Multiphase Systems最新文献

{"title":"The algorithm for determining the pulling force while dragging a pipeline","authors":"I. N Krioni, A. Semenova, V. Kireev","doi":"10.21662/MFS2018.3.005","DOIUrl":"https://doi.org/10.21662/MFS2018.3.005","url":null,"abstract":"This article describes the process of dragging a pipeline through a channel. In the simulation of this process, the interactions between the pipeline, the drill rod, the soil and the bentonite mud are taken into account. Dragging of the pipeline through the well is hampered by frictional forces of the pipeline and the drill rod against the soil, as well as the drag force of the pipeline when it moves in the drilling fluid. In the construction of a mathematical model, the influence of these forces is taken into account. To determine the frictional forces, the pipeline and the drill rod were considered as a flexible non-stretch filament. An algorithm for determining the tractive effort is created and implemented. A separate stage of the work is devoted to the accounting of ballasting of the pipeline.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115383223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of research solid mechanics laboratory for 2020–2022","authors":"M. M. Shakir’yanov","doi":"10.21662/mfs2022.1.006","DOIUrl":"https://doi.org/10.21662/mfs2022.1.006","url":null,"abstract":"The article presents an overview of the research of the Laboratory of Solid Mechanics IMech UFRS RAS for 2020-2022. All studies were published as articles (there are two exceptions in the list of references, registered in the Register of Computer Programs) in well-known domestic and (or) foreign scientific journals on mechanics. During the three years under consideration, a number of new problems of aerohydroelasticity were solved and important results were obtained on the dynamic behavior of thin-walled structural elements interacting with external and internal continuous media. In particular, the linear bending of a cantilever rod loaded with all-round pressure and longitudinal force is considered in static and dynamic formulations. The areas of attraction of the deflection to the upper and lower equilibrium positions of a two-support pipe during its spatial bending-rotational vibrations are determined. The interaction of forced and parametric vibrations of the pipeline has been studied. The influence of the internal and external added masses of continuous media on the frequency of natural vibrations of a pipe moving with acceleration in the transverse direction is studied. The eigenfrequencies of bending vibrations of a micro- and nanometer-sized rod clamped at the ends are calculated. From the solution of the inverse problem for the changed values of natural frequencies, the coordinate and magnitude of the added mass are found. Linear oscillations of micro- and nanostrings are also considered when the pressure in a gaseous medium changes, taking into account surface effects. Using a model of molecular dynamics with a reduced number of degrees of freedom, the eigenfrequencies of bending vibrations of carbon nanotubes (CNTs) of different diameters are calculated under conditions of a plane-deformed state. In addition, part of the work was devoted to the study of the phenomenon of the ascent of an underwater gas pipeline and the determination of its buoyancy parameters. The scientific articles presented in this review are arranged in chronological order. For all articles, their summary is given and the main conclusions are formulated.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117030515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Jumping drops on the surface of the water","authors":"A. Terentiev","doi":"10.21662/mfs2020.3.135","DOIUrl":"https://doi.org/10.21662/mfs2020.3.135","url":null,"abstract":"The paper proposes a theoretical model for the bouncing of a water drop on a free surface. The motion of a drop in air is described by the usual equations connecting the forces of inertia, gravity, and Stokes (viscosity resistance). The drop is considered spherical with a given surface tension. Numerical calculations were carried out using the same algorithm, but with different initial conditions. Some conditions are set for the droplet disintegration, others for the droplet reflection from the free surface. It is shown that the disintegration of a drop occurs periodically with a decrease in the drop size and an increase in the drop rise height. In the interval between droplet decays, periodic reflection from the free surface occurs with a decrease in the rise height.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123963135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical study of velocity slip of phases during the passage of a shock wave of low intensity from a pure gas to a dusty medium","authors":"D. A. Tukmakov","doi":"10.21662/mfs2019.2.017","DOIUrl":"https://doi.org/10.21662/mfs2019.2.017","url":null,"abstract":"In this paper, the process of the movement of a direct shock wave from a pure gas into a dusty medium is numerically modeled. The mathematical model took into account the viscosity, compressibility and thermal conductivity of the carrier phase. Also, the modeling technique made it possible to describe the interphase force interaction, which included the Stokes force, the dynamic force of Archimedes, the strength of the attached masses. In addition, interfacial interaction included heat transfer between the carrier and dispersed phases. The numerical solution was carried out using the explicit finite-difference method, with the subsequent application of the nonlinear correction scheme for the grid function. As a result of numerical calculations, it was revealed that with an increase in the linear particle size of the gas suspension, the velocity slip between the carrier and dispersed phases increases. Numerical modeling also showed that the absolute value of the difference between the velocities of the carrier and the dispersed phase reaches the largest value at the leading edge of the compression wave. The revealed regularities can be explained by the fact that the particles of the dispersed phase are assumed to be spherical in shape. Due to this, a multiple increase in particle size leads to a three-fold increase in their mass, a twofold increase in the area of one particle and a three-fold decrease in the number of particles. Thus, an increase in particle size leads to a decrease in the area of interfacial contact and an increase in the inertia of the particles, which in turn affects the interfacial velocity slip.