HEAT CONDUCTION IN TECHNOLOGICAL PROCESSES
PROPAGATION OF HEAT IN THE SPACE AROUND
A CYLINDRICAL SURFACE AS A NON-MARKOVIAN
RANDOM PROCESS
A. N. Morozov and A. V. Skripkin UDC 519.2;536.2
Consideration has been given to the propagation of heat in the space around a cylindrically shaped body in
the presence of fluctuations of the heat flux through its surface. It has been shown that the corresponding
random changes in the temperature and the heat flux are described by integral stochastic equations and belong
to the class of non-Markovian processes. Statistical characteristics of the considered fluctuations, including
one-dimensional and multidimensional characteristic functions, spectral densities, and probability densities,
have been found.
Keywords: heat conduction, non-Markovian process, integral stochastic equations.
EXACT AND APPROXIMATE SOLUTION OF ONE MIXED
PROBLEM OF THE THEORY OF HEAT CONDUCTION
WITH THE HELP OF SPECIAL FUNCTIONS
P. G. Lasyi and I. N. Meleshko UDC 536.2:519.6
A special psi function has been introduced and with its help an exact and an approximate analytic representations
of the solution of the mixed problem of the heat conduction theory for a rod have been obtained.
The advantage of the approximate formula is its relative simplicity and the absence of quadratures. An efficient
estimate of the approximate solution error has been found.
Keywords: heat conductivity, mixed problem, approximate solution, psi function.
THERMAL PARAMETERS OF CENTRIFUGAL
INDUCTION DEPOSITION OF POWDER COATINGS
I. A. Sosnovskii and Yu. N. Gafo UDC 621.793
An engineering method of calculation of the thermal parameters of centrifugal induction sintering of a powder
onto the surface of a workpiece with allowance for the geometric, thermophysical, and electrophysical parameters
of the workpiece and the powder layer and for the convective and radiative heating of the exterior
surface of the workpiece has been developed. A system for control of the temperature of the workpiece in the
process of centrifugal induction sintering of the powder coating onto it has been developed.
Keywords: centrifugal induction sintering, powder coatings, thermal parameters, stationary heat-conduction
problem, control and regulation of technological regimes.
CALCULATION OF TEMPERATURE DISTRIBUTION
AND THERMO-OPTICAL EFFECTS IN DOUBLE-END-PUMPED
SLAB LASER
P. Elahi and S. Morshedi UDC 536.24
The temperature distribution and thermo-optical effects in a double-end-pumped slab laser are investigated
analytically. The theoretical model is given by considering heat generation on both sides of an active medium
due to pumping. With account for the pump beam divergence and the heat load, the heat conduction equation
is solved, and the temperature distribution and thermal effects, such as thermal lensing and thermal stress,
are obtained. The results are applied to a typical Nd:YVO4 laser crystal slab and discussed.
Keywords: slab lasers, double-end-pumping, thermo-optical effects.
HEAT AND MASS TRANSFER IN POROUS AND DISPERSE MEDIA
COMPUTER STUDY OF THE EFFECTS
OF OZONE ABSORPTION BY AN ULTRADISPERSE
AQUEOUS MEDIUM
A. E. Galashev and O. R. Rakhmanova UDC 541.182.4:535.34
The interaction of ozone molecules with water clusters at a temperature corresponding to the middle zones of
the troposphere and the stratosphere has been studied by the molecular-dynamics method. It has been established
that the integral intensities of the infrared absorption spectrum and the Raman spectrum of an ultradisperse
aqueous system decrease substantially in absorption of ozone by it. It has been shown that in this case
the emission power of the IR-radiation energy stored by the entire ozonized disperse aqueous medium grows.
Keywords: water clusters, ozone, molecular dynamics, infrared spectra, Raman spectra, emission-power spectra.
INFLUENCE OF CARBON NANOMATERIALS
ON THE PROPERTIES OF PAINT COATINGS
S. A. Zhdanok, A. V. Krauklis, K. O. Borisevich,
N. P. Prokopchuk, A. V. Nikolaichik, and P. G. Stanovoi
UDC 536.46, 667.629
The conditions for obtaining carbon nanomaterials with the use of a low-temperature plasma are described.
