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Enthalpy and heat capacity of liquid Na15Pb4 and Na50Pb50 alloys Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-03-20 A. R. Khairulin, S. V. Stankus
Using an isothermal drop calorimeter, the enthalpy increment of the Na15Pb4 and Na50Pb50 alloys was measured and the heat capacity was determined in the temperature range of 420–1075 K, including the solid and liquid states. It has been established that the values of the heat capacity of melts significantly exceed the calculations of this value according to the laws for an ideal solution, and this
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Modulation of flow meandering in the gap of a model of a peripheral subchannel of a fuel rod assembly Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-03-20 M. V. Shestakov, M. V. Tokarev
Fuel rod assemblies with tight lattice bundles are considered promising for increasing the conversion rate and heat transfer in small modular reactors. The main feature of the flow in a tight lattice rod bundle is the formation of quasi-periodic large-scale velocity oscillations in the gap between fuel rods. These oscillations enhance mixing between the subchannels and significantly increase heat transfer
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Simulation of heating of the sensitive element of the heat flux sensors in a high-velocity flow under variable input conditions Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-03-20 I. R. Vasnev, M. A. Goldfeld, N. N. Fedorova
The paper presents the results of numerical simulations of high-velocity turbulent air flows in a plane channel with a variable cross section exhibiting sudden expansion with allowance for coupled heat transfer with copper plates modeling the sensitive elements of heat flux sensors. The simulations are performed for conditions of a high-enthalpy short-duration wind tunnel whose specific features are
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Experimental study of the motion and shape of a vapor bubble rising in an annular channel at subatmospheric pressure Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-03-20 R. A. Dekhtyar, V. V. Ovchinnikov
Experimental study was performed for the dynamics of vapor bubble rising in the annular channel at subatmospheric pressure. The gas bubble is formed during boiling of superheated degassed liquid in an annular channel restricted by two glass tubes with the diameters of 25 and 16 mm. It was demonstrated that the dynamics of vapor cavity while rising the vapor bubble in the annular channel demonstrates
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Numerical simulation of gas dynamics of the inflow into a channel located behind a conical or plane shock wave Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-03-20 V. I. Zvegintsev, I. I. Mazhul
The paper presents the results of a numerical study of gas dynamics and integral parameters of the flow at the channel entrance located behind a conical or plane shock wave. The freestream Mach number range is M = 2–4 and the range of the angles of the compression surfaces of the wedge and cone is δ= 10–90°. Data on the flow structure at the channel entrance, mass-averaged Mach numbers, total pressure
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Formation of a separation vortex in the vicinity of a dihedral corner configuration at M∞ = 2.27 and α ≤ 6° Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 A. I. Maksimov, I. N. Kavun
The article considers the development of a near-wall separation vortex arising at a supersonic flow around the external dihedral corner due to the pressure drop between its faces, in the range of angles of attack α = 0.5°–6°. The processes of the origin and development of separation and secondary vortices at the angle increase are investigated in detail. Particular attention is paid to the flow structure
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Thermal boundary conditions at the fluid–solid interface in the case of a conducting body: a novel thermal lattice Boltzmann analysis Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 Y. Dahani, A. Amahmid, M. Hasnaoui, S. Hasnaoui, A. El Mansouri, I. Filahi
In this paper, a novel thermal lattice Boltzmann approach is proposed for the implementation of the thermal boundary conditions at the fluid-solid interface. The numerical code, developed on the basis of the new approach, was validated against reliable numerical data from the literature in the cases of both square and circular conducting blocks. Analytical and experimental validations were also performed
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The single-phase swirling flow simulation in a heat exchange channel with coolants counterflow at the operation parameters of PWR Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 S. M. Dmitriev, A. E. Sobornov, R. R. Ryazapov, A. V. Kotin, N. V. Matsin
The results of experimental and computational studies of the processes of hydrodynamics and heat transfer of a swirling flow, heated by the counter coolant flow in the heat exchange channel under standard technological parameters of a nuclear power plant are presented in this paper. The temperature field of the heat exchange channel as a whole and the coefficient of hydraulic resistance of channels
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Solubility of crystalline tricosane in supercritical CO2 and CO2 + cosolvents Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 I. Sh. Khabriev, L. Yu. Sabirova, I. Z. Salikhov, L. Yu. Yarullin, V. F. Khairutdinov, T. R. Bilalov, I. M. Abdulagatov