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131458235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermocapillary migration of droplets and bubbles in a viscous liquid (review)","authors":"E. Nasibullaeva, S. Urmancheev","doi":"10.21662/mfs2020.3.125","DOIUrl":"https://doi.org/10.21662/mfs2020.3.125","url":null,"abstract":"Investigation of the process of accumulation of gas bubbles in the aria of a heat source is, from a physical point of view, quite interesting problem that leads to important conclusions for practical applications. The peculiarity of the process under consideration is that the surface tension of the bubble changes in an alternating temperature field, which, in turn, leads to the appearance of a flow in the boundary layer of the liquid. In the world scientific literature, the discovery and description of the effect of gas bubble migration in the direction of the temperature gradient is usually associated with the experimental work of Yang, Goldstein and Block (1959). Without diminishing its significance, we note that the effect was first predicted in the theoretical work of Fedosov (1956) as a result of solving the problem of the onset of a microflow of a liquid near plane and spherical interphase boundaries in the presence of a temperature gradient. In both works, a significant factor in explaining the described phenomenon was the dependence of surface tension on temperature. After some time, after which it was realized the need to take into account the migration of not only bubbles, but also droplets, in inhomogeneous temperature fields in space technologies, biomedical and other applications, there was a significant number of publications on this subject, and this phenomenon was called thermocapillary migration. This review is devoted to the analysis of the main, in the opinion of the authors of the article, results of experimental, theoretical and applied research to establish the mechanism of migration bubbles and drops in temperature gradient fields. In most works, it is assumed that there is no dependence of the physical properties of a liquid, except for surface tension, on temperature. There are only a few studies where the influence of the temperature dependence of the viscosity coefficient was considered, which gives a new impetus to the continuation of research and the development of the theory of the effect, taking into account the thermorheological properties of working media.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131807045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of the speed and density of the fluid inside the pipeline on elastic supports","authors":"A. A. Yulmukhametov, A. G. Khakimov","doi":"10.21662/mfs2019.4.033","DOIUrl":"https://doi.org/10.21662/mfs2019.4.033","url":null,"abstract":"The natural frequencies of the bending vibrations of the pipeline are investigated. The pipe sags over the obstacle and is under the action of tensile force. Outside the sagging area, the pipe rests on elastic supports. The fluid transported through the pipeline is under pressure. The direct problem was solved earlier, in this article, the inverse problem of identifying the speed and density of the transported fluid by the known natural frequencies of bending vibrations is solved. The equation of bending vibrations of a pipeline is described by the Kirchhoff model. The characteristic equation is solved using Ferrari formulas. The general decision is determined. We substitute the general solution into the boundary conditions and obtain a system of equations. This system gives a frequency equation, which is solved numerically on a developed program in the Maple package. The method of successive approximations is applied, after the third iteration, the accuracy of calculating the parameters of the velocity and density of the liquid is approximately 10−3. Thus, it was found that with an increase in the oscillation frequency, the density of the liquid inside the pipe decreases. It is determined that with increasing natural frequencies of pipe bending vibrations, the fluid velocity parameter increases. It is shown that the two lower frequencies of bending vibrations of the pipeline can be used to determine the parameters of the velocity and density of the liquid. The dependence of the mass flow rate of the liquid on the first natural frequency of the pipe oscillations is given. It is shown that with increasing frequency, the mass flow rate decreases. The research results will help the development of acoustic diagnostic methods and non-destructive testing methods and will find technical application for monitoring and diagnosing the state of pipeline systems.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"409 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115922228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of diffusion on the acoustic properties of a bubble fluid","authors":"U. O. Agisheva, I. I. Vdovenko, M. Galimzyanov","doi":"10.21662/mfs2019.3.023","DOIUrl":"https://doi.org/10.21662/mfs2019.3.023","url":null,"abstract":"The problems of wave propagation in bubble media have been of great interest to researchers for almost half a century in connection with the wide distribution of these systems in nature and their intensive use in modern technologies. It is known from the literature that the intensity of attenuation of sound disturbances in the gas-liquid media under consideration is mainly determined by the thermophysical characteristics of the gas in the bubbles. It turns out that these effects are significantly enhanced with increasing vapor concentration due to an increase in the temperature of the system. There are a large number of publications in the literature in which various statements of the wave action on bubble media have been considered. In the present work, the propagation of small perturbations in a liquid with bubbles filled with vapor and a gas insoluble in the liquid phase is considered in the plane one-dimensional and single-velocity