06.66.088, 54.171

Results of investigation of new-generation semicommercial arc plants for fullerene production are described.

Increase in the operating efficiency of the plants is attained through their modification, in particular, by using

a system of two-sided gas feed. Increase in the electrode diameter and rise in the working pressure make it

possible to organize fullerene synthesis with a substantially smaller carbon loss. A qualitative and calculated

interpretation of the results is given.

Keywords: fullerenes, arc fullerene synthesis.

COMPOSITE FIBERS BASED ON ORDERED CARBON

NANOTUBES AND POLYVINYL ALCOHOL

N. I. Savchina-Imbro,a S. A. Filatov,a G. S. Akhremkova,a

M. Maugey,b and P. Poulinb

UDC 539.216.1:661.6

The technique of fabrication of polymer–carbon nanotube composite fibers with different types of nanotubes is

described. An analysis of the structure of the fibers obtained is carried out. The results of measurements of

the electrical and mechanical characteristics of fibers are presented.

Keywords: carbon nanotubes, composite fibers.

TRANSFER PROCESSES IN A LOW-TEMPERATURE PLASMA

DYNAMICS OF FORMATION OF THE COMPRESSION PLASMA

FLOW IN A MINIATURE MAGNETOPLASMA COMPRESSOR

V. M. Astashinskii, A. M. Kuz’mitskii,

and A. A. Mishchuk

UDC 533.9.08

Results are presented of studying integral parameters of the developed miniature gas-discharge magnetoplasma

compressor and dynamics of formation of the compression plasma flow. Energy parameters of the discharge

in this system are determined.

Keywords: magnetoplasma compressor, compression plasma flow, modification of materials.

STUDY OF THE SPECIFIC FEATURES OF PULSED-PLASMA

GENERATION IN AIR AT ATMOSPHERIC PRESSURE

Ya. A. Chivel’,a O. O. Kuznechik,a D. V. Min’ko,a

I. S. Nikonchuk,b A. V. Chumakov,b and K. E. Belyavinc

UDC 621.373.826:621.762

The structural scheme and operational characteristics of a pulse-plasma device generating a pulsed plasma in

air at atmospheric pressure are presented. The functional scheme and the operation algorithm for a high-voltage

power supply are given. It is shown that the pulsed-plasma device can generate air plasma flows with a

frequency of 1–10 Hz and maximum parameters of pressure, temperature, and velocity of 6.5 MPa, 12,000 K,

4 km ⁄ s, and 110 dBA, respectively. Comparative analysis is presented of these quantities with characteristics

of the plasma flow generated by the detonation pulsed-plasma device, which uses an air-propane mixture as

the plasma-forming substance. It is shown that replacing the air-propane gas mixture with air provides a 70

dBA decrease in the noise level of the pulsed-plasma treatment. Recommendations are given as to using the

pulsed-plasma device for surface strengthening of the instrument and parts of the machine.

Keywords: pulsed plasma, air pulsed-plasma treatment, high-voltage power-supply unit, pulsed plasma flow,

pressure, acoustic noise, temperature.

UTILIZATION OF USELESS PESTICIDES

IN A PLASMA REACTOR

A. V. Lozhechnik, A. L. Mosse′, V. V. Savchin,

D. S. Skomorokhov, and I. V. Khvedchin

UDC 504.064.4; 658.567

Investigations on destruction of isophene C14H18O7N2 and the butyl ether of 2,4-dichlorophenoxyacetic acid

(Cl2C6H3OCH2COOCH2CH(CH3)2) are performed. The plasma treatment of toxic waste is implemented in a

plasma reactor with a three-jet mixing chamber. Air is used as the plasma-forming gas.

Keywords: pesticide treatment, plasma reactor, plasma waste treatment.

CHARACTERISTIC FEATURES OF DIAGNOSTICS

OF SUPERSONIC HIGH-TEMPERATURE

JET PARAMETERS

V. V. Chuprasov,a M. S. Tret’yak,a

and A. F. Klishinb

UDC 536.25:536.45

The distribution of the gas temperature over the radius of a supersonic high-temperature free underexpanded

jet at different distances from the plasmatron nozzle cut, as well as the distribution of the stagnation pressure,

heat flux, and shock layer thickness along the length of a supersonic high-temperature blocked jet, is investigated

experimentally depending on the sensor diameter. It is shown that in the calculation of the Mach number,

static pressure, and thermodynamic enthalpy of the air of the underexpanded jet (near the nozzle cut), it

is necessary to account for the thickness of the shock layer formed upstream of the sensor.

