ON THE PROPERTIES OF A STEEL MODIFIED
WITH CARBON NANOMATERIALS
S. A. Zhdanok,a A. I. Sviridenok,b M. I. Ignatovskii,b
A. V. Krauklis,a T. A. Kuznetsova,a S. A. Chizhik,a
and K. O. Borisevich
UDC 536.42
Results of investigation of the surface of a steel modified with carbon nanomaterials having different contents
of carbon nanostructures by the method of atomic-force microscopy are presented. Experiments on the microhardness
of this steel have been carried out and the thickness of its modified layer was determined.
Keywords: carbon nanomaterials, nanotubes, nanofibres, steel, thermal treatment, atomic-force microscopy, microhardness.
OBTAINING CARBON NANOMATERIALS IN A PLANT
WITH A PLASMA GENERATOR AND A WORKING ZONE
OF RECTANGULAR CROSS SECTION
S. A. Zhdanok, I. F. Buyakov, A. V. Krauklis,
A. N. Laktyushin, K. O. Borisevich, and M. V. Kiyashko
UDC 536.46
Results of experimental investigations of the conditions of formation of carbon nanostructures in a plasmachemical
reactor of rectangular cross-section from the products of decomposition of hydrocarbons in a
low-temperature plasma are presented. The influence of the additional flow region on the process was determined.
Data on the content of structurized carbon in the material obtained and on the yield of the
process are presented.
Keywords: carbon nanomaterials, nanotubes, nanofibres, decomposition of hydrocarbons, plasma, electric discharge,
plasma generator.
EFFECTIVENESS OF BROWNIAN DEPOSITION
OF NANOPARTICLES FROM A GAS FLOW
IN A TUBE
S. P. Fisenko UDC 537.291:533.723
A comparison of experimental data, analytical results, and numerical calculations of the Brownian deposition
of spherical nanoparticles is carried out. It is shown that for nanoparticles smaller than 10 nm and larger
than 5 nm the relative discrepancy between experimental data and analytical results does not exceed 15%. In
other radius ranges of nanoparticles the discrepancy is substantially smaller.
Keywords: characteristic length of deposition, Brownian diffusion coefficient, tunneling probability.
HEAT CONDUCTION AND HEAT EXCHANGE IN TECHNOLOGICAL PROCESSES
INFLUENCE OF THE PREHEATING OF A WORKING
MEDIUM ON THE THERMODYNAMIC EFFICIENCY
OF PULSE-DETONATION-ENGINE PROPULSION MODULES
Yu. N. Nechaev UDC 629.7
A theoretical substantiation of calculation of the thermodynamic cycle of engines with detonation fuel combustion,
which is realized in propulsion modules of pulse detonation engines, has been given. A system of equations
for calculation of the parameters of detonation combustion waves under different conditions of their
excitation has been obtained. On their basis, investigations of the influence of different factors on the parameters
of detonation combustion waves and accordingly on the cycle work, thermal efficiency, and specific parameters
of pulse detonation engines have been performed. It has been established that the loss due to the
irreversibility of the process of heat supply in detonation combustion waves is much lower when propulsion
modules are installed in the heated-gas flow. It has been shown that the temperature of the working medium
fed to propulsion modules is the determining factor influencing the thermodynamic efficiency of the detonation-
fuel-combustion cycle. Generalized characteristics in the form of one-parameter dependences of the specific
parameters of propulsion modules of pulse detonation engines on the temperature of the working medium
fed to them have been obtained.
Keywords: detonation, deflagration, heat of combustion, entropy, irreversibility, detonation combustion, pulse
engine.
MATHEMATICAL MODELING OF THERMAL OPERATING
REGIMES OF ELECTRIC RESISTANCE FURNACES
P. S. Grinchuk UDC 536.33
A physicomathematical model making it possible to calculate thermal regimes of electric resistance furnaces
has been proposed. The model is suitable for description of linings and heated products of different types. It
includes, as components, the following models: those of thermal-radiation transfer in the furnace’s workspace,
of nonstationary heating of target products, of nonstationary heating of the furnace lining, and of external
heat exchange of the furnace’s enclosing structures. The distinctive features of a numerical method for solution
of the proposed model are discussed. An example of calculation of a chamber electric resistance furnace
for the cases where it is lined with fireclay brick and lightweight fibrous materials is discussed. It is shown
that replacement of the lining by a fibrous one improves the thermal operating efficiency for this type of furnace
2–2.5 times.