approximations. The rate of liquid evaporation (condensation) inside the bubble was determined from the condition of heat balance. To take into account interphase heat and mass transfer, the heat conduction and diffusion equations inside the bubble and the heat conduction equation in the fluid around the bubble are used. From the condition for the existence of a solution in the form of a decaying traveling wave, taking into account the effects of acoustic unloading of bubbles, the dispersion equation is written. From the condition for the existence of a solution in the form of a decaying traveling wave, taking into account the effects of acoustic unloading of bubbles, the dispersion equation is written. Based on the obtained dispersion equation, relations are written for the equilibrium speed of sound depending on the thermophysical parameters of the medium and numerical calculations are performed for water with vapor-gas bubbles. The features of the reflection of harmonic waves from the interface between the “pure” liquid and liquid with vapor-gas bubbles are studied. The influence of the perturbation frequency and the temperature of the medium on the attenuation coefficient of the acoustic wave is studied. The influence of diffusion on the evolution of harmonic waves is analyzed.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128731483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the influence of boundary conditions in the numerical solution of a vortex tube model","authors":"M. R. Minibaev, C. Mikhaylenko","doi":"10.21662/mfs2019.2.013","DOIUrl":"https://doi.org/10.21662/mfs2019.2.013","url":null,"abstract":"The applicability of various boundary conditions in the computational simulation of a Ranque–Hilsch vortex tube is investigated. A review of existing works on the effect of geometry and various thermodynamic parameters on the efficiency of the pipe is made. The substantiation of the possibility of introducing additional computational domains when moving the boundaries to study the influence of boundary conditions when modeling gas dynamics problems is given. To simulate the dynamics of a gas in a vortex tube, a mathematical model is written that includes the Navier–Stokes system of equations describing a compressible viscous fluid, which is closed by the equation of state of an ideal gas. Existing methods for calculating turbulent flows are considered. The applicability of various semi-empirical models of turbulence for modeling a vortex tube is described. The possibility of using the selected k−ε model and its description is argued. The boundary conditions characteristic of the vortex tube model are described, and the boundary conditions most combined in the simulation of gas dynamics problems are also shown. Presents a grid that takes into account the area formed by the removal of boundaries. The solution is based on the sonicFoam algorithm in the OpenFOAM package. Utilities of the postprocessor are used when preparing the model for calculations on a high-performance cluster and utilities for averaging the obtained physical quantities. The simulation results for different combinations of boundary conditions and models with remote boundaries are given. Comparison of the results obtained. It is shown that the geometrical dimensions have a strong influence on the operation of the pipe; the correct choice of boundary conditions makes it possible to obtain the values of physical quantities that are closest to the known experimental ones. Moving the boundaries away from direct exits provides an opportunity to more accurately estimate the effects that arise near the real boundaries of the vortex tube, especially affecting the magnitude of the Ranque–Hilsch effect.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115304487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of dislocations in the domain structure of the nematic liquid crystal","authors":"V. Delev","doi":"10.21662/mfs2020.3.130","DOIUrl":"https://doi.org/10.21662/mfs2020.3.130","url":null,"abstract":"Dynamics and interaction of classical dislocations in the domain structure of π/2 nematic liquid crystal is studied. A feature of twisted nematics is that hydrodynamic flows in Williams domains, together with the tangential component of velocity, also have an axial component, the direction of which is opposite in neighboring domains. Dislocations can move both perpendicular (glide) to Williams domains, and along (climb) them. It was found that when dislocations collide with opposite topological charges S = ±1 at given voltage, their speed increases. It has been shown that dynamics and interaction of dislocations with topological charges S = ±1 are qualitatively well described by the perturbed sine-Gordon equation.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122923679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shock wave reflection from a layer of a finely dispersed medium with low concentrations","authors":"K. Bashirova, C. Mikhaylenko","doi":"10.21662/mfs2019.4.036","DOIUrl":"https://doi.org/10.21662/mfs2019.4.036","url":null,"abstract":"The paper investigates the propagation of a shock wave when interacting with a loosely packed granular medium. The continuous two-phase mathematical model presented in this work allows one to numerically describe the propagation of a shock wave in the channel of a shock tube, the achievement of a layer of granular filling by the shock wave, and the reflection of the wave. It was shown that the granular medium partially transmits the shock wave, but mostly corresponds to it. This reflection differs from the reflection of a shock wave from a solid wall. The nature of the reflection of the shock wave depends on the density of the granules. In particular, it has been shown that a granular medium of lower density, due to the increased mobility of individual particles, leads to some amplification of the reflected wave. It is also shown that the reflected wave in this case forms two pronounced peaks. It should be noted that the pressure passed in the layer of the granular medium, on the contrary, turns out to be the greater, the heavier the particles of the granular medium.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134645673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}