The product obtained was analyzed using the electron microscopy and a laser diffraction particle-size analyzer.
The influence of the carbon nanomaterials on the physicochemical properties of paint coatings, their
adhesion, impact and bending strengths, hardness, and protection characteristics was investigated.
Keywords: carbon nanomaterials, nanotubes, nanofibres, electron microscopy, water-dispersible and organosoluble
paintwork materials, enamels, primers.
APPLICATION OF AN EQUIVALENT EQUATION
TO DESCRIPTION OF HEAT- AND MASS-EXCHANGE
PROCESSES DETERMINED BY DIFFERENTIAL EQUATIONS
IN THE DOMAIN WITH A MOVING BOUNDARY
A. I. Moshinskii UDC 539.2172:66.084
A mathematical model describing heat- and mass-exchange processes that are prescribed by differential equations
in the domain with a boundary moving with a constant velocity has been constructed for the "plane"
problem. Consideration has also been given to the "radial" problem in cylindrical coordinates where the
boundary of the domain moves according to the law of the square root of time. The proposed models can be
used for description of problems of desalination of soils, extraction, flushing of sediments, and other processes
in porous systems.
Keywords: two-component nature, mass exchange, porous body, flushing, extraction.
NUMERICAL VALUES OF THE REAL-NUMBER FACTORIAL
IN THE EQUATION OF ELUTION ADSORPTION DYNAMICS
A. V. Larin UDC 541.183:543.54
It is proposed to use the equation of elution adsorption dynamics in the discrete model of an equilibrium adsorption
layer with a continuous length coordinate. An algorithm for calculating the real-number factorial has
been substantiated, and it is shown that the integral obtained is identical to the gamma-function known in
mathematics. The properties of the equation proposed were analyzed.
Keywords: elution adsorption dynamics, real-number factorial, gamma function.
EVAPORATION OF SUSPENSIONS TO FORM
AN INCOMPRESSIBLE CAKE AND TO FILL
FILTER PORES WITH SOLID PARTICLES
B. Kh. Khuzhayorov UDC 532.546
Equations of filtration of suspensions to form an incompressible cake of particles on the surface of the filter
with simultaneous passage of a certain share of the particles from the cake to the filter’s pore space and next
to the region of a filtered liquid are derived from the principles of the mechanics of multiphase media. The
influence of the travel of the particles in the region of the cake and the filter on the dynamics of growth of
the cake bed is investigated. An analysis of the derived dynamic filtration equations shows that allowance for
the factors of travel and accumulation of particles in the cake and the filter causes their total filtration resistance,
in particular the resistance in the inertial component of the filtration law, to decrease.
Keywords: incompressible cake, filter, filtration, suspension, dynamic filtration equations, growth of the cake
bed.
RELATIONSHIP BETWEEN MURPHREE
AND COMPLEX MODEL MASS TRANSFER
EFFICIENCIES
V. N. Pavlechko UDC 66.048.3.069.835
Graphical comparison of the Murphree mass transfer efficiency with the efficiency of the complex model has
been made. We have proved and illustrated the expediency of using the Murphree mass transfer efficiency determination
in the vapor and the liquid phases for the parallel flow, the counterflow, and the crossflow at
phase equilibrium coefficients close to 1; at its other values it is recommended to use the efficiency of the
complex model. The impossibility of using the Murphree efficiency in a liquid for analyzing the mass transfer
in the counterflow of the phases, which in this case is equal to zero, has been proved.
Keywords: mass transfer efficiency, Murphree concept, complex model, comparison of mass transfer efficiencies,
parallel flow, counterflow, crossflow.
DETERMINATION OF THE THICKNESS OF THE
SURFACE MICROLAYER FROM WHICH AEROSOLS
ARE FORMED BY BURST OF GAS BUBBLES
AT THE LIQUID–GAS INTERFACE
V. M. Gasanov UDC 541.182./.3+532.696.24
The surface diameters of gas bubbles at the liquid–gas interface whose burst leads to the formation of aerosol
from a thin surface microlayer of thickness 1 μm and less have been determined experimentally. Precisely
the anomalous concentrations of such a microlayer are responsible for the fractionation of substances in the
process of ocean-atmosphere exchange.
