Volume 97, №1
INVESTIGATION OF RADIATIVE-CONDUCTIVE HEAT TRANSFER BY NONCONTACT MEASUREMENTS. 3. IDENTIFICATION OF MATHEMATICAL MODELS OF HEAT TRANSFER FOR SEMITRANSPARENT MATERIALS
The authors have solved the problem of simultaneous determination of a set of coeffi cients of a mathematical heattransfer model for semitransparent materials: the thermal conductivity of a material and the coeffi cient of its heat
exchange with the external medium, the heat fl ux from the heater, that has been absorbed by the material, and the
coeffi cient of linear absorption of the material.
Author:
D. S. Semenov, A. V. Nenarokomov, S. A. Budnik, D. M. Titov
Keywords:
heat transfer, hyperthermia treatment, biological tissues, inverse heat-transfer problem, semitransparent materials
Page:
1
INTEGRAL TRANSFORM METHOD FOR SOLVING INHOMOGENEOUS HEAT EQUATION WITH MIXED BOUNDARY CONDITIONS
The inhomogeneous heat equation for a semi-infi nite cylindrical solid body with mixed boundary conditions of the
fi rst and second kinds on the surface of the cylinder was solved using the Laplace and Hankel integral transforms.
The solution of the mixed boundary-value problem was reduced to the dual integral equations which were solved
using an appropriate substitution, and their solution was fi nally reduced to the Fredholm integral equations of the
second kind which were solved by the infi nite series method
Author:
N. A. Hoshan
Keywords:
inhomogeneous heat equation, mixed boundary conditions, dual integral equations
Page:
11
RADIATION COOLING OF A NONMONODISPERSE DROPLET FLOW IN A FRAMELESS SYSTEM FOR REJECTION OF A LOW-POTENTIAL HEAT IN THE OUTER SPACE
The radiation cooling of a nonmonodisperse droplet fl ow in a droplet cooler-radiator was investigated. Diff erent
reasons for the deterioration of the monodispersion of such a fl ow were considered, and the characteristic deviations
of the sizes of the droplets in this fl ow from the standard ones under diff erent conditions were determined. The
infl uence of the monodispersion of the indicated fl ow on the overradiation of the droplets in it and on their cooling
was investigated numerically and analytically. The estimates obtained allow one to forecast the infl uence of the
nonmonodispersion of a droplet fl ow in a droplet cooler-radiator on the effi ciency of its work.
Author:
A. A. Safronov
Keywords:
droplet cooler-radiator, radiation cooling, monodisperse droplet flow
Page:
18
ANALYSIS OF THE PROCESS OF THERMOSTABILIZATION OF A HIGH-TEMPERATURE SURFACE WITH DISPERSED FLOW
Experiments have been performed to investigate the effi ciency of the process of thermostabilization of a hightemperature surface with dispersed fl ow of a heat transfer agent at a pressure of 0.2–0.6 MPa in it and at a mass rate of fl ow of heat transfer agent of (3.3–6.15)·10–3 kg/s and a surface sprinkler density of 1.67–3.11 kg/(m2
·s).