The paper presents the results of experimental study of the solubility (VLE-properties) of crystalline tricosane in pure and modified supercritical carbon dioxide over the temperature range from (308.15 to 315.15) K and at the pressures from (8.00 to 20.32) MPa using the dynamic method. Modification of carbon dioxide fluid was performed by adding several organic solvents, such as dimethylsulfoxide
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Study of a regenerative cooling system while using heat-conductive metal nanoparticle suspension in n-decane Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 K. Yu. Arefiev, A. M. Saveliev, A. V. Voronetskii, S. V. Kruchkov
The paper presents the calculation estimates for efficiency of regenerative cooling for a model cylinder-shaped flow duct using a suspension of heat-conductive metal nanoparticles in n-decane as fuel/coolant. We adapted a standard mathematical model of conjugated heat transfer that accounts for thermophysical properties of the metal nanoparticle suspension and n-decane. The data are presented for heating
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Effect of heat losses in the temperature transducer in measurements in hotshot wind tunnels Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 I. S. Tsyryulnikov, T. A. Korotaeva, A. A. Maslov
The study is aimed at measuring the gas flow temperature by thermocouples whose time of reaching the equilibrium temperature is comparable with the measurement time, and heat release to structural elements of the transducer can be rather large. The results of numerical simulations of the gas flow in the temperature transducer used for measuring the stagnation temperature in high-enthalpy hotshot wind
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Boundary-layer control on a body of revolution with a large aspect ratio by means of distributed air blowing Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 V. I. Kornilov
Results of studying the process of air blowing through a perforated section of the surface on an axisymmetric body with an aspect ratio of 25.3 in an incompressible flow with the Reynolds number ReL = 4.36·106 are reported. The blowing coefficient Cb is varied in the interval from zero to 0.00885. It is shown that distributed blowing through a perforated wall with improved geometry ensures a significant
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Density and thermal expansion of indium–lead melts Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 R. N. Abdullaev, R. A. Khairulin, S. V. Stankus
The volumetric properties of liquid indium-lead alloys containing 20 and 33 at. % Pb have been measured using gamma-ray attenuation technique at temperatures from the liquidus line to 880 K. The density changes of these alloys during solid–liquid phase transition have been calculated. The obtained experimental values of the molar volume and the volumetric thermal expansion coefficient of melts and
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Thermophysical and physicochemical basis for hydrogen production in compact energy systems of low-carbon economy Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 V. V. Kuznetsov, O. A. Gasenko
Physicochemical and thermal processes occurring during methane conversion into synthesis gas under non-isothermal conditions in microstructural heat exchanger-reactors based on microchannels are considered in this paper. A method for synthesizing a rhodium-based composite thin-layer catalyst for steam reforming of methane and carbon monoxide is proposed, and the results of experimental and numerical
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Mathematical modeling of self-excited oscillations over the pitch of a conical-spherical body at Mach number M = 1.75 using the forced-oscillation hypothesis Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 E. A. Chasovnikov
With the aim to model the self-excited oscillations of a body, a hypothesis is proposed for the formation of periodic bottom-wake vortex structures whose frequency coincides with the natural frequency of oscillations of the body, and the force effect of the oscillations on the body is mathematically described with a harmonic function of time. Analytical formulas for aerodynamic derivatives and equivalent
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Simulation of the laser welding of porous and monolithic metallic plates Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 V. N. Popov, A. N. Cherepanov
Numerical simulation of unsteady processes proceeding during the laser welding of plates made of porous and monolithic (non-porous) metals was carried out. The influence of the welding speed on the quality of resultant welded joints and seam morphology was studied. The calculated characteristics of connections between porous and monolithic stainless-steel plates are in qualitative agreement with the
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Influence of the pressure of a propane-butane mixture on the morphology of carbon nanomaterial formed in an arc discharge Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-02-13 M. A. Morozova, A. V. Ukhina, A. V. Zaikovskii
The morphology of carbon material formed in an arc discharge in a mixture of i-butane, n-butane, and propane when spraying a graphite-nickel electrode was studied. The experiments were carried out with changing the gas medium pressure. Carbon globules, graphene structures, and carbon nanotubes have been discovered. It was found that at pressures of 75 and 400 torr, carbon globules predominate in the
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Effect of ribbing of the internal rotating cylinder in the Couette–Taylor system on the value of rotational resistance moment Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 V. N. Mamonov, N. B. Miskiv, A. D. Nazarov, A. F. Serov, V. I. Terekhov