Keywords: thin surface layer of seawater, gas bubbles, aerosol.
HEAT AND MASS TRANSFER IN COMBUSTION PROCESSES
CONVERSION OF METHANE TO HYDROGEN
IN A REVERSIBLE FLOW SUPERADIABATIC
INERT POROUS MEDIUM REACTOR
N. M. Alabbadi,a A. S. Al-Musa,a Yu. M. Dmitrenko,b
V. V. Martynenko,b S. I. Shabunya,b S. I. Al-Maiman,a
K. B. Al-Enazi,a and M. S. Al-Zhuhania
UDC 536.46
Using the analysis of the experimental data on partial oxidation of methane as an example, we have shown
that the chemical processes in the inert medium of a reciprocating flow reactor can be modeled with good
accuracy by the standard kinetic scheme for homogeneous processes due to the fact that the gas flow in the
region of combustion is described by two temperatures — the gas and framework temperatures. Such a modification
of the chemical model requires neither changing the recognized mechanism of homogeneous chemistry
nor correcting the volume heat transfer coefficient.
Keywords: partial oxidation, superadiabatic effect.
HYDROGEN PRODUCTION IN A REVERSIBLE
FLOW FILTRATION COMBUSTION REACTOR
Yu. M. Dmitrenko and P. A. Klevan UDC 536.46
The noncatalytic process of syngas production by means of partial oxidation of methane by air oxygen in a
reversible flow filtration combustion reactor has been investigated experimentally. We have investigated the influence
of the equivalent ratio and the specific mass flow of the fuel mixture on the composition of conversion
products and the maximum temperature in the reaction zone. The optimal conditions for the process providing
the most effective conversion of methane to syngas have been established. The concentration of hydrogen is
maximal for the equivalent ratio γ = 2.8 and the specific flow rate g = 1.8 kg ⁄ (m2⋅s).
Keywords: conversion of methane, syngas, partial oxidation reaction, superadiabatic effect, filtration combustion
wave, inert porous packed bed, reversible flow reactor.
MACROKINETIC CALCULATION OF THE IGNITION
OF A SOLID-FUEL CHARGE OF GLYCIDYL AZIDE POLYMER
IN THE MINI-ENGINE OF A MICROELECTROMECHANICAL
SYSTEM
S. I. Fut’ko,a E. M. Ermolaeva,a K. V. Dobrego,
a V. P. Bondarenko,b and L. N. Dolgiib
UDC 662.612.2, 662.311.1
The process of ignition of the solid fuel from glycidyl azide polymer in the mini-engine of a microelectromechanical
system has been considered. Macrokinetic calculations of the self-ignition temperature of the
fuel and the induction period for different heat transfer conditions have been made. On the basis of the critical
thermal flux determination, recommendations on the choice of the minimum power and size of the thermistor
in the igniter of the solid-fuel mini-engine have been formulated.
Keywords: macrokinetic modeling, solid-fuel rocket engines, mini-engine, igniter, critical thermal flux, self-ignition,
induction period, glycidyl azide polymer.
INFLUENCE OF ETHANOL ON THE OPERATING
PARAMETERS OF AN INTERNAL-COMBUSTION
ENGINE
M. S. Assad,a I. G. Kucharchuk,b O. G. Penyazkov,a
A. M. Rusetskii,b and A. D. Chornyia
UDC 536.46:533.6:621.4
Distinctive features of the operation of an internal-combustion engine burning ethanol-containing fuels have
been studied. It has been shown that the enrichment of gasoline with ethanol tends to diminish the concentrations
of CO and NO in combustion products, with the engine’s fuel efficiency being inevitably degraded due
to the lower volumetric heat of combustion of the blend. The experimentally confirmed technique of blocking
the growth in the concentration of NO in the combustion products of hydrogen-containing fuels by enrichment
of the blend with ethanol has been proposed; the optimum parameters of the three-fuel composition have been
established.
Keywords: combustion process, alcohols, combustion products, hydrogen-containing fuels, fuel emulsion.