Assessments have been made of the amount of heat transfer agent evaporating in all investigated heat transfer
regimes. An equation describing various heat transfer regimes has been obtained for heat transfer from a hightemperature surface to a dispersed fl ow of a heat transfer agent in a criterial form. Criterial equations qualitatively
describe experimental data within a small error, which indicates their satisfactory reproducibility in the said range
of regime parameters of the process
Author:
V. S. Shteling, Yu. V. Vershinina, A. V. Dedov, A. V. Zakharenkov, A. T. Komov, P. P. Shcherbakov
Keywords:
dispersed fl ow, heat transfer agent, heat fl ux, cooling, hydraulic circuit, heat transfer coeffi cient, experimental investigations
Page:
26
ON FILTRATION IN SOME PROBLEMS OF UNDERGROUND HYDRODYNAMICS
Simulation of fi ltration fl ows under the Zhukovskii sheet pile through a soil mass underlain by an impermeable base
or by a highly permeable pressure aquifer was carried out using two schemes within the framework of the theory
of fl at steady-state fi ltration of an incompressible fl uid according to Darcy's law. The infl uence of evaporation or
infi ltration on the free surface of ground water was studied based on solving mixed boundary-value problems of
the theory of analytical functions using the Polubarinova-Kochina method. Algorithms have been developed for
calculating the saturated zone of soil in the case of water moving in it is determined by the backing of the soil from
its impermeable base or the underlying well-permeable aquifer, evaporation or infi ltration on the free surface of
ground water and by soil capillarity
Author:
É. N. Bereslavskii
Keywords:
fi ltration, infi ltration, evaporation, ground water, free surface, Zhukovskii sheet pile, PolubarinovaKochina method, complex velocity, conformal mapping, Fuchs class equations
Page:
33
IMPREGNATION OF COMPOSITE MATERIALS BASED ON LONG CARBON FIBERS WITH A THERMOPLASTIC BINDER WHEN PRODUCING PREPREG
The fi ltration of liquid in carbon fi bers during their impregnation is considered. A quantitative relationship has
been proposed between the mechanical compressive properties of long fl at carbon threads and their permeability
coeffi cient in the direction perpendicular to the surface of the thread. A model based on a nonstationary solution
of a one-dimensional fi ltration problem has been developed for calculating the process of impregnation of fi bers
with a thermoplastic binder. As a result of a comparative analysis of experimental and calculated data, the dynamic
viscosity of the melt and an analogue of its surface tension forces were assessed.
Author:
E. V. Slavnov, V. M. Timofeev, A. I. Sudakov
Keywords:
fi ltration, carbon fi bers, compression, impregnation, thermoplastic bond
Page:
43
DYNAMICS OF SATURATION OF A STRATUM IN THE ZONE OF PENETRATION OF A DRILLING AGENT INTO IT
A solution of the nonlinear problem on the driving of the oil from an oil-bearing stratum of fi nite length by the fi ltrate
of a drilling agent (fl ushing water) has been constructed with the use of the asymptotic method. On the basis of this
solution, the saturation fi eld of the stratum in the zone of penetration of the fl ushing water into it was investigated
with regard for the process of opening of the stratum by drilling. The indicated solution defi nes the movement, along
the thickness of the stratum, of the boundary, corresponding to the position of a drill bit, above which the saturation
of the stratum with the fi ltrate of the fl ushing water and the velocity of fi ltering of this water are prescribed, and,
below this boundary, the velocity of the water fi ltration fl ow and the stratum saturation are assumed to be equal to
zero. It is shown that, within large times, the solution obtained conforms with the known Buckley–Leverett expression.
On the basis of the computational experiments, spatial and time distributions of the stratum saturation in the zone
of penetration of the fl ushing water into it have been constructed with regard for the process of opening of the
stratum.
Author:
A. I. Filippov, M. A. Zelenova, I. F. Kabirov, T. M. Levina
Keywords:
stratum, saturation, asymptotic method, fl ushing water, drilling
Page:
51
INFLUENCE OF THE GENERATION OF GAS BUBBLES IN FLOODED LEAD–ACID BATTERIES ON THEIR THERMAL BEHAVIOR
The thermal behavior of fl ooded lead–acid batteries with diff erent distances between their electrodes, in which there
takes place a temperature rise, was investigated at diff erent rates of charging and discharging of these batteries with
the use of the PIV method. It was established that, in the case of small rates of charging and discharging of such a
battery, a decrease in the distance between its electrodes leads to a decrease in the temperature rise and in the heat
generation in it, while, in the case where these rates are large, the opposite eff ects take place
Author:
S. Nahidi, M. Salari, I. J. Gavzan, S. Saedodin
Keywords:
fl ooded lead–acid batteries, electrodes, insoluble gas bubbles, heat generation, temperature rise
Page:
63
DEVELOPMENT OF A POROUS TUNGSTEN CARBIDE COMPOSITE MATERIAL, ITS STRUCTURE, PROPERTIES, AND PATTERN OF HIGH-VELOCITY INTERACTION WITH STEEL PLATES
High-temperate vacuum sintering has been used to obtain porous composite tungsten carbide alloy TNIC
(W–Ni–Fe–Co) + 69 wt.% WC. The results of investigations into the microstructure and physical-mechanical
properties of the alloy are presented. An experimental investigation has been conducted into the high-velocity
interaction of cylindrical strikers made of this material with steel plates in the velocity range of 1200–1400 m/s.