Keywords: supersonic high-temperature jet, temperature, stagnation pressure, heat flux, shock layer thickness.

INFLUENCE OF INLET CONDITIONS

ON VORTEX CHARACTERISTICS

A. Essiptchouk UDC 536.24

Vortex chambers are normally used for arc stabilization in linear plasma torches. In the present work, the effect

of uniformity of the gas inlet channel distribution on the stabilizing characteristics of a swirled flow is

studied numerically. The formation of a complex flow pattern with a toroidal recirculating flow area inside

the vortex chamber is observed. For some regimes, two local maxima of the tangential velocity are observed

in the middle section of the chamber. It is shown that an increment of the number of gas inlet channels leads

to a more uniform gas input with disappearance of the second maximum, which increases the velocity amplification

coefficient and, correspondingly, results in a better stabilizing effect. The obtained profiles of the radial

distribution of the tangential velocity are compared with the results of Oseen’s equation for an

unconfined vortex.

Keywords: plasma torch, vortex chamber.

HEAT TRANSFER AND THERMOPHYSICAL PROPERTIES OF MATERIALS

INVESTIGATION OF THE TEMPERATURE

FIELDS OF A GAS FLOW IN A WELL

A. I. Filippov, O. V. Akhmetova,

M. A. Zelenova, and A. G. Krupinov

UDC 550.832.6

It is shown that the problem of the temperature field of an expanding ascending gas flow in a well with account

for the dependence of density on the depth can be successfully solved on the basis of the "exact on average"

asymptotic method. An expression averaged over the cross section of the well has been found for the

temperature, as well as for its radial profile. The dependences constructed make it possible to judge the character

of the change in the temperature along the well shaft and in time and allow one to interpret the thermograms

of gas wells.

Keywords: temperature field of a fluid, gas well, "exact on average" asymptotic method, gas flow.

MATHEMATICAL SIMULATION OF THE PROCESSES

OF HEAT TRANSFER AND PHASE TRANSFORMATIONS

WITH ALLOWANCE FOR ABLATION

V. A. Kudinov and I. V. Kudinov UDC 536.2(075)

Based on the introduction of the temperature perturbation front and of additional boundary conditions, an approximate

analytical solution of the heat conduction problem with account for the displacement of the melting

front with complete removal of the melted substance (the Stefan problem with ablation) has been obtained.

The technique proposed in the work for constructing additional boundary conditions allows one to apply a

model (approximating) representation of the solution with the possibility of attaining the specified degree of

accuracy.

Keywords: temperature perturbation front, melting front, Stefan problem, integral methods, additional boundary

conditions, heat of phase transition.

DETERMINATION OF THE THERMOPHYSICAL

CHARACTERISTICS OF CERTAIN STRUCTURAL

MATERIALS UNDER THE CONDITIONS OF THERMAL

ACTION FROM A HIGH-TEMPERATURE GAS JET

A. N. Golovanov, A. Ya. Kuzin,*

V. L. Mikov, and V. V. Sazonov

UDC 536.24.014

Thermophysical characteristics of phenolic carbon-filled plastic P-5-13P and graphite V-1 have been investigated

on an experimental setup simulating an actual solid-propellant rocket engine. Temperature and heat-flux

density on the thermally stressed boundaries of samples of the materials under study have been determined by

solution, with a regularizing algorithm, of the boundary inverse problem.

Keywords: heat transfer, thermophysical characteristics, structural material, mathematical modeling.