The experimental results on the effect of longitudinal ribs on the rotational resistance moment for the Couette–Taylor flow between two rotating cylinders are presented. The tangential Reynolds number in the experiments was varied by changing the velocity of cylinder rotation and the working fluid (water-glycerin solution) viscosity. The experiments covered laminar, transient, and turbulent flow regimes
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Calculation of gas inflow into a vacuum vessel Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 V. I. Zvegintsev, S. V. Lukashevich
Based on the hypothesis of quasi-stationarity, relations were obtained for calculating the unsteady process of filling a vacuum vessel with a gas. As a criterion for the completion of the filling process, the admissible degree of pressure increase in the vacuum vessel was adopted. An analysis was made of the possibilities of increasing the duration of the filling process for a vacuum vessel of a given
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Two-dimensional steady-state traveling waves on the surface of a vertical rivulet Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 S. P. Aktershev, S. V. Alekseenko, A. V. Bobylev
Nonlinear waves in a rectilinear rivulet flowing down a vertical plate are investigated on the basis of the developed semi-analytical model. The characteristics of nonlinear quasi-two-dimensional steady-state traveling waves are obtained numerically. Another wave family (the family of double-humped waves), branching off from the first family by doubling the spatial period, is found for small values
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Effect of vibrational nonequilibrium of supersonic jets of CO2 on their gas-dynamic structure Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 I. S. Tsyryulnikov, S. G. Mironov, T. V. Poplavskaya
A nonisobaric supersonic jet of vibrationally excited carbon dioxide exhausting from converging axisymmetric nozzles with the diameter ranging in a wide interval (from 0.03 to 114 mm) is studied experimentally and numerically. Numerical simulations are performed within the framework of the two-temperature approach with the use of the Landau–Teller relaxation equation for each vibrational mode of carbon
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Volumetric properties of liquid and solid LiF–KF mixtures Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 R. A. Khairulin, R. N. Abdullaev, S. V. Stankus, A. B. Meshalkin
The density of liquid mixtures of lithium and potassium fluorides with a content of 51.2 and 71.1 mol % LiF was measured using gamma-ray attenuation technique in the temperature range from liquidus to 1000–1190 K. For a mixture of near-eutectic composition (51.2 mol % LiF), the relative density change during the solid–liquid phase transition and the density in the solid state near the melting point
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Effect of barodiffusion on the dynamics of gas bubble growth in the magmatic melt Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 A. A. Chernov, M. N. Davydov, S. I. Lezhnin
The effect of barodiffusion on the dynamics of gas bubble growth in a highly viscous, gas-saturated magmatic melt undergoing rapid decompression is studied. A mathematical model of the process, which represents a joint dynamic and diffusion problem, is proposed. It is shown that as the bubble grows, a diffusive boundary layer is formed around it, leading to the appearance of a large viscosity gradient
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Opportunities for using the thermal imaging method of nondestructive inspection for skin delamination diagnosis in honeycomb structures used in modern aircraft Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 N. I. Klochkov, I. D. Zverkov, D. A. Gavrilov
The modern aviation industry has many applications for honeycomb composite panels (HCP). The HCP-manufactured product line becomes more extended. This dictates a need for most effective and inexpensive methods for nondestructive inspection for HCP integrity that can ensure a high level of flight safety. One of promising methods for nondestructive inspection is the thermal technique. This paper presents
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Influence of radiation on the formation of wind and temperature regimes in urban environment Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 K. Yu. Litvintsev, A. A. Dekterev, V. D. Meshkova, S. A. Filimonov
In the present paper, a computational study of the influence of solar and thermal radiation on the formation of wind and temperature conditions in urban environment is carried out using the example of an urban area of Krasnoyarsk in winter. For calculations, a developed microscale mathematical model of urban atmosphere was used. The calculation results showed that the presence of radiation in the daytime
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The influence of calcium addition on thermophysical properties and thermodynamic functions of aluminum alloy AlCu4.5Mg1 Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 I. N. Ganiev, R. S. Shonazarov, A. Elmurod, U. N. Faizulloev, A. G. Safarov
The cooling rates of the studied alloy samples were determined in the “cooling” mode by constructing thermograms of cooling alloys and their subsequent differentiation. Considering the heat capacity of the standard (Al brand A5N) and the cooling rates of the samples and the standard, the temperature dependence of the heat capacity of the aluminum alloy AlCu4.5Mg1 doped with calcium was calculated.