Author:
V. V. Burkin, A. S. D′yachkovskii, A. N. Ishchenko, V. A. Kudryavtsev, A. Yu. Sammel′, A. B. Skosyrskii, E. Yu. Stepanov
Keywords:
tungsten carbide, composite alloy, physical-mechanical properties, cylindrical striker, steel plate, highvelocity interaction
Page:
78
STRATEGIES OF THE COLD START OF POLYMER ELECTROLYTE MEMBRANE FUEL CELLS
Processes proceeding in polymer electrolyte membrane fuel cells at negative temperatures were investigated.
Mechanisms of degradation of the active electrocatalytic layers and gas-diff usion electrodes of these cells in the
case of freezing of the water in them were considered. Methods of decreasing or excluding the detrimental eff ect of
negative temperatures on the characteristics of the indicated cells and engineering solutions on the provision of their
cold start have been proposed
Author:
S. A. Grigor′ev, M. A. Klimova
Keywords:
fuel element, polymer electrolyte membrane, freezing, negative temperature, cold start
Page:
82
INFLUENCE OF VARIOUS FACTORS ON THE FLOW OF A CHEMICALLY REACTIVE NON-NEWTONIAN FLUID IN A PLANE CHANNEL
A study has been made of the fl ow of a non-Newtonian polymer medium in a plane channel and of heat transfer in
it with boundary conditions of the fi rst kind for small Reynolds numbers and a large Péclet number with the Ellis
rheological model with a viscosity dependent on the temperature, pressure, and degree of chemical conversion of
the medium. Consideration was given to the fl ow of a high-viscosity medium with chemical reactions leading to an
abrupt increase in its viscosity for whose mathematical description the authors used a model that included the kinetic
chemical-reaction equation and the energy equation with a dissipative term. Signifi cant infl uence of various factors
on the formation and rate of growth of the solidifi ed wall layer in such fl ow has been shown. The problem has been
solved numerically by the fi nite-diff erence method according to the iterative scheme
Author:
A. V. Baranov
Keywords:
non-Newtonian fl uid, heat transfer, nonisothermal fl ow, dissipation
Page:
92
MATHEMATICAL SIMULATION OF TURBULENT COMBUSTION OF AIR–PROPANE MIXTURE IN SWIRL FLOW
An investigation has been made into a turbulent combustion of an air–propane mixture in a swirl fl ow. To calculate
an averaged velocity of a chemical reaction, use was made of a combination of an eddy dissipation model and a
kinetic model with account for turbulent pulsations. The infl uence of a weak swirl on fl ame localization is low. If the
length of the recirculation zone occurring in a strong fl ow vortex exceeds the length of the prefl ame zone, the fl ame
front is entraped by the recirculation zone and moves upstream towards the channel inlet where fl ame stabilization
occurs. At the initial segment of the fl ow, the chemical reaction is determined by Arrhenius kinetics. In the region
directly adjacent to the fl ame, the combustion mechanism controlled by turbulence becomes signifi cant.