THERMAL PROPERTIES OF THE FOREST

SOIL COVER MATERIAL AT A CHARACTERISTIC

MOISTURE CONTENT

V. R. Sobol,a P. N. Goman,b I. V. Dedyulya,a

A. G. Brovka,c and O. N. Mazurenkod

UDC 553.97

We have investigated by the methods of a given stationary heat flow and calorimetry the heat conductivity

and the heat capacity of the typical soil cover materials of a coniferous forest such as fallen-off pine needles,

moss, and lichen. Samples of the investigated materials differed in the bulk density and moisture content that

were varied over the ranges characteristic of the natural conditions of the geographic latitudes of Belarus.

The elucidated laws of the change in the thermal characteristics of the above materials were investigated with

the use of the generalized models of the heat transfer in heterophase media and self-consistent calculation of

a layered medium with percolation in the direction parallel to the thermal energy transfer.

Keywords: heat conductivity, heat capacity, temperature gradient, absolute humidity, forest soil cover material.

MISCELLANEOUS

THERMOMECHANICS OF THE JOINT–SYNOVIAL

FLUID SYSTEM UNDER PERIODIC AND IMPULSE

ACTIONS

E ′

. M. Kartashov UDC 678

The thermomechanical reaction of the joint–synovial fluid system to periodic and impulse actions has been investigated.

The behavior of the body of the joint near the articular surface — resistance of the bone material

of the joint to periodic mechanical actions — has been established. It has been shown that the most destructive

actions for the joint are instantaneous impulse shock mechanical actions.

Keywords: synovial fluid, articular surface, temperature heating, temperature stresses.

FORMATION OF NEW MATERIALS BASED

ON CAST ALUMINUM ALLOY

S. M. Usherenko,a E. I. Marukovich,b Yu. S. Usherenko,c

A. I. Belous,c and A. N. Petlitskiic

UDC 634.2

We show the dynamic formation of composite materials using the polycrystalline cast alloy Al + 12% Si as

the example. The volume fraction of the synthesized framework ("influence zones") of the composite material

has been estimated to be at a level of 11%. Upon the introduction of lead a material practically insoluble

under the experimental conditions was synthesized in the framework. Upon the introduction into the Al + 12%

Si cast alloy of silicon carbide particles, we obtained a material with a specific corrosion exceeding by a factor

of 5.6 the given index of the source matrix material.

Keywords: superdeep penetration, reinforcing framework, composite aluminum materials, corrosion resistance.

SUPERFINISHING POLISH OF DIAMOND

SUBSTRATES FOR EPITAXIAL TECHNOLOGY

G. V. Sharonov and S. A. Petrov UDC 621.3.084.866

The regimes of superfinishing vibropolish of single-crystal synthetic diamond substrates have been optimized.

It has been established that after polishing for 100 h the surface roughness was 0.43 nm. A method for controlling

the structural perfection of the near-surface layers of diamond substrates upon their grinding and polishing

has been proposed and substantiated. X-ray diffraction studies point to the possibility of using the

given method in selecting suitable substrates for the technology of growing diamond films in micro- and

nanoelectronics.

Keywords: single-crystal synthetic diamond substrate, grinding, superfinishing vibrational polish, epitaxial technology,

roughness and perfection of the crystal structure, diffraction angle of x-rays, halfwidth and asymmetry

of the reflection curve of x-rays.

WAVE PROPAGATION AT THE IMPERFECT BOUNDARY

BETWEEN TRANSVERSELY ISOTROPIC THERMODIFFUSIVE

ELASTIC LAYER AND HALF-SPACE

Rajneesh Kumar and Vijay Chawla UDC 536.21

The aim of the present investigation is to study surface wave propagation at the imperfect boundary between

two transversely isotropic thermodiffusive elastic objects: a layer of finite thickness and a half-space, in the

context of the Green–Lindsay theory. The secular equation for surface waves in a compact form is derived

after the mathematical model has been developed. The phase velocity and attenuation coefficient are obtained

for stiffness (normal and tangential), thermal conductance, and for the case of a welded contact. The dispersion

curves for these quantities are presented to depict the effect of stiffness and thermal relaxation times. The

amplitudes of displacements, temperature, and concentration at the free plane boundary, as well as the specific

loss of energy, are obtained and presented graphically. The special cases are considered and the results

are compared with the known ones.

Keywords: transversely isotropic layer, generalized thermoelastic diffusion, stiffness, phase velocity, attenuation

coefficient, amplitude.