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Three-Dimensional Convection in an Inclined Porous Layer Subjected to a Vertical Temperature Gradient

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Fluid Dynamics & Materials Processing 2024年第9期20卷 1957-1970页

作者： Ivan Shubenkov tatyana lyubimova Evgeny Sadilov Computational Fluid Dynamics Laboratory Institute of Continuous Media Mechanics UB RASPerm614068Russia Theoretical Physics Department Perm State UniversityPerm614990Russia

In this paper,we study the onset and development of three-dimensional convection in a tilted porous layer saturated with a *** layer is subjected to a gravitational field and a strictly vertical temperature ***,problems of thermal convection in tilted porous media saturated with a liquid are studied by assuming constant different temperatures at the boundaries of the layer,which prevent these systems from supporting conductive(non-convective)*** boundary conditions considered in the present work allow a conductive state and are representative of typical geological *** an earlier work,we carried out a linear stability analysis of the conductive *** was shown that at any layer tilt angles,the most dangerous type of disturbances are longitudinal ***,a non-zero velocity component exists in *** the present work,threedimensional non-linear convection regimes are *** original three-dimensional problem is reduced to two-dimensional one with an analytical expression for the velocity z-component v_(z)=v_(z)(x,y).It is shown that the critical Rayleigh number values obtained through numerical solutions of the obtained 2D problem by a finite difference method for different layer inclination angles,are in a good agreement with those predicted by the linear *** number of convective rolls realized in nonlinear calculations also fits the linear theory predictions for a given cavity *** carried out at low supercriticalities show that a direct bifurcation takes *** increasing supercriticality,no transitions to other convective regimes are *** situation studied in this problem can be observed in oil-bearing rock formations under the influence of a geothermal temperature gradient,where the ensuing fluid convection can affect the distribution of oil throughout the layer.

关键词： Thermal convection inclined layer porous media vertical temperature gradient

A Numerical Investigation of the Effect of Boundary Conditions on Acoustic Pressure Distribution in a Sonochemical Reactor Chamber

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1425-1439页

作者： Ivan Sboev tatyana lyubimova Konstantin Rybkin Michael Kuchinskiy UEC-Aviadvigatel 93 Komsomolsky ProspectPerm614990Russia Laboratory of Computing Hydrodynamic Institute of Continuous Media Mechanics UB RASPerm614013Russia Laboratory of Interfacial Hydrodynamic Perm State UniversityPerm614068Russia

The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis,extraction and *** of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the *** has a strong impact on the surface degradation *** this work,a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL *** numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions for various thicknesses of the piezoelectric *** particular,the amplitude of the acoustic pressure is minimal in the case of absorbing boundaries,and the attenuation becomes more significant as the thickness of the piezoelectric transducer *** addition,reflective boundaries play a significant role in the formation and distribution of zones of maximum cavitation activity.

关键词： Ultrasound numerical simulation acoustic pressure field cavitation erosion foil test

Formation of Water Quality of Surface Water Bodies Used in the Material Processing

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Fluid Dynamics & Materials Processing 2024年第4期20卷 815-828页

作者： tatyana lyubimova Anatoly Lepikhin Yanina Parshakova Irina Zayakina Alibek Issakhov Laboratory of Computational Fluid Dynamics Laboratory Institute of Continuous Media Mechanics UB RASPerm614068Russia Laboratory of Land Hydrology Problems Mining Institute UB RASPerm614000Russia Department of Theoretical Physics Perm State UniversityPerm614990Russia Department of Mathematical and Computer Modeling Al-Farabi Kazakh National UniversityAlmaty050040Republic of Kazakhstan

In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required *** in many regions of the world,there is an acute problem of providing industry with water of a required *** solution is an urgent and difficult *** water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors,and is often significantly heterogeneous not only in the water area,but also in *** a rule,the water supply of large industrial enterprises is located along the river *** are the most important nodes of river *** the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water *** recent years,thanks to the data of satellite images,the interest of researchers in the phenomenon of mixing the waters of merging rivers has *** nature of the merger is influenced by the formation of transverse *** the framework of this work,a study of vorticity,as well as the width of the mixing zone,depending on the distance from the confluence,the speeds of the merging rivers and the angle of confluence was carried *** the consumer properties of water are largely determined by its chemical and physical indicators,the intensity of mixing,determined largely by the nature of the secondary circulation,is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing *** characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties,but also for organizing an effective monitoring system for confluence zones.

关键词： Water for material processing water quality formation of transverse circulation

Investigation of Cavitation in NaCl Solutions in a Sonochemical Reactor Using the Foil Test Method

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1093-1102页

作者： Michael Kuchinskiy tatyana lyubimova Konstantin Rybkin Anastasiia Sadovnikova Vasiliy Galishevskiy Institute of Continuous Media Mechanics UB RAS Perm614013Russia Faculty of Physics Perm State UniversityPerm614068Russia

Ultrasonic baths and sonochemical reactors are widely used in industrial applications dealing with surface cleaningand chemical synthesis. The processes of erosion, cleaning and structuring of the surface can be typically controlledby changing relevant influential parameters. In particular, in this work, we experimentally investigate theeffect of NaCl concentration (0–5.5 mol/L) on the erosion of an aluminum foil under ultrasonic exposure at afrequency of 28 kHz. Special attention is paid to the determination of cavitation zones and their visualizationusing heat maps. It is found that at low NaCl concentration (0.3 mol/L), the foil destruction rate is higher thanin distilled water. At higher concentrations of salt, cavitation takes place mainly in the upper part of the container.

关键词： Ultrasound NaCl solution foil test cavitation activity

A Method Based on Thermo-Vibrational Effects for Hydrogen Transportation and Storage

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Fluid Dynamics & Materials Processing 2024年第12期20卷 2775-2788页

作者： tatyana P.lyubimova Sergey A.Plotnikov Albert N.Sharifulin Vladimir Ya.Modorskii S.Neshev Stanislav L.Kalyulin Institute of Continuous Media Mechanics Ural Branch of Russian Academy of SciencesPerm614013Russia Aerospace Faculty Perm National Research Polytechnic UniversityPerm614990Russia

Transporting and storing hydrogen is a complex technological task.A typical problem relates to the need to minimize the strength of fluid motion and heat transfer near the walls of the *** this work this problem is tackled numerically assuming an infinite cavity of pipe square cross-section,located in a constant external temperature *** particular,a method based on the application of vibrations to suppress the gravitational convection mechanism is explored.A parametric investigation is conducted and the limits of applicability of the method for small Grashof numbers(10e4)are *** is shown that it is possible to minimize the intensity of the vibrogravitational flow for any values of the problem parameters if correction factors are *** results obtained can be applied in technological processes associated with the transportation,storage and use of hydrogen:pumping the working fluid through pipes,storage in tanks,as well as flow processes in the combustion chambers of power plants.

关键词： Thermal vibration convection vibrations vortex structures square pipe cavity hydrogen transportation and storage