Author:
O. V. Matvienko
Keywords:
turbulence, combustion, swirl fl ow, air–propane mixture, heat transfer, computational fl uid dynamics
Page:
97
ACTION OF AN ELECTRON BEAM AND AN EXTERNAL ELECTRIC FIELD ON A PROPANE–AIR MIXTURE
The infl uence of the preliminary ionization of a combustible mixture and the excitation of its molecules by an electron
beam and an external electric fi eld on the intensity of burning of this mixture at diff erent rates of its excitation was
considered. Results of calculations of the ignition temperatures of a dry mixture of propane and air as well as of their
wet mixture are presented. Recommendations for the exposure of a subsonic fl ow of such a mixture to an electron
beam in an external electric fi eld for increasing the effi ciency of burning of the mixture are given.
Author:
P. V. Bulat, K. N. Volkov, L. P. Grachev, I. I. Esakov, P. B. Lavrov, M. E. Peneva
Keywords:
plasmochemistry model, chemical reactions, plasma burning, electron beam, electric fi eld
Page:
109
PLASMA IGNITION OF SOLID FUEL: MATHEMATICAL SIMULATION AND EXPERIMENT
A thermodynamic analysis was performed using the universal TERRA program, which made it possible to determine
the optimal parameters of the process of plasma ignition and stabilization of solid fuel combustion. Kinetic modeling
of the process of plasma ignition and stabilization of solid fuel combustion was carried out using the PlasmaKinTherm
program. Changes in temperatures, rates, and concentrations of high-temperature binary fuel components along the
length of the plasma–fuel system were revealed. In experiments on plasma ignition of an air mixture of Ékibastuz coal,
a stable torch was obtained, and its temperature, composition, and degree of carbon gasifi cation were determined.
A comparison of the experimental and calculated data showed their satisfactory agreement
Author:
V. E. Messerle, A. L. Mossé, M. N. Orynbasar, A. B. Ustimenkoa
Keywords:
plasma ignition, coal, high-temperature two-component fuel, plasma–fuel system
Page:
116
DISTINCTIVE FEATURES OF THE PYROLYSIS AND GASIFICATION OF BIOMASS IN MICROWAVE HEATING IN A CO2 MEDIUM
The infl uence of a CO2 reactive medium and of a volume in the range 200–600 mL on the yield of basic components (CO, CO2, H2, and CH4) of a producer gas in microwave heating of biomass has been investigated. The dependences of the moderate and maximum concentrations of the gases on the volume of carbon dioxide fed to the chamber of a microwave reactor have been determined. Trends of variation in the concentrations of the enumerated gases with time have been obtained. Times of the onset of release of the concentrations of the gas components and their duration with variation of the CO2 volume fed to the chamber have been established. The infl uence of the feed of reactive gases on the mass of the char has been investigated. It has been shown that the injection of CO2 into the reactor
chamber exerts a positive infl uence on the intensifi cation of microwave pyrolysis of the biomass, with the result that
the yield of volatiles of the formed gas mixture rises.
Author:
G. S. Nyashina, M. A. Kurgankina, A. S. Shvets
Keywords:
biomass, microwave pyrolysis, producer gas, reactive atmosphere, carbon dioxide, waste valorization
Page:
126
OSCILLATORY VISCOMETER FOR MEASURING THE VISCOSITY OF LIQUIDS
Viscosity values of liquids are important for prediction of liquid fl ow in many oil and gas and chemical product
processes. In this paper, a description is given of a number of methods used for measuring the viscosity of liquids,
including the capillary, rotational, oscillatory, and sonic viscometries. A description is also given of a number of
models used for assessing the viscosity of elements, the dependence of viscosity on temperature, and the viscosity
of multicomponent systems, including the Arrhenius equation. The scatter in the data to be found in the literature is
emphasized by comparison of two data reviews on elements.