Keywords: electric resistance furnace, thermal regime, mathematical modeling.
ACCOUNT FOR HEAT TRANSFER BETWEEN
ELEMENTS OF A PLANE PARALLEL
STRIP–FOUNDATION FRICTION UNIT
A. Evtushenko and M. Kutsei UDC 536.12:621.891.539.3
An analytical solution of the boundary-value heat conduction problem for a tribosystem consisting of a semiinfinite
foundation and a plane-parallel strip sliding at a constant velocity along the foundation surface is obtained.
The thermal contact between the strip and the foundation is partial. The asymptotics of the solution
for low and high values of time have been found. For the materials of the friction pair "metal ceramics strip–
pig iron foundation" the influence of the coefficient of thermal conductivity of the contact on temperature distribution
was studied.
Keywords: temperature, heat transfer, thermal conductivity of the contact, thermal problem of friction.
FRACTURE CRITERION AND DURABILITY OF BRITTLE
MATERIALS UNDER CONDITIONS OF STATIONARY
HEAT AND MASS TRANSFER
V. V. Shevelev UDC 539.3
The equation determining the stochastic character of the development of brittle fracture of a loaded material
as a result of the extension of a fracture crack in it in the presence of stationary heat and mass transfer has
been obtained. It is shown that the evolution of the fracture crack is determined by the increment of the thermodynamic
potential of the material with a change in its characteristic dimension (length). Based on the indicated
equation, an estimate of the average durability of a loaded material with an internal rectilinear crack
under the conditions of stationary heat and mass transfer is made. From the condition of the stationarity of
the potential the brittle fracture criterion of the material and the possibility of closing the fracture crack have
been established.
Keywords: brittleness, destruction, crack, stochasticity, heat and mass transfer, stationarity, durability.
INTEGRO-DIFFERENTIAL METHOD
OF SOLVING THE INVERSE COEFFICIENT
HEAT CONDUCTION PROBLEM
V. L. Baranov, A. A. Zasyad’ko,
and G. A. Frolov
UDC 536.2.083
On the basis of differential transformations, a stable integro-differential method of solving the inverse heat
conduction problem is suggested. The method has been tested on the example of determining the thermal diffusivity
on quasi-stationary fusion and heating of a quartz glazed ceramics specimen.
Keywords: inverse heat conduction problem, differential transformations, thermophysical characteristics, thermoprotective
material, analytical model.
PHYSICAL AND MATHEMATICAL MODELING
OF ACOUSTO-CONVECTIVE DRYING OF RICE
A. V. Fedorov,a I. A. Fedorchenko,a S. B. An,b
J. H. Lee,b and K. M. Chooc
UDC 532.72;669.015.23
The present paper considers calculated and experimental data on acousto-convective drying of unhusked rice
and analyzes the data on the drying of rise in three drying cells: in two installations of the Institute of Theoretical
and Applied Mechanics (ITAM) of the Siberian Branch of the RAS — drying cells of small and medium
cross-section — and in the large cross-section installation developed jointly by the Korea Polytechnic
University and Doosan Co. LD. on the basis of the acousto-convective technology developed at the ITAM of
the Siberian Branch of the RAS. In particular, calculated velocity distributions over the cell cross-section in
the installation with a large cross-section are presented. The experiment has shown that the use of the twomode
acoustic signal for drying rice does not influence drying results as compared to the one-mode regime.
The drying rate of rice placed in the audio-frequency generator chamber differed from the drying rate in the
drying cell. The calculation method has been verified by the amplitude-frequency characteristics of the Hartmann
generator.
Keywords: acoustic drying of materials.
A METHOD FOR MEASURING THE SPECIFIC
HEAT CAPACITY OF LAYERED STRUCTURES USING
THE BOUBAKER POLYNOMIALS EXPANSION SCHEME
K. Boubaker UDC 536.2.083
An original method is used to measure the specific heat capacity of some layered structures. The conjoint
theoretical–experimental measurement protocol is based on photothermal data and polynomial expansion
mathematical analysis. The obtained value of the specific heat capacity for a solar cell buffer material is
compared to recently reported results.