HYDROGASDYNAMICS IN TECHNOLOGICAL PROCESSES
REORGANIZATION OF THE POISEUILLE PROFILE
IN NONISOTHERMAL FLOWS IN THE REACTOR
Yu. A. Stankevich and S. P. Fisenko UDC 536.423
The change in the temperature and velocity profile of the gas flow in a cylindrical reactor with variation in
the reactor-wall temperature has numerically been investigated. It has been shown that the use of the
Poiseuille profile in calculating the transient temperature profile of such a flow is quite justified. The appearance
of two extrema of the radial velocity of the indicated flow on its heating (cooling) has been predicted.
The maximum radial flow velocity reaches several percent of its initial average velocity.
Keywords: nanoparticles, gas flow, radial flow velocity, gas flow rate, thermal diffusivity.
APPLICATION OF THE SWEEP METHOD IN SOLVING
ONE-DIMENSIONAL EQUATIONS OF BLOOD FLOW
AND PULSE WAVE PROPAGATION IN THE ARTERIAL
VASCULAR SYSTEM
V. M. Popova and V. A. Babenkob UDC 532.542.2 + 612.133
A hydrodynamic model of blood flow in the arterial system of elastic vessels has been considered and an algorithm
for its calculation based on the numerical integration of one-dimensional nonstationary hydrodynamical
equations by the finite difference method is proposed. The given algorithm reduces the considered problem
to a system of nonlinear algebraic equations solved by the Newton iteration method. Within the framework of
this method, the linearized system of algebraic equations for the dendratic structure of vessels has been solved
with the use of the sweep method. Comparison of the results of calculations with the literature data has
shown that they agree with the blood flow characteristics observed in vivo during a cardiac cycle, as well as
with the experimental time dependences of the blood pressure and circulation rate in vessels.
Keywords: hemodynamics, blood circulation, one-dimensional model, elastic vessel, pulse wave, finite differences.
SOLUTION OF THE COUPLED THERMOMECHANICAL
PROBLEM OF HYDRODYNAMICS FOR DESIGNING
THE PROPULSION SYSTEM OF MICROSATELLITES
I. A. Miklashevich, E. A. Belogurov,
and Ya. I. Shukevich
UDC 629.7.036:621.45
This paper considers the problem of predicting the technical and operating characteristics of the propulsion
system of a microsatellite created by microelectronic technology. The coupled thermomechanical problem of
hydrodynamics has been solved by the ANSYS CFX package. The microengine design has been optimized, the
heating of its case in the operating time of the fuel chamber has been analyzed, and the velocity field distribution
in the microengine nozzle has been determined. The values of the mechanical and temperature deformation
fields for pure silicon and a silicon–SiO2 composite have been found, and the possibility in principle
of operation of the considered device has been shown. The calculation was made on a triangular net.
Keywords: numerical calculation, gas flow, microengine, jet nozzle.
SHADOW METHOD FOR MEASURING THE ELECTRON
DENSITY IN A BARRIER DISCHARGE PLASMA
ON THE ZHUKOVSKII AIRFOIL SURFACE
P. P. Khramtsov, O. G. Penyazkov, M. Yu. Chernik,
V. M. Grishchenko, I. N. Shatan, and I. A. Shikh
UDC 533.9.082.5;537.523.2
We have measured the electron temperature and density distributions in an ionized gas flow initiated by a
high-frequency barrier discharge on the Zhukovskii airfoil surface by the method of photometry of shadow
patterns for two probe radiation wavelength λ
r = 0.675 μm and λb = 0.425 μm. The investigation was carried
out in air at atmospheric pressure. The maximum value of the electron density was Ne 2.2⋅1015 cm−3
with an insignificant change in the air temperature in the discharge gap.
Keywords: shadow method, barrier discharge, plasma, Zhukovskii airfoil.
INFLUENCE OF THE BARRIER DISCHARGE
ON THE AERODYNAMIC DRAG OF THE ZHUKOVSKII
AIRFOIL UNDER VARIOUS AIR FLOW CONDITIONS
P. P. Khramtsov, O. G. Penyazkov, V. M. Grishchenko,
M. Yu. Chernik, I. N. Shatan, and I. A. Shikh
UDC 533.9.082.5;537.523.2
The influence of the dielectric barrier discharge plasma on the total aerodynamic drag of the Zhukovskii airfoil
has been investigated. With the use of the Pitot–Prandtl tube the velocity distribution of discharge-induced
ion wind at a distance of 18 mm from the trailing edge of the airfoil has been measured
experimentally. It has been shown that the influence of the discharge leads to a decrease in the aerodynamic
drag by a value from 10 to 34% depending on the incident flow parameters and the operating conditions of
the discharge system.