Author:
P. M. Matyakubova, P. R. Ismatullaev, Zh. U. Shamuratov
Keywords:
physical model, fl ow, moisture content, liquid material, thermosensitive element, heating element, pipeline, heat transfer
Page:
134
THERMAL CONDUCTIVITY OF LIQUID HYDROFLUOROCHLORINE OLEFINS IN THE RANGE FROM SATURATION LINE TO CRITERIAL PRESSURE
A method is proposed for predicting the thermal conductivity of liquid hydrofl uoroolefi ns (HFOs) and hydrochlorofl uoroolefi ns (HCFOs), which belong to the fourth generation of refrigerants, in the range of state parameters from the saturation line to the critical pressure (pcr) and from the triple point of temperature (Ttr) to the critical temperature (Tcr). Within the framework of the methodology, two correlation dependences are proposed approved using the example of describing the thermal conductivity of eight liquid HFO and HCFO refrigerants in the temperature range from Ttr to Tcr. One of the correlations is based on the correlations of S. Yang et al., within the
framework of which we took into account the requirements of the dynamic scale theory of the critical point, with the
other being developed on the basis of the criterion unit of L. P. Filippov. It is shown that both correlations with low
uncertainty describe data on the thermal conductivity of liquid HFO and HCFO refrigerants both on the saturation
line and in the single-phase region. It is also shown that within the limits of experimental uncertainty, the modernized
correlation of S. Yang et al. describes experimental data on the thermal conductivity of propane in the vicinity of
the critical point. Based on the proposed method, tabulated data on the thermal conductivity of liquid refrigerant
R1234ye(E) in the temperature range from 203.15 to 375.15 K were obtained for the fi rst time.
Author:
I. V. Kudryavtseva, S. V. Rykov, I. V. Kudryavtseva, S. V. Rykov
Keywords:
thermal conductivity, refrigerants, hydrofl uoroolefi ns, hydrochlorofl uoroolefi ns, R1234ye(E), correlations, propane, critical point
Page:
142
POSSIBILITIES OF USING DENSE CARBON–CARBON COMPOSITE ON A NONWOVEN WARP IN ION-OPTICAL SYSTEMS OF ION SOURCES
The specifi c features of the structure, as well as the main mechanical and thermophysical properties of a high-density
carbon–carbon composite material based on nonwoven frame are considered. The promise of using this material in
the manufacture of accelerating and emissive electrodes of an ion-optical ion source system is shown. The results of
the operation of an ion-optical system with two sets of electrodes with a diameter of 180 mm with a slot and a circular apertures as part of an experimental ion source HFIS-16IP are presented. Operating modes of the ion source
have been achieved that ensure a minimum half-angle of divergence of the ion beam when operating on xenon and
krypton with diff erent electrode confi gurations. The microstructure and elemental composition of the surfaces of the
electrodes of an ion-optical system were studied after testing the ion source. Comparative studies of electrode surfaces after their high-temperature annealing in vacuum were carried out
Author:
A. B. Elakov, E. A. Bogachev, Yu. S. Perminova, A. I. Mogulkin,b A. V. Mel′nikov, O. D. Peisakhovich
Keywords:
carbon–carbon composite, nonwoven blank, structural homogeneity, ion injector, ion-optical system, electrode
Page:
152
CHARACTERISTICS OF SURFACE DEFORMATION AND FRAGMENTATION OF DROPLETS OF HIGH-VISCOSITY LIQUIDS MOVING IN A GASEOUS MEDIUM
The results of experimental and theoretical studies of the characteristics of surface deformation and fragmentation of droplets of high-viscosity liquids (glycerol and melted Al2O3) moving in a gaseous medium are presented. Typical shapes of droplets, modes, and cycles of surface deformation, cycle durations and the amplitude have been established. Minimum relative velocities of the movement of droplets have been determined leading to fragmentation of droplets of high-viscosity liquids (glycerol and melted Al2O3). The infl uence of a group of factors on the characteristics
of deformation of droplets has been established: fl ow velocity (0–100 m/s) and initial sizes of droplets (1–5 mm).
Satisfactory agreement between experimental data and the results of theoretical calculations for high-viscosity
liquids (using the example of glycerol droplets) was obtained.
