

Home – Home – Jornals – Journal of Applied Mechanics and Technical Physics 2022 number 5
2022 year, number 5
A. S. Vereshchagin^{1,2,3}, I. V. Kazanin^{1,2}, V. N. Zinoviev^{1}, V. M. Fomin^{1,2}
^{1}Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia ^{2}Novosibirsk State University, Novosibirsk, 630090, Russia ^{3}Novosibirsk State Technical University, Novosibirsk, 630073, Russia
Keywords: composite sorbent, helium, microspheres, membranesorption method, numerical simulation, shortcycle adsorption, hyperbolic model
Abstract >>
A hyperbolic character of the convective part of the flow of an airhelium mixture through a granulated sorbent layer with allowance for the Forchheimer filtration is demonstrated. A numerical model of a onedimensional flow of the airhelium mixture through an adsorber filled by a granulated sorbent with due allowance for air and helium diffusion inward cylindrical granules and helium confinement in microspheres. Within the framework of this model, verification of a numerical algorithm in problems of gas filtration through a porous medium and propagation of a pressure wave formed by the incident shock wave over a gas medium is performed. Experimental and numerical data are obtained and are found to be in good agreement. The enrichment phase is modeled by the method of shortcycle adsorption with the use of a bifunctional sorbent based on microspheres. It is demonstrated that the mass fraction of helium in the airhelium mixture can be almost doubled (from 0.7 to 1.3%)with the helium extraction degreeof 9 0.4%.

S. Yu. Petryakov^{1}, D. N. Mirkhanov^{1}, A. F. Gaisin^{2}, R. Sh. Basyrov^{1}, N. F. Kashapov^{3}
^{1}Kazan National Research Technical University named after A. N. Tupolev, Kazan, 420111 Russia ^{2}Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow, 125412 Russia ^{3}Kazan Federal University, Kazan, 420008 Russia
Keywords: lowtemperature plasma, electric discharge, plasmaliquid systems, numerical methods
Abstract >>
The characteristics and mathematical modeling of the behavior of a lowtemperature direct current electric discharge plasma ignited between an aluminum anode and an electrolytic cathode (3% NaCl solution in purified water) at atmospheric pressure have been studied. The discharge is ignited by immersing the metal anode into the electrolytic cathode. The types and forms of plasma structures generated in the interelectrode gap are considered. The results of highspeed recording of the processes of breakdown and combustion of the discharge are presented. The electrophysical parameters of the discharge, including pulsations, current and voltage fluctuations, have been studied. The emission spectroscopy method was used to determine the discharge radiation spectrum, plasma composition, electron concentration, and temperature of heavy plasma components. The thermograms of the surface of liquid nonmetallic and metallic electrodes in the discharge burning zone are considered. The results of numerical simulation of the electric field strength and the initial stage of the discharge are presented.

E. A. Baranov^{1}, A. O. Zamchii^{1,2}, N. A. Lunev^{1,2}, I. E. Merkulova^{1}, V. A. Volodin^{3,4}, M. R. Sharafutdinov^{5}, A. A. Shapovalova^{6}
^{1}Kutateladze Institute of Thermal Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia ^{2}Novosibirsk State University ^{3}Novosibirsk State University, Novosibirsk, 630090, Russia ^{4}Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia ^{5}Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia ^{6}Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
Keywords: nanocrystalline silicon, nonstoichiometric silicon oxide, thin film synthesis
Abstract >>
Thin films of amorphous nonstoichiometric silicon oxide (aSiO_{x}:H, 0 < x < 2) have been synthesized by gasjet deposition with activation by an electronbeam plasma. The stoichiometric coefficient of the aSiO_{x}:H films was varied in the range 0.471.63 depending on the parameter R determined by the mixture flow rate ArSiH4. Hightemperature (at a temperature of 950°C for 2 h) annealing of aSiO_{x}:H thin films led to the formation of 8.312.3 nm crystalline silicon nanoparticles. It is shown that with an increase in the parameter R, the degree of crystallinity of the annealed films increases up to 66%. It has been suggested that the position of the peak of nanocrystalline silicon in the Raman spectra is affected by mechanical stresses. As a result of a quantitative assessment of such a stress, the values of 1.01.7 GPa are obtained.

N. Zhou^{1,2,3}, D. Liu^{1}, Q. Nian^{4}, K. Tang^{1}, J. Wang^{1}, Yu. Fang^{3}
^{1}Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China ^{2}Nanjing Forest Police College, Nanjing 210023, Jiangsu, China ^{3}Anhui Honlly Clad Metal Materials Technology Co., Ltd, Xuancheng 242000, Anhui, China ^{4}China Railway Ten Bureau Group Third Construction Co. Ltd, Hefei 230601, Anhui, China
Keywords: impact dynamics, welding, plate, incident angle, protective performance, failure mode
Abstract >>
The protective performance of a threelayer explosive welded composite plate consisting of steel and aluminum plates is studied in ballistic experiments and numerical simulations. The mechanism of target plate failure under the impact of spherical fragments is investigated.