Keywords: Specific heat capacity, ZnIn2S4, condensed matter, photothermal techniques.
EFFECT OF HIGHLY CONCENTRATED ENERGY FLUXES ON MATERIALS
FORMATION OF THE CONDENSED PHASE OF METALS
EXPOSED TO SUBMICROSECOND LASER PULSES
V. K. Goncharov and K. V. Kozadaev UDC 621.373.826.004.14
Using the method of laser probing, the laws governing the formation of the liquid-droplet phase of a number
of metals (Ni, Zn, Pb, Ag, and Cu) on exposure of metal targets to intense submicrosecond pulses have been
determined. It has been established that condensation from the vapor of the erosive laser jet is the main
mechanism of formation of the liquid-droplet phase of a metal under given conditions.
Keywords: erosive laser jet, submicrosecond radiation pulses, laser probing, condensed phase of metals.
CHARACTERISTICS OF EROSION PLASMA IN THE REGION
OF INTERACTION OF A FLOW WITH AN OBSTACLE
P. P. Khramtsov, O. G. Penyazkov,
V. M. Grishchenko, and I. A. Shikh
UDC 533.9.082.5; 537.523.2
Results of investigation of the characteristics of an erosion plasma flow directed to an obstacle are presented.
Stable quasi-stationary spherical plasma formations existing for more than 50 μsec were obtained for the first
time. It is shown that the parameters, length, and localization of the cumulative zone in this plasma can be
controlled by changing the dynamic characteristics of the incident flow.
Keywords: cumulative zone, plasma, erosion-plasma accelerator.
HYDROGASDYNAMICS IN TECHNOLOGICAL PROCESSES
SPIRAL VORTICES IN A CREEPING FLOW
S. K. Betyaev UDC 532.526.2
Using particular solutions of the Stokes equations as an example, it is shown that there exists a spiral vortex
in a creeping flow. The solutions are obtained with the aid of a local theory making it possible to lower the
dimensionality of the problem to unity as a result of employing a spiral coordinate and coordinate expansion
in the vicinity of the singularity, with the axial coordinate "being frozen," i.e., entering into the equation as
a parameter. The singularities of the type of focus and of limiting cycle are considered.
Keywords: focus, limiting cycle, Stokes equation, monopole, columnar vortex, conical vortex.
INTERFERENCE AND DIFFRACTION OF PRESSURE
SHOCKS IN FLOW AROUND BODIES OF REVOLUTION
LOCATED NEAR A SURFACE
V. F. Volkov, E. K. Derunov,
and A. I. Maksimov
UDC 519.85+533.696.5
This paper presents the results of experimental and computational investigations of a supersonic (M∞ = 4.03,
Re1 = 55⋅106 m−1) flow around two bodies of revolution with conical noses with an opening θ = 40o and
cylindrical cases with an extension λ = 5 located near a flat surface at zero angles of attack at a relative
distance from each other Z = 1.4. We have made a comparison between the structure of the shock waves
formed in the zone of hydrodynamic interference of the bodies of revolution in free flight and in flight over
the surface at a distance Y = 0.96. We have demonstrated the possibility of satisfactory prediction of the hydrodynamic
structure of the realized flows and aerodynamic characteristics of the bodies under investigation
on the basis of the numerical solution of Euler equations.
Keywords: aerodynamic interference, experiment, body of revolution, plate, pressure shock, diffraction, pressure
coefficient, Euler equations, wave structure.
RADIATION AMPLIFICATION OF THE METEOTRON EFFECT
L. Kh. Ingel’ UDC 551.509.6+551.558.1+532.522+536.6.011.7+536.25
The dynamics of an intense rising convective jet in the atmosphere has been investigated numerically and
analytically. Primary consideration has been given to the interaction of the jet with stably stratified "retarding
layers." The possible influence of radiation effects — heat release associated with the absorption of the shortwave
solar radiation by the carbon black contained in the jet — on the jet dynamics has been considered.