Author:
D. V. Antonov, R. M. Fedorenko, V. V. Shekhovtsov, P. A. Strizhak, O. G. Volokitin
Keywords:
high-viscosity liquids, deformation, fragmentation, experiment, modeling, secondary fragments
Page:
161
EXPERIMENTAL ASSESSMENT OF FLOW STRUCTURE IN A CYLINDER DURING AIR FLOW THROUGH POPPET VALVES OF DIFFERENT CONFIGURATIONS
Data are presented on the gas-dynamical structure of fl ow in the cylinder when it is fi lled through poppet valves
with heads in the form of a circle and a square. The studies were carried out on a laboratory setup simulating a
piston internal combustion engine. The air fl ow through the gas-dynamical system of the engine was carried out in
a stationary mode with an initial speed of 8 to 41 m/s. Thermograms of the fl ow structure were obtained for two
control sections of this system using the thermal imaging method. It has been established that the confi guration of the
cylinder valve head exerts a signifi cant impact on the structure in it and that in a cylinder with a round valve there
are pronounced stagnant zones. It has been shown that the use of valves with a square head ensures more uniform
fi lling of the cylinder with air throughout its entire volume compared to a traditional round valve. The data obtained
can be useful for refi ning mathematical models of the process of cylinder fi lling and for developing new methods of
modernizing valve assemblies of piston machines
Author:
L. V. Plotnikov
Keywords:
poppet valve, cylinder, stationary air fl ow, piston engine, thermal imaging
Page:
172
EXPERIMENTAL INVESTIGATION OF THE RANGE OF LARGE-SCALE VORTICES IN THREE-DIMENSIONAL TURBULENT JETS
Results of experiments, demonstrating the possibility of visualization and photograpy of dissipation-scale vortex
elements of a hydrodynamic turbulence, are presented. The reasons for the existence of large-scale vortices
of diff erent types in the initial region of turbulent jets were determined and the infl uence of such vortices on the
velocity distributions of the fl uid fl ows in all the regions of a free turbulent jet with geometric and regime parameters
varying in wide ranges was investigated. The measurements were performed for such a jet in the cases where it
was not subjected and was subjected to an acoustic action, and they were accompanied by the visualization of the
development of large-scale vortices in the initial and transient regions of the jet
Author:
M. S. Isataev, G. Toleuov, Zh. K. Seidulla, M. Sultan
Keywords:
rectangular nozzle, aspect ratio, three-dimensional turbulent jet, large-scale vortices
Page:
179
NUMERICAL SIMULATION OF HEAVY LIQUID FLOW BY THE MULTIDIMENSIONAL NODAL METHOD OF CHARACTERISTICS
A variant of the inverse method of characteristics is presented, in the algorithm of which an additional fractional
time step is introduced, which makes it possible to carry out calculations with a large time step without loss of
accuracy and stability. Calculation formulas of the modifi ed inverse method of characteristics are given for a singlevelocity generalized equilibrium model of a gas–liquid mixture. When calculating multidimensional problems, the
original system of equations is split into a number of one-dimensional subsystems, for the calculation of which a
modifi ed inverse method of characteristics is applied. Using the proposed method, the spreading of a liquid column
under the infl uence of gravitational forces for fl at and axisymmetric cases, as well as a drop of liquid falling into a
hard smooth barrier were calculated. The calculation results are compared with the available experimental data
Author:
V. S. Surov
Keywords:
modifi ed inverse method of characteristics, multidimensional nodal method of characteristics
Page:
186
HYDRODYNAMICS OF A COOLANT IN THE OUTLET SECTION OF A CASSETTE TYPE FUEL ASSEMBLY
The results of experimental studies of the hydrodynamics of a coolant in the outlet section of a cassette fuel assembly
of the RITM reactor of a low-power nuclear power plant are presented. The purpose of the work was to study the
redistribution of axial velocity and coolant fl ow rate at the outlet of the fuel rod bundle, behind the fuel assembly cap,
near the coolant extraction pipe, and in the holes of the upper support plate. To achieve the goal, experiments were
carried out on a research stand with an air working medium on a model of the outlet section of the fuel assembly,
including the outlet fragment of the fuel rod bundle, the cap, the upper support plate with the coolant extraction
pipe. When conducting research, the pneumometric method and the method of injection of a contrast impurity were
used. An area covering the entire cross section of the model was chosen as the study area. The picture of the coolant
fl ow is represented by cartograms of the distribution of axial velocity and coolant fl ow rate, as well as cartograms
of the distribution of the contrast impurity. The experimental results can be used in the design of new active sections
of RITM reactors. The resulting experimental base can be used for local validation of CFD programs and onedimensional thermal-hydraulic codes used to substantiate the thermal reliability of cores.