I. G. Donskoi
Melentiev Energy Systems Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk, 664033, Russia
Keywords: variational methods, equations of reactiondiffusionconvection, thermal explosion, reaction waves
Abstract >>
Variational formulations are proposed for the equations describing the stationary states of nonisothermal onedimensional reactors, including those under convective transfer. For the proposed variational formulations, several variants of the numerical solution are considered (based on the method of local variations and the RayleighRitz method). The features of the use of numerical methods in solving the considered problems are discussed: convergence, the ratio of the spatial grid step to the degree of the approximating polynomial. Modifications of the problem of thermal ignition are considered taking into account convective transfer and heat losses. A variational principle is proposed that determines the structure of the combustion front at a given propagation velocity. It is shown that this variational principle can be used along with the principle of minimum entropy production for a complete solution of the problem of stationary propagation of an exothermic reaction wave.

A. Mehmood^{1}, G. D. Tabassum^{1}, M. Usman^{2}, A. Dar^{3}
^{1}International Islamic University, Islamabad, 44000, Pakistan ^{2}Virtual University of Pakistan, Lahore, Pakistan ^{3}University of Kotli, Kotli, Azad Jammu and Kashmir, Pakistan
Keywords: Shrinking disk, unsteady flow, nonuniqueness, numerical solution
Abstract >>
Results of studying the problem of an unsteady fluid flow along an instantaneously stretching (shrinking) nonrotating disk with an infinite radius are reported. The velocity of the shrinking disk surface is chosen in such a way that the problem allows the existence of an exact similarity solution. The original problem is reduced to an initialvalue problem, which is solved numerically by using the shooting and NewtonRaphson methods. A detailed study of the existence and uniqueness of the solution is performed.

A. AlHanaya^{1}, Shreen ElSapa^{2}, E. A. Ashmawy^{2}
^{1}Princess Nourah bint Abdulrahman University, Riyadh, 11671, Saudi Arabia ^{2}Alexandria University, Alexandria, Egypt
Keywords: couple stress fluids, rotational motion, eccentric spheres, torque, collocation method
Abstract >>
This study deals with axisymmetric steady rotational movement of an incompressible couple stress fluid between two nonconcentric objects. Two spherical boundaries are revolving axially with different angular velocities. At low Reynolds numbers, the solution is obtained semianalytically utilizing the superposition guideline and the collocation approach. The hydrodynamic couple exerted by the fluid on the internal particle is considered. The results obtained in the study are compared with the corresponding results of the classical viscous fluids available in the literature.

A. A. Bazanov^{1}, B. E. Grinevich^{1}, A. B. Ivanovskii^{1,2}
^{1}AllRussian Research Institute of Experimental Physics, Sarov, 607188, Russia ^{2}Sarov Institute of Physics and Technology, Sarov, 607189, Russia
Keywords: capacitor unit, shock and shockless compression of materials, discharge current, liner velocity, electrocontact measurement technique, liner flight base
Abstract >>
Experiments on acceleration of flat metal liners by a magnetic field were performed on the Kaskad capacitor facility. Data on the asymmetry of the flight of liners both along the streamline and in the transverse direction are presented.

A. E. Golikov, N. I. Makarenko
Lavrent'ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
Keywords: free boundary, circular cylinder, hydrodynamic loads
Abstract >>
The accelerated motion of a circular cylinder from the state of rest under the free surface of an infinitely deep ideal fluid is studied using the method of reducing the original mathematical formulation of the problem to an integrodifferential system of equations for the function specifying the free surface shape and for the normal and tangential velocity components on the free surface. An analytic continuation of the velocity field into the flow region is constructed and unsteady loads acting on the cylinder at the initial stage of motion are determined.

S. M. Bazov^{1}, I. N. Zavialov^{1}, A. V. Konyukhov^{1,2}
^{1}Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russia ^{2}Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow, 125412, Russia
Keywords: selfoscillating mode, porosity medium, acidizing, double porosity, numerical investigation
Abstract >>
The transition of a filtration reactive flow in a double porosity medium into a selfoscillating mode is studied. Flow stability is analyzed using numerical methods for solving multiphase filtration equations in a medium with double porosity. The region of development of selfoscillations is investigated depending on the external parameters of the system and the properties of the reagents.