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The dynamics of the interfacial surface of helium II–vapor in a U-shaped channel Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 Yu. Yu. Puzina, A. P. Kryukov
The paper considers experimental data on the dynamics of superfluid helium in a U-shaped cylindrical channel. An experimental cell and a methodology for investigations, parameter measuring, and obtained data processing are described. When a heat flux is applied near the heater, vapor can appear, and the interfacial surface executes regular oscillations of macroscopic amplitude with a constant frequency
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Development of disturbances generated by an electric discharge in the shock wave / boundary layer interaction zone Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 O. I. Vishnyakov, P. A. Polivanov, A. A. Sidorenko, A. D. Budovsky
The paper presents the results of experimental study of disturbances generated by an electric discharge. Observations are carried out in the zone of interaction of a shock wave and a boundary layer (the incident shock wave has the Mach number M = 1.43). Experiments were carried out in a supersonic wind tunnel with the unit Reynolds number Re1 = 11·106 1/m. The flow velocity was measured using the PIV
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Influence of heat interaction modelling on the efficiency of endoreversible closed regenerative solar Brayton cycles Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 S. Sabzpoushan, M. R. Morad
In endoreversible cycles, irreversibility is considered only between the systems and their surroundings. In this paper, the modelling of heat interaction with a solar regenerative Brayton cycle is studied with regard to various fidelities based on the first and second laws of thermodynamics. The effect of linearity and nonlinearity related to both convective and radiative heat interactions with the
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Heat transfer and hydraulic resistance of a flat channel with discrete wall roughness in the form of inclined trench dimples Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 I. A. Davletshin, N. S. Dushin, O. A. Dushina, N. I. Mikheev, R. R. Shakirov, S. A. Isaev
An experimental study of heat transfer and hydraulic losses in a channel with one wall being a surface with trench dimple was carried out. The working surface had four rows of dimples located alternately at angles of 45° and −45° to the channel axis. In the laminar regime, the transfer of heat and the losses of pressure turned out to be close to the parameters of a smooth channel. In the turbulent
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Plasma-chemical waste processing: numerical analysis and experiment. Part 4. Ash-and-slag waste and oil refinery wastes Thermophys. Aeromech. (IF 0.5) Pub Date : 2024-01-03 V. E. Messerle, O. A. Lavrichshev, A. B. Ustimenko
The results of thermodynamic calculations and experimental studies on plasma processing of ash-and-slag wastes and oil refinery wastes with production of fuel gas and inert mineral material are presented. The calculated and experimental data on plasma-chemical processing of oil refinery wastes are compared.