Author:
S. M. Dmitriev, T. D. Demkina, A. A. Dobrov, D. V. Doronkov, D. S. Doronkova, A. N. Pronin, A. V. Ryazanov, D. N. Solntsev, and A. E. Khrobostov
Keywords:
nuclear reactor, core or active section, fuel cassette, fuel rod or element, spacer grid, cap or head, coolant extraction pipe, axial velocity, axial fl ow rate, contrast impurity
Page:
195
METHOD OF DETERMINING THE PARAMETERS OF A VORTEX TUBE TO COOL AIRCRAFT EQUIPMENT
A method has been proposed that allows calculating the parameters of a vortex cooling system for aircraft equipment
as functions of fl ying conditions. The optimum confi guration and the dimensions of basic elements of the vortex tube
have been determined. By the numerical-modeling method, the operating parameters of the vortex system have been
obtained. The adequacy of a computational model has been checked
Author:
I. A. Potapov, A. V. Kositsyn
Keywords:
vortex tube, numerical modeling, natural experiment, cooling eff ect
Page:
204
INVESTIGATION INTO HIGH-VELOCITY INTERACTION WITH A STEEL BARRIER BY TUNGSTEN CARBIDE ALLOY STRIKERS WITH A CONE-SHAPED NOSE
An analytical-experimental method has been used to investigate the penetrative capability of cylindrical VNZh-90
and VNZhK + 75% VK8 with fl at heads and conical noses in interaction with a steel barrier in the velocity range
of 1200–1300 m/s. Calculation results are presented for interaction of the considered strikers with steel barriers at
impact velocities of up to 2000 m/s
Author:
A. N. Ishchenko, V. V. Burkin, N. N. Belov, Ya. D. Lipatnikova, A. Yu. Sammel′, A. B. Skosyrskii, E. Yu. Stepanov, N. T. Yugov
Keywords:
high-velocity interaction, kinetic striker, barrier, mathematical model
Page:
213
MODELING IMPACT INTERACTION OF A COMPOSITE BARRIER WITH A SPHERICAL STRIKER
A mathematical model has been constructed and verifi ed for the behavior of a composite barrier under the conditions
of shock-wave loading. An analytical-experimental method has been used to assess the eff ects of a modifi ed composite
barrier in high-velocity interaction with a spherical steel striker in the velocity range of 500–1200 m/s.
Author:
A. S. Plyaskin, N. N. Belov, N. T. Yugov, G. P. Tonkikh, É. S. Useinov, A. I. Babarykina, A. N. Ishchenko, V. V. Burkin, A. Yu. Sammel′, E. Yu. Stepanov, A. V. Chupashev
Keywords:
high-velocity impact, composite barrier, spherical striker, mathematical modeling
Page:
217
EXPERIMENTAL-THEORETICAL ASSESSMENT OF THE MINIMUM VELOCITY OF THROUGH PENETRATION OF AN UNDERWATER STEEL BARRIER BY A SUPERCAVITATING STRIKER
An experimental-theoretical assessment has been made of the minimum required velocity for through penetration
of 20–60 mm thick steel barriers by a supercavitating VNZR-95 alloy striker. Parametric calculations have been
conducted within the framework of an elastic-perfect plastic Prandtl–Reuss model
Author:
V. V. Burkin, A. S. D′yachkovskii, A. N. Ishchenko, A. Yu. Sammel′, E. Yu. Stepanov, M. V. Khabibullin, A. V. Chupashev
Keywords:
mathematical modeling, high-velocity interaction, supercavitating striker, steel barrier
Page:
223
INVESTIGATION OF THE PLASTIC DEFORMATION OF A ROTATING DISK FROM AN ALLOY REINFORCED WITH INCOHERENT NANOPARTICLES
An investigation has been conducted into the plastic deformation of a rotating disk from aluminum-based dispersionhardened alloy. The eff ects of the size of strengthening particles on a material′s strength properties have been
identifi ed. Simulation results show that the strengthening of a material with nanoparticles change substantially
strength characteristics. In alloys with shorter distances between the strengthening particles, a high disk rotation
frequency is required for achieving plastic deformation at one and the same volume fraction of particles. With increase
in temperature the material plasticizes more, i.e., it becomes more yielding, which is accompanied by a reduction in
the material fl ow stress. As a result, a decrease occurs in the rotation frequency at which plastic deformation begins.