V. N. Grebenev^{1}, A. G. Demenkov^{2,3}, G. G. Chernykh^{1}
^{1}Federal Research Center for Information and Computational Technologies, Novosibirsk, 630090, Russia ^{2}Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia ^{3}Novosibirsk State Technical University, Novosibirsk, 630073, Russia
Keywords: method of differential constraints, threeparameter model of the turbulent wake, local equilibrium approximation, turbulent wake behind the body of revolution, numerical simulation
Abstract >>
The flow in the far turbulent wake behind a body of revolution is studied with the use of a threeparameter turbulence model, which includes differential equations of the turbulent energy balance, transport equation for the turbulent energy dissipation rate, and turbulent shear stress equation. Local equilibrium algebraic truncation of the transport equation for the turbulent shear stress yields the known KolmogorovPrandtl equation. Under a certain constraint on the values of the empirical constants and for the law of time scale growth consistent with the mathematical model, this equation is a differential constraint of the model or an invariant manifold in the phase space of the corresponding dynamic system. The equivalence of the local equilibrium approximation and the condition of the zero value of the Poisson bracket for the normalized turbulent diffusion coefficient and defect of the longitudinal component of velocity is demonstrated. Results of numerical experiments are reported; they are found to be in good agreement with theoretical predictions.

A. R. Bakhtybekova^{1}, N. K. Tanasheva^{1}, L. L. Minkov^{2}, N. N. Shuyushbaeva^{3}, A. N. Dyusembaeva^{1}
^{1}Buketov Karaganda University, Karaganda, 100026, Kazakhstan ^{2}National Research Tomsk State University, Tomsk, 634050, Russia ^{3}Ualikhanov Kokshetau University, Kokshetau, 020000, Kazakhstan
Keywords: wind turbine, deflector, cylinder, Magnus effect, modeling
Abstract >>
Numerical and experimental methods are used to investigate the aerodynamic characteristics of a laboratory sample in the form of a cylinder with an active rotating element  a deflectorthat can be used as a working power blade element of awind power plant. Numerical simulation was performed using the Ansys Fluent software based on the Reynoldsaveraged NavierStokes equations supplemented by a realizable (κε)turbulence model. Based on the results of numerical simulation, a laboratory model with a cylinder 205 mm long and 50 mm in diameter and a deflector 100 mm in diameter was made for experimental studies. A comparative analysis of the numerical and experimental aerodynamic characteristics of the model was carried out and the aerodynamic features of the airflow around the test sample were identified.

L. Kh. Ingel'^{1,2}
^{1}Research and Production Association "Taifun", Obninsk, 249038 Russia ^{2}A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, 119017, Russia
Keywords: slope currents, thermal inhomogeneities, density currents, linear perturbations, analytical model
Abstract >>
A twodimensional stationary linear model of flows arising in a stably (neutral) stratified medium over a thermally inhomogeneous flat inclined surface is analyzed analytically. At the lower boundary, temperature deviations are specified, which depend harmonically on the horizontal coordinate transverse to the slope. Explicit analytical solutions are obtained, which make it possible to analyze the regularities of emerging density flows. It is shown that these flows can qualitatively differ depending on the ratio of the slope angle of the lower boundary and the analog of the Rayleigh number, the expression for which includes the horizontal scale of the thermal inhomogeneity region as a spatial scale. An appropriate criterion for distinguishing these currents is established.

L. F. Sitdikova, I. K. Gimaltdinov
Ufa State Oil Technical University, Ufa, 450064, Russia
Keywords: sound wave, porous medium, reflection coefficient, transmission coefficient
Abstract >>
The reflection and transmission of harmonic waves is theoretically investigated at the interface between a bubbly liquid and a porous medium saturated with this liquid has been studied theoretically. The influence of the parameters of the system on the coefficients of reflection and transmission through the interface between the two media has been investigated. It has been found that for the interface between the bubbly liquid and the porous medium saturated with the bubbly liquid, there is a range of frequencies in which reflection occurs in the same way as from a free surface and the back reflection as from a rigid wall.

V. Rizov^{1}, H. Altenbach^{2}
^{1}University of Architecture, Civil Engineering and Geodesy, Sofia, 1046, Bulgaria ^{2}OttovonGuerickeUniversitat Magdeburg, Magdeburg, 39106, Deutschland
Keywords: multilayered beam, inhomogeneous material, nonlinear creep, delamination
Abstract >>
This paper is focused on deriving a common solution to the strain energy release rate for delamination cracks in multilayered inhomogeneous beams under nonlinear creep. The layers of the beams exhibit material inhomogeneity in the thickness direction. The solution is obtained for the nonlinear stressstraintime relation. The J integral approach is applied to verify the solution. The variation of the strain energy release rate with time as a result of the nonlinear creep behaviour is analyzed.