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Aerothermodynamic design optimization of planetary vehicle Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 S. Shivank, S. Harshul, N. A. Hammad, G. Malaikannan
The present work deals with the design optimization of different vehicle configurations for planetary entry. Choosing the aerothermodynamic characteristics of heat flux and drag as the objective function we have analyzed and simulated the effects of atmospheric resistance on planetary entry vehicles in the rarefied atmosphere. We have utilized the SPARTA (Stochastic PArallel Rarefied-gas Time-accurate
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Laminar mixed convection in a vertical flat channel with constant wall temperature Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 E. P. Valueva
The problem of laminar mixed convection is considered in a flat vertical channel with upward and downward flow and liquid heating, i.e., for the cases of coincidence of the directions of free and forced convection, as well as their opposite directions. The system of equations of motion, continuity, and energy is solved by the finite difference method. Data on the profiles of the longitudinal velocity
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Direct Monte Carlo simulation of subsonic evaporation into a half-space Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 A. A. Morozov, E. Ya. Gatapova
Modeling of processes with phase transition in confined spaces needs high-accuracy simulations with account for non-equilibrium. In the present paper, we use the direct simulation Monte Carlo method for describing evaporation into a vapor-filled half-space with a subsonic monoatomic gas flow. Two types of boundary conditions for open halfspace are considered: the iteration approach with consecutive
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Numerical study of the influence of bichannel-system geometry on the existence domain of Hartmann effect Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 A. A. Zhilin, A. V. Primakov
The present numerical study is aimed at revealing the influence of the nozzle exit-to-resonator edge distance on the gas-dynamic characteristics of the acoustic-convective flow in the flow path of a bichannel system. The aim of the work is the development of a computational technology for describing physical processes in the duct of multichannel systems that generate high-intensity acoustic fields
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Effect of argon on microwave plasma chemical vapor deposition of diamond coatings from an H2+CH4+Ar mixture activated in a microwave discharge Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 A. A. Emelyanov, V. A. Pinaev, M. Yu. Plotnikov, A. K. Rebrov, N. I. Timoshenko, I. B. Yudin
Results of an experimental study of the influence of argon addition on microwave plasma chemical vapor deposition of diamond from a hydrogen-methane mixture are reported. A specific feature of this method is the use of a high-velocity jet for transporting gases activated in a microwave plasma in the discharge chamber to the substrate located in the deposition chamber. Optical emission spectroscopy
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Linear thermal expansion coefficient of gallium garnets Gd3Ga5O12, Gd3.04Sc1.8Ga3.16O12, and Ca3Nb1.5Ga3.5O12 Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 Yu. M. Kozlovskii, S. V. Stankus
The results of an experimental study of the thermal expansion of gallium garnets Gd3Ga5O12, Gd3.04Sc1.8Ga3.16O12, and Ca3Nb1.5Ga3.5O12 in a wide temperature range (293.15–1473 K) are presented. A noticeable effect of niobium in the structure of gallium garnets on the thermal expansion coefficient has been found. The temperature dependences of the volumetric properties have been obtained.
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Caloric properties of the Mg2Ca intermetallic compound in solid and liquid states Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 R. N. Abdullaev, A. R. Khairulin, A. Sh. Agazhanov
The enthalpy and heat capacity of solid and liquid Mg2Ca intermetallic alloy were measured by massive high-temperature isothermal drop calorimeter over the temperature range of 298.15–1177 K. The estimated errors in the data on enthalpy and heat capacity were 0.2 % and 2 %, respectively. The fusion enthalpy of the Mg2Ca intermetallic alloy was determined to be 483 ± 3 J/g. The heat capacity of the
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Experimental study of interfacial mass transfer in a slug flow of ethanol — CO2 mixture in a rectangular microchannel Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 G. V. Bartkus, N. A. Filatov, A. S. Bukatin, V. V. Kuznetsov
The structure of a slug gas-liquid flow and interfacial mass transfer during the flow of ethanol-N2 and ethanol-CO2 mixtures in a horizontal rectangular microchannel have been experimentally studied. The experiments were carried out in a straight microchannel with a cross section of 380·190 µm. To determine a change in the volume of a gas bubble along the microchannel length, the method of high-speed
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Temperature field in a well with casing induction heating: considering the natural convection influence Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 R. Z. Akchurin, F. F. Davletshin, D. F. Islamov, R. A. Valiullin, R. F. Sharafutdinov
One of the promising methods of geophysical research in operating wells is active thermometry. The method consists in creating an artificial temperature field in a well due to local heating of the metal casing. Observation of heat tags movement enables determining the fluid flow rate in the well and identifying the intervals of the behind casing flow. The article is devoted to the study of non-stationary
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Determination of the effect due wall interference on the flow around airfoil in the T-128 wind tunnel Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 S. A. Glazkov, A. V. Semenov