With increase in the inner and external radii of the disk, at its one and the same width, the disk′s resistance to plastic
deformation decreases, and the beginning of plastic deformation occurs at a lower rotation frequency.
Author:
O. V. Matvienko, O. I. Daneyko
Keywords:
dispersion-hardened materials, nanodimensional particles, stress–strain state, strain hardening, plastic deformation, mathematical model
Page:
229
INFLUENCE OF THE IRRADIATION, BY A PULSED ELECTRON BEAM, OF THE SURFACE OF SILUMIN AK5M2 AS PART OF A METAL/CARBON-FIBER-REINFORCED-PLASTIC COMPOSITE ON MECHANICAL PROPERTIES
The authors have presented results of uniaxial-tension testing of specimens of the layered composite "silumin/carbonfi ber-reinforced-plastic" (AK5M2/CFRP). AK5M2-grade silumin of hypoeutectic composition with the irradiation
of the specimen′s surface by a pulsed laser beam was taken as the basic material. To create layered composites,
carbon unidirectional fabric "CARBONWRAP Tape 230" produced at the Joint Stock Company Nanotechnological
Center of Composites (NCC) was glued to the silumin surface. The binary epoxy compound "CARBONWRAP Resin
530+" produced at NCC was used as the binder. The uniaxial tension test of the specimens was implemented on
an INSTRON 3382 testing machine at an extension rate of 0.3 mm/min. The evolution of deformation fi elds on
the specimen′s surface was obtained using a VIC-3D digital optical system based on the method of correlation of
digital stereoscopic images. From the testing results, the diagrams of deformation under uniaxial tension of the
AK5M2/CFRP were constructed. The electron-microscopic image of the silumin surface layer was obtained by
the scanning-electron-microscopy methods. An analysis of the structure of its infl uence on the physicomechanical
properties was performed. An analysis of the strained state of the specimens was made by the patterns of distributions
of longitudinal and transverse deformations in space and time
Author:
A. M. Ustinov, A. A. Klopotov, Yu. F. Ivanov, A. D. Teresov, E. A. Petrikova
Keywords:
silumin of hypoeutectic composition, irradiated surface, high-speed crystallization, rapid cooling, electron beam, layered composite "silumin/carbon-fi ber-reinforced-plastic," strained state, deformation fields
Page:
241
CHARGING ELECTRICAL CAPACITANCE CORRESPONDING TO THE MINIMUM OF DISSIPATIVE LOSSES
The problem on the law of charging a nonlinear electrical capacitance (storage cell, capacitor) that would
correspond to the minimum of dissipative energy losses has been solved. The duration of the process, the fi nal
and initial energy reserves are fi xed. It is shown that the relationship between the charging current and the
voltage across the capacitance for the optimal charging law is the same for any dependences of the capacitance
on voltage.
Author:
A. M. Tsirlin, M. A. Zaeva
Keywords:
nonlinear electrical capacitance, charger, dissipative losses of energy, charging current, optimal charging
Page:
253