S. D. Algazin^{1}, I. A. Selivanov^{2}
^{1}Ishlinsky Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow, 119526, Russia ^{2}Lomonosov Moscow State University, Moscow, 119991, Russia
Keywords: numerical methods without saturation, plate flutter, flutter critical velocity, analytical dependence
Abstract >>
The paper considers the solution of the plate flutter problem with mixed boundary conditions. The mathematical formulation of the problem allows taking into account arbitrary directions of the incoming flow vector. For the numerical solution of the problem, a modern numerical algorithm without saturation is proposed, which allows obtaining the critical flutter speed with sufficient accuracy on a sparse grid. The results of calculations for four materials are presented: titanium, steel, aluminum, duralumin. Based on the calculation results, two analytical dependences for the critical flutter speed are obtained: from the direction of the incoming flow vector, as well as from the dimensionless speed of sound in the plate and the thickness of the plate. The eigenforms Re(φ) corresponding to the critical flutter speed are given.

M. Babanly, R. Mekhtiyev, N. Gurbanov, D. Aslanov, Yu. Tanriverdiev
Azerbaijan State University of Oil and Industry, Baku, AZ1010, Azerbaijan
Keywords: elliptical crack, hybrid nanocomposite, tension, plasticity
Abstract >>
A technology for obtaining hybrid nanocomposite materials with a 7075T6 aluminum matrix and a filler in the form nanoparticles is proposed. A review of experimental data and computer and theoretical models of crack initiation processes is presented. The mechanisms of microcrack nucleation under uniaxial tensile load are determined. To study the fracture of loaded nanocrystalline materials and determine their mechanisms, a model is proposed that describes the formation and growth of nanocracks near the tips of elliptical cracks in a hybrid nanocomposite material. The dependences between the applied force and the crack length are obtained using the parameters of a modeled crack.

V. M. Kulik
Kutateladze Institute of Thermal Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
Keywords: silicone rubber, singlewalled carbon nanotubes, elastic modulus, loss factor
Abstract >>
A study was made of the change in the dynamic viscoelastic properties of silicone rubber with the addition of a small fraction (0.05; 0.10%) of singlewalled carbon nanotubes. In the region of linear deformation, the elastic modulus and loss factor were measured. It has been established that the addition of nanotubes and the aging of materials lead to an increase in the elastic modulus, and the loss factor can either increase or decrease.

I. A. Bashchikova
Lavrentyev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
Keywords: torsion, rod, deformation of the cross section, kinematic modes, creep, inverse problem
Abstract >>
Problems are considered that describe the process of obtaining the residual angle of twist of a rod under creep conditions, taking into account elastic recovery after unloading. It is assumed that a constant linear angle of twist is set for the section being formed, i.e., the section is in conditions of pure torsion, without constraining the ends of the rod. It is believed that strains and stresses depend only on time and two spatial coordinates in the plane of the cross section of the rod. Direct and inverse problems of torsion of a rod with rectangular and angular cross sections in various kinematic creep regimes are considered. The speed of the angle of twist during the entire deformation process is set constant. A method of numerical calculation based on the finite element method is proposed, which makes it possible to obtain the stiffness characteristics of the section under torsion in the case of creep. It is shown that the minimum level of residual stresses is observed in the relaxation mode of deformation. For a rod with a crosssection of the angular type, modes are found in which stresses significantly decrease in the area of their concentration.

M. Mohammadi^{1}, M. Nazari^{1}, M. H. Kayhani^{1}, G. Ahmadi^{2}
^{1}Shahrood University of Technology, Shahrood, Iran ^{2}Clarkson University, Potsdam, NY 136995725, USA
Keywords: Particlebubble collision, sliding velocity, modified Bond number, threephase contact line
Abstract >>
In the present study, an experimental approach is developed to study collisions of particles with a fixed air bubble. An air bubble with a diameter of 5.5 mm in deionized water is created, plastic particles (with diameters of 1.5, 2, and 2.5 mm) are released at different heights from the bubble surface, and their collisions with the bubble surface are studied. The results show that the particle size significantly affects the particle velocity and sliding time on the bubble surface. As the particle diameter increases, its sliding velocity on the bubble surface increases, and the particles are detached quickly from the bubble surface. The effects of the drag, capillary, pressure, weight, and buoyancy forces acting on the particles during the attachmentdetachment on the bubble surface are also studied. The results show that the particle stays attached if the capillary force is dominant. The effects of the threephase contact line on the capillary and pressure forces are also analyzed. A modified Bond number is proposed to check the attachmentdetachment regimes.