Keywords: aerodynamic drag, plasma actuator, barrier discharge, plasma, Zhukovskii airfoil.
PROPAGATION DYNAMICS OF A LIQUID
INJECTED INTO AN AQUIFER
B. I. Basok and T. A. Rezakova UDC 532.5; 536.24
With the aid of the Phoenics program package the filtration processes in the underground permeable collector
upon injection of a liquid into it have been considered. The time dependences of the injected liquid velocity
for a real gas-saturated aquifer have been obtained. The indices of using a geothermal cogenerating plant operating
on gas-saturated thermal water have been estimated.
Keywords: porous medium, filtration, underground collector, permeability, Darcy law.
A STUDY OF INDUCED MAGNETIC FIELD
WITH CHEMICALLY REACTING AND RADIATING
FLUID PAST A VERTICAL PERMEABLE PLATE
S. Ahmed UDC 504.32
The influence of thermal radiation and chemical reaction on the steady MHD heat and mass transfer by a
mixed convective flow of a viscous, incompressible, electrically conducting Newtonian fluid (an optically thin
gray gas) past a vertical permeable plate was investigated with account for the induced magnetic field. The
similarity solutions of the transformed nondimensional governing equations are obtained by the series solution
technique. The influence of numerous parameters on the process characteristics is studied.
Keywords: electrically conducting fluid, chemical reaction, radiating fluid, series solution technique, current
density, magnetic Prandtl number.
RADIATION AND THERMAL DIFFUSION EFFECTS
ON AN UNSTEADY MHD FREE CONVECTION
MASS-TRANSFER FLOW PAST AN INFINITE
VERTICAL POROUS PLATE WITH THE HALL
CURRENT AND A HEAT SOURCE
B. Prabhakar Reddya and J. Anand Raob UDC 536.25
An analysis is performed to study the effects of radiation and thermal diffusion on an unsteady MHD free
convection heat- and mass-transfer flow of an incompressible, electrically conducting, viscous fluid past an infinite
vertical porous plate with the Hall current and a heat source. The flow is considered under the influence
of a constant suction velocity and a uniform magnetic field applied normally to the flow. The
dimensionless governing equations are solved numerically by the Galerkin finite element method. The effects
of the flow parameters on the primary and secondary velocities, temperature, species concentration, shearing
stresses, Nusselt number, and Sherwood number are calculated and presented in figures and tables. The results
obtained show that a decrease in the temperature boundary layer thickness occurs when the Prandtl
number and radiation parameter are increased and an increase in the Schmidt number leads to a decrease in
the concentration boundary layer thickness.
Keywords: mass transfer, MHD, Hall current, suction velocity, heat source, Galerkin finite element method.
INVESTIGATION OF REGIMES OF THERMOGRAVITATIONAL
CONVECTION OF A FLUID BETWEEN COAXIAL
SEMICYLINDERS WITH A HEAT-CONDUCTING SHELL
IN THE PRESENCE OF A LOCAL ENERGY SOURCE
M. A. Sheremet UDC 669.86:536.21
A numerical analysis has been made of the thermodynamic regimes of natural convection of a Newtonian
fluid satisfying the Boussinesq approximation in the gap between coaxial semicylinders with finitely-thick walls
in the presence of the heat-release source under the conditions of convective heat exchange with the environment.
A mathematical model has been formulated in the dimensionless variables current function–velocity vorticity
vector–temperature in polar coordinates. Streamlines and velocity and temperature fields reflecting the
influence of the Prandtl number Pr = 0.7 and 7.0, the nonstationarity factor 0 < τ ≤ 300, the dimensions of
the energy source, and of the relative thermal conductivity on the flow regimes and heat transfer have been
obtained.
Keywords: thermogravitational convection, heat conduction, horizontal semicylinder, Boussinesq approximation,
polar coordinates.