Within the framework of linear subsonic theory, the problem of determining the effect due to wall interference on the flow around airfoil according to the pressure distributions measured on the airfoil and on the wind-tunnel test section walls is solved. For the test case (testing a BGK1 airfoil in the IAR1.5m wind tunnel), we compared the wall interference corrections to freestream Mach number and
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Improving the accuracy of temperature measurement by a spectral ratio pyrometer Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 A. V. Frunze
The paper describes an algorithm that using numerical methods allows calculating the relationship between the temperature of the spectral ratio and the actual temperature of a “non-gray” object, which takes into account not only the dependence of the spectral emissivity of the object on the wavelength, but also its temperature dependence, inherent in almost all real objects (materials). This algorithm
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Effect of initiating additives on phenol oxidation in water–oxygen fluid Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 A. V. Shishkin, S. A. Alekhin, M. Ya. Sokol
Phenol oxidation in a water-oxygen fluid in a tubular batch reactor with its uniform heating (1 °C/min) to 600 °C was studied. An increase in the amount of O2 above the stoichiometric ratio by 25 % leads to an increase in the degree of carbon burnout by the factor of 1.09. Replacing 10 % of the stoichiometric amount of oxygen with nitrous oxide leads to the same increase in the degree of carbon burnout
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Effect of random factors on liquid flow over the sheets of a structured packing Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 B. V. Perepelitsa
The flow of liquid over the corrugated sheets of regular packings largely determines the processes of heat and mass transfer in distillation columns. An important role in the distribution of liquid over the structured packing sheets is played not only by the characteristics of packing surface microtexture, but also by the drip point location in the liquid distributor relative to the sheets in the structured
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Plasma-chemical waste processing: numerical analysis and experiment. Part 3. Rubber of used tires Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 V. E. Messerle, O. A. Lavrichshev, A. B. Ustimenko, M. N. Orynbasar
Here we present the results of thermodynamic and kinetic calculations as well as experimental studies of plasma processing of rubber powder of recycled tires, demonstrating the promise of using the plasma-chemical technology for gasification of this powder with the production of energy gas. The results of experiment and calculations were compared and showed good agreement.
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Some thermodynamic properties of SF6 on the binodal in the vicinity of the critical point Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 E. E. Ustyuzhanin, V. F. Ochkov, V. A. Rykov, S. V. Rykov, I. V. Kudryavtseva
The presented paper considers a number of problems, with the first of them concerning the analysis of experimental (ρl, ρg, T)-data of SF6 at relative temperatures (1.5·10−8 < τ < 0.3). The second task is to develop combined models (ρl (D, C, τ), ρg (D, C, τ), …) that agree with a number of boundary conditions, including the requirements of the scale theory of critical phenomena. The third task deals
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Analysis of factors determining numerical solution in the calculation of flow with combustion using the ONERA experimental model Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-10-23 W. Liu
Three-dimensional numerical simulation of a transverse hydrogen jet blowing into a duct with a supersonic flow of air (warmed by a fire heater) has been carried out. The study is based on experimental data obtained at the ONERA-LAERTE facility. The RANS equations for the reacting gas were solved, closed by the SST model and various kinetic mechanisms of hydrogen combustion in air. The channel wall
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Formulation of approximate analytical solutions for a heat transfer model for an ice layer during microwave heating Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract The research considers the microwave treatment of snow-and-ice mass comprising the stages of heating and melting. A nonlinear mathematical model for two-phase Stephan problem was developed for the case of sandwich dielectrics system. We offer approximate analytical solutions that take into account the thermophysical and electrophysical properties of dielectric layers; this approach allows
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Hysteresis induced by interaction of oblique hydraulic jumps on shallow water Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract Reflections of hydraulic jumps on shallow water are studied. Theoretical criteria of the transition between the regular and Mach reflections are derived, and it is shown that there is a domain of angles of incidence where both types of reflection are possible. Numerical simulations reveal a hysteresis of this transition, which is consistent with theoretical predictions. It is shown that the
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Direct stochastic simulation of a rarefied gas flow in channels of variable cross section Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract Rarefied gas flow into a vacuum through short linearly diverging and converging channels has been examined with the direct simulation Monte Carlo method. Solution to the problem has been suggested using complete geometric setup with quite large areas on inlet and outlet of a model channel in examined geometry. A mass flow rate through the channel and flow field both inside the channel and