The above black is generated by the fuel combustion in the "meteotron," and can also be introduced additionally
into the jet to intensify it. It has been shown that the radiation effects can, in principle, contribute greatly
to the jet rise.
Keywords: convective jets, atmosphere, meteotron, retarding layers, radiation effects, volume heat release.
EFFECTS OF CHEMICAL REACTION ON FREE
CONVECTION FLOW THROUGH A POROUS MEDIUM
BOUNDED BY A VERTICAL SURFACE
N. Mahapatraa, G. C. Dashb,
S. Pandac, and M. Acharyad
UDK 536.25
The effect of a chemical reaction on a free convection flow through a porous medium bounded by a vertical
infinite surface has been studied. Velocity, temperature, and concentration profiles have been obtained for
different values of parameters like the Grashof number, Prandtl number, and the chemical reaction parameter
in the presence of homogeneous chemical reaction of first order. It is observed that the velocity and concentration
increase during a generative reaction and decrease in a destructive reaction. The same is true for the
behavior of the fluid temperature. The presence of the porous media diminishes the temperature.
Keywords: Chemical reaction, porous medium, generative reaction, Eckert number.
DETERMINATION OF THE OPTIMUM FREQUENCY
OF GAS VELOCITY FLUCTUATIONS IN MOTION
AND HEAT EXCHANGE OF PARTICLES
P. V. Akulich UDC 677.017.632
In a low-frequency region an analytical expression has been obtained for the optimal frequency of gas-velocity
fluctuations at which a maximum intensity of heat exchange between a gas and particles is attained. A
comparison between the values of the frequency of gas velocity fluctuations obtained from the proposed expression
with the results of numerical simulation for various diameters of particles is given.
Keywords: dynamics of particles, heat exchange, oscillations of particles and gas.
ONE-VELOCITY MODEL OF A MULTICOMPONENT
HEAT-CONDUCTING MEDIUM
V. S. Surov UDC 532.529.5
A model of a one-velocity heat-conducting heterogeneous medium with the Fourier relaxation law of heat
transfer has been constructed. It is shown that the model’s equations are of hyperbolic type. The results of
numerical experiments for a three-component mixture of ideal gases carried out with the use of the Courant–
Isaacson–Rees scheme are presented.
Keywords: one-velocity multicomponent heat conducting medium, Fourier heat transfer relaxation law, hyperbolic
systems of nondivergent form, numerical simulation.
EFFECT OF ELASTIC BOUNDARIES
IN HYDROSTATIC PROBLEMS
A. N. Volobuev and A. P. Tolstonogov UDC 532.5.52
The possibility and conditions of use of the Bernoulli equation for description of an elastic pipeline were considered.
It is shown that this equation is identical in form to the Bernoulli equation used for description of a
rigid pipeline. It has been established that the static pressure entering into the Bernoulli equation is not identical
to the pressure entering into the impulse-momentum equation. The hydrostatic problem on the pressure
distribution over the height of a beaker with a rigid bottom and elastic walls, filled with a liquid, was solved.
Keywords: impulse-momentum equation, Bernoulli equation, elastic pipeline, beaker with elastic walls.
CHARACTERISTIC FEATURES OF CALCULATIONS
OF HYDROGEN GENERATORS
V. B. Troshen’kin UDC 661.961.1
Among the methods of hydrogen generation that are economically sound for autonomous customers is the
silikol method. The technique of calculation of the cylinder gas generator circuit is given. The restrictions imposed
on the flow velocity in a three-phase reacting system are considered. It is established that the reaction
rate in the circuit as a dissipative structure is in direct correlation with the change in the Gibbs energy.
Keywords: hydrogen, technique of gas generator calculation, Gibbs energy.
HEAT TRANSFER IN COMBUSTION PROCESSES
INFLUENCE OF THE ELECTRIC FIELD ON THE SOOT
FORMATION IN THE FLAME AT A LOW PRESSURE
N. G. Prikhod’ko UDC 661.666.14
We have investigated the influence of an electric field in the form of a gas discharge on the flame pattern,
the radiographic parameters of soot particles, and the yield of fullerenes and polycyclic aromatic hydrocarbons.
