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.