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Secondary flows in a flat diffuser and their significance for the formation of a turbulence field Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract Turbulent flows in a flat diffuser are characterized by the presence of two local maxima in the profiles of longitudinal velocity pulsations. The mechanism of the formation of a turbulent flow structure in a flat diffuser was experimentally studied. For this purpose, the parameters of the flow kinematic structure in a diffuser with an opening angle of 2.5° were measured. The profiles of velocities
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Studying the development and interrelation of transfer processes during the combustion of a hydrogen jet flowing from a slit into the air Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract This work examines the transition from kinetic to diffusion combustion using optical diagnostic methods. Experimental data were obtained on the temperature fields, composition and velocity of gas near the leading edge of a hydrogen flame flowing from a 2×20 mm slit into the air. The distribution of the rate of combustion product formation, the intensity of heat release and pressure was obtained
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Study of the transient gas outflow from a container Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract An experimental study of the flow of air from a container through throttling tubes of various configurations with characteristic times from 0.6 to 9 s was carried out. The equivalent container-outlet area was determined based on the ratio of the length of the throttling tube to its nominal diameter. It was found that during the outflow, the gas temperature inside the container decreased by
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Thermal conductivity of Novec 7100 in vapor phase Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract Thermal conductivity of a Novec 7100 fluid sample was measured by the steady-state method of coaxial cylinders. Experiments were performed in the temperature range 350–385 K and pressure range 0.12–0.21 MPa. The error for experimental data on thermal conductivity is about 1.5–2.5 %. The error in measuring temperature and pressure was less than 0.05 K and 4 kPa, correspondingly. The general
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An OpenFOAM-based evaluation of various wall treatment strategies in simulating separated flows past bluff bodies with heat transfer Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-09-01
Abstract The effect of wall treatment on the performance of k-ε model in incompressible, turbulent, separated flows with and without heat transfer has been evaluated in this study. We have simulated two benchmark cases: (i) flow past a circular cylinder at Re = 3900, and (ii) flow past a heated square cylinder at Re = 21 400 using the open source CFD package: OpenFOAM. We have compared three variants
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Numerical study of the influence of local foreign-gas injection on the linear stability of compressible boundary layer Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-08-17 S. O. Morozov, S. V. Lukashevich, A. N. Shiplyuk
This work is devoted to a numerical study of the influence of foreign-gas injection on the stability of compressible boundary layer on a concave surface. The stability calculation was carried out within the framework of the locally parallel linear stability theory. The results of calculations for the reference case without injection showed that Görtler vortices and the second Mack mode exhibited the
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Mathematical model of heat transfer in a dielectric layer under microwave irradiation Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-08-17 V. A. Karelin, V. V. Salomatov
This paper considers the microwave processing for snow-ice mass comprising the heating and melting stages. The search for basic patterns of these processes aimed at optimization, control, and the design of stages is based on mathematical models and their implementation using analytical or numerical methods. A nonlinear mathematical model of the two-phase Stefan problem for a layered system of dielectrics
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Au-induced crystallization of non-stoichiometric amorphous silicon oxide initiated by nanosecond laser pulses Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-08-17 F. A. Samokhvalov, N. I. Smirnov, A. A. Rodionov, A. O. Zamchiy, E. A. Baranov, Yu. G. Shukhov, A. S. Fedotov, S. V. Starinskiy
Thin films of polycrystalline silicon are widely used in semiconductor industry. One of the methods for obtaining such structures on cheap and low-melting substrates is metal-induced crystallization, since the use of a metal (for example, Au) as a catalyst during crystallization of an amorphous semiconductor allows a considerable reduction of annealing temperature. However, the typical duration of
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Influence of the leading-edge bluntness radius of a plate on the response of flat-plate boundary layer to an N-wave at Mach number M = 2 Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-08-17 A. D. Kosinov, N. V. Semionov, A. A. Yatskikh, V. L. Kocharin, A. V. Shmakova
An experimental study of the influence of the leading-edge radius of a blunt plate on the response of boundary layer on this plate to an N-wave at Mach 2 was carried out. Three flat-plate models with different leading-edge bluntness radii, r = 0.05, 0.5, and 2.5 mm, were used in the experiments. The oncoming-flow disturbances were created using a generator provided on the sidewall of the test section
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Experimental study of urotropine gasification in CO2 flow at different temperatures Thermophys. Aeromech. (IF 0.5) Pub Date : 2023-08-17 E. A. Salgansky, A. Yu. Zaichenko, D. N. Podlesniy, M. V. Tsvetkov
The gasification of solid urotropine was experimentally studied at filtering a high-temperature flow of carbon dioxide through it. It was shown that with an increase in the temperature of the filtered gas from 650 to 920 K, the time of urotropine gasification decreased and the average gasification rate increased from 0.38 to 1.25 g/s, leading to an increase in the flow of urotropine gasification products