It has been shown that an external electric field permits controlling the processes proceeding in the
flame, as well as the soot formation, and even increasing the soot yield under certain conditions. It has been
established that the height of the soot packet Lc and the interplanar spacing d002 remain unchanged with increasing
voltage, which is confirmed by the absence of graphitization under the action of the electric field. It
has been revealed that negative polarity has a stronger effect on the increase in the yield of fullerenes with
increasing voltage applied compared to positive polarity.
Keywords: flames, combustion, soot, electric field, pressure, hydrocarbon fuel, fullerenes.
STEAM THERMOLYSIS OF TIRE SHREDS:
MODERNIZATION IN AFTERBURNING
OF ACCOMPANYING GAS WITH WASTE STEAM
V. A. Kalitko UDC 536.246.2
On the basis of experience in the commercial operation of tire-shred steam thermolysis in EnresTec Inc. (Taiwan)
producing high-grade commercial carbon, liquid pyrolysis fuel, and accompanying fuel gas by this
method, we have proposed a number of engineering solutions and calculated-analytical substantiations for
modernization and intensification of the process by afterburning the accompanying gas with waste steam condensable
in the scrubber of water gas cleaning of afterburning products. The condensate is completely freed
of the organic pyrolysis impurities and the necessity of separating it from the liquid fuel, as is the case with
the active process, is excluded.
Keywords: shreds, tire processing, pyrolysis, fuel, carbon, gas, steam, modernization.
MISCELLANEOUS
TRANSFER PROPERTIES OF MIXTURES OF RAREFIED
NEUTRAL GASES. HYDROGEN–ARGON SYSTEM
A. G. Shashkov,a A. F. Zolotukhina,a
L. P. Fokin,b and A. N. Kalashnikovb
UDC 546.212+533.16
A method is proposed for generalization of the transport properties of mixtures of rarefied gases on the basis
of their particle-interaction potentials and relations of the molecular-kinetic theory. A simultaneous processing
of data on the viscosity of a binary Ar–H2 mixture and its components as well as data on the concentrationdiffusion
and thermal-diffusion coefficients of this mixture has been carried out by the weight method. The parameters
of three functions of the Lennard-Jones (m–6) potential of interaction between the Ar atoms and
H2 molecules in the indicated mixture were determined. Tables of reference data on the transport properties
of the Ar–H2 mixture at a temperature of 200–2000 K and a concentration x(Ar) varying from 0 to 1 were
calculated.
Keywords: gases, gas mixtures, transport properties, hydrogen, argon, viscosity, diffusion coefficient, thermaldiffusion
coefficient, interaction potential, reference data.
PHYSICAL PREREQUISITES, MECHANISMS,
AND KINETICS OF FORMATION OF Pd2
+ MOLECULAR
COMPLEXES IN METALLIC PALLADIUM
N. V. Piskunov, Yu. T. Sinyapkin,
N. A. Protopopov,∗ and V. M. Kul’gavchuk∗
UDC 541.183.1
The issue of whether Pd2
+ molecular complexes can be formed in metallic palladium has been considered. It
has been shown that in the structure of the face-centered cubic palladium crystal lattice, there are the energy
and geometric prerequisites for the formation, from the atoms at the centers of adjacent lattice faces, of
Pd2
+ molecular complexes with a hole in the 4d shell of one atom. The average content of these complexes
and holes per palladium atom has been evaluated. Possible mechanism and kinetics of formation of Pd2
+ molecular
complexes in metallic palladium have been considered.
Keywords: atom, hydrogen degradation, heterogeneous catalysis, face-centered cubic, crystal lattice, kinetics,
metallic palladium, mechanism, palladium molecular complex, shielded hydrogen complex.
A PHOTOACOUSTIC AND ULTRASONIC
STUDY ON JATROPHA OIL
G. Krishna Bamaa and K. Ramachandranb UDC 536.2
Using the photoacoustic technique, the thermal diffusivity of a dimethoxymethane + jatropha liquid mixture
and pure jatropha oil is measured at room temperature. The result is correlated with the result of ultrasonic
measurements.
Keywords: Photoacoustics, thermal properties, jatropha oil.