NUMERICAL INVESTIGATION OF THE CHARACTER
OF THE LIFT ON A CYLINDRICAL PARTICLE
IN POISEUILLE FLOW OF A PLANE CHANNEL
U. Dalabaev UDC 532.529
The character of the lift on a cylindrical (porous and solid) particle in Poiseuille flow of a plane channel has
been investigated. The lift at various values of the Reynolds number, the particle size, and its position in the
flow have been calculated.
Keywords: lift, Poiseuille flow, flow around a particle.
FLOW STABILITY AND PRIGOGINE THEOREM
FOR THE STATIONARY FLOW OF A VISCOPLASTIC
BODY
V. D. Solovei UDC 539.3
A slow flow of a nonlinear viscoplastic body on whose boundary the velocities of travel are given has been
investigated for stability. We have also proved the Prigogine theory on minimum entropy production in the
case of the isothermal special stationary flow of such a body.
Keywords: slow flow of a viscoplastic body, integral estimate, special stationary flows, minimum entropy production.
NUMERICAL ANALYSIS OF THE PROCESS
OF HEATED OIL EVAPORATION FROM
THE EMERGENCY SPILL SURFACE
A. D. Galeev and S. I. Ponikorov UDC 536.2:614.83
A numerical investigation of the influence of wind velocity and spill thickness on the characteristics of heated
oil evaporation from the emergency spill surface has been made. This paper presents the results of calculating
the change with time in the mass of vapors in a cloud bounded by the concentration limits of flame
propagation.
Keywords: emergency spill, oil evaporation, numerical simulation.
THERMOPHYSICAL PROPERTIES OF SUBSTANCES
TRANSPORT PROPERTIES OF MIXTURES
OF RAREFIED GASES. HYDROGEN–METHANE
SYSTEM
L. R. Fokin,a A. N. Kalashnikov,a
and A. F. Zolotukhinab
UDC 547.211+546.11
An analysis and generalization of experimental data on transport properties based on the relations of molecular-
kinetic theory and three-parameter interaction potentials of the Lennard-Jones (m–6) family have been performed
for the mixture of rarefied neutral gases "hydrogen–methane." Nine parameters of the potentials have
been restored in joint data processing using the weight nonlinear least-squares method. Tables of reference
data for viscosity, the interdiffusion coefficient, and the thermal diffusion factor have been calculated in the
temperature interval 200–1500 K. Errors of reference data in the entire interval of concentrations, including
those of pure components, have been evaluated using the matrix of parametric errors.
Keywords: gas, gas mixtures, viscosity, interdiffusion coefficient, thermal diffusion factor, molecular-diffusion
theory, collision integrals, interaction potentials, generalization of data, hydrogen, methane.
CONTRIBUTION OF ANHARMONIC VIBRATIONS
OF STRUCTURAL ELEMENTS TO THE FORMATION
OF THERMOPHYSICAL PROPERTIES OF LINEAR
POLYMERS
B. B. Kolupaev UDC 532.546+539.199
The contribution of the higher terms of expansion of the Lennard-Jones interaction potential between structural
elements of linear polymers to the value of heat capacity and thermal conductivity of the material has
been determined. The established interrelationship of the microcharacteristics and macroproperties of the systems
makes it possible to use the procedure of calculation of Cp and λ in production and operation of polymer
materials.
Keywords: jet element, anharmonicity, linear polymers, macromolecule.
NONLINEAR COMPENSATION EFFECT
OF DYNAMIC VISCOSITY OF MULTICOMPONENT
HYDROCARBON SYSTEMS
M. Yu. Dolomatov and A. A. Ishkinin UDC 532.7+665.61+665.63
A nonlinear compensation effect determining the dependence of the energy of a flow of a Newtonian liquid on
the preexponent of its viscosity was detected. Empirical dependences relating the softening temperature of a
Newtonian high-molecular multicomponent hydrocarbon system with the activation energy of its viscous flow
have been obtained. The results obtained are supported by the statistical data and allow one to predict the
dynamic viscosity of oil and coal fractions and materials based on them.
Keywords: softening temperature, multicomponent carbon system, bitumen, tar, viscous-flow activation energy,
viscous-flow activation entropy, dynamic viscosity.