Multiphase Systems最新文献_第5页

The formation features of supercritical steam-water jets (review) 超临界蒸汽-水射流的形成特征(综述)

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2022.1.003

R. Bolotnova, V. Korobchinskaya

{"title":"The formation features of supercritical steam-water jets (review)","authors":"R. Bolotnova, V. Korobchinskaya","doi":"10.21662/mfs2022.1.003","DOIUrl":"https://doi.org/10.21662/mfs2022.1.003","url":null,"abstract":"The review of works on study of dynamics formation of water fluid jet of supercritical parameters outflowing from a high-pressure chamber through a thin nozzle has been carried out. The system of model equations describing the dynamics of outflow processes in both single-phase and multiphase gas-vapor-liquid media is considered. It based on the laws of conservation of mass, momentum and energy of phases in accordance with single-pressure, single-speed and two-temperature approximations with the allowance for contact-type heat transfer and mass transfer for evaporation and condensation under equilibrium conditions. The numerical realization of model representations is carried out by the method of movable Lagrangian grids and using modified solvers of the OpenFOAM package. The analysis of the features initial stage of the formation of a steam-water jet at outflow through a thin nozzle is given based on the results of numerical simulation by the Lagrangian method in the case of a two-dimensional axisymmetric formulation. The problems about the study of the evolution a forming jet during the outflow of a single-phase flow of water-steam and a boiling jet of supercritical state parameters are considered, by the numerical realization in the OpenFOAM package. The features the formation of Mach disk, accompanied by the appearance of a cavity inside the jet, are noted. It is shown that during the outflow of a boiling steam-water jet, the vortex zones are formed near the axis of symmetry and periodic pulsations of pressure and mass velocity are generated, which subsequently lead to acoustic oscillations preceding the main jet flow observed in experiments. The justification of reliability the applied numerical method realized by the new OpenFOAM solvers is given on the example of comparing numerical and analytical solutions to L.I. Sedov’s problem of a point explosion in two-phase gas-drop mixture and comparing the results of numerical solution and experimental photography of supersonic nitrogen jet outflowing through cylindrical nozzle from high-pressure vessel.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"34 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":"130433701","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}

引用次数: 0

Analysis of methane production intensity during its displacement from a gas hydrate formation by carbon dioxide 二氧化碳驱替天然气水合物过程中甲烷生产强度分析

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.3.021

M. Khasanov, G. R. Rafikova

{"title":"Analysis of methane production intensity during its displacement from a gas hydrate formation by carbon dioxide","authors":"M. Khasanov, G. R. Rafikova","doi":"10.21662/mfs2019.3.021","DOIUrl":"https://doi.org/10.21662/mfs2019.3.021","url":null,"abstract":"The theoretical model is considered in the one-dimensional approximations and numerical solutions are obtained for the process of replacing methane with carbon dioxide from a hydrate in a formation saturated with methane and its hydrate when carbon dioxide is injected into the formation. The process is considered under thermobaric conditions corresponding to the stability region of methane gas and carbon dioxide and the region of existence of CO2 in the form of a gaseous phase. The case is considered when the rate of carbon dioxide hydrate formation is limited by diffusion of carbon dioxide through the formed hydrate layer between the gas mixture stream and methane hydrate. It is accepted that the hydration substitution process occurs without the release of water from the hydrate. To describe the mathematical model, the main equations are the mass conservation equations for methane, carbon dioxide and their hydrates, Darcy’s law for filtration, Fick’s law for diffusive mixing of the gas mixture, state equations for the gas phase, Dalton’s law, energy equation, diffusion equation for transport CO2 through the hydration layer at the pore microchannel scale. The dynamics of the mass flow rates of the outgoing carbon dioxide and methane recovered has been investigated. The influence of the diffusion coefficient, the absolute permeability and the length of the formation on the intensity of the methane produced as a result of the gas substitution process is analyzed. Three main stages of the process were identified: displacement of free methane from the reservoir; extraction of free methane obtained as a result of the beginning of hydrate substitution in the formation; complete conversion of methane hydrate to carbon dioxide hydrate and complete extraction of methane from the formation. It is determined how the two main factors relate to each other in terms of the degree of influence on the replacement rate: heat and mass transfer in the reservoir and the kinetics of the replacement process.","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":"129539756","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}

引用次数: 0

Numerical simulation of acoustic scattering from coaxial sound-penetrable spheres 同轴透声球声散射的数值模拟

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.2.016

E. Nasibullaeva

{"title":"Numerical simulation of acoustic scattering from coaxial sound-penetrable spheres","authors":"E. Nasibullaeva","doi":"10.21662/mfs2019.2.016","DOIUrl":"https://doi.org/10.21662/mfs2019.2.016","url":null,"abstract":"This paper presents a generalisation of the mathematical model and numerical study of the acoustic scattering problem from multiple spheres in the case of spheres through which the wave passes and whose centers are located on the same axis (the case of sound-penetrable and coaxial spheres) under the action of spherical waves from a monopoly radiation source arbitrarily located in space. When solving the Helmholtz equations, a numerical technique based on the fast multipole method has been adapted for this task, which allows one to achieve high accuracy of the results obtained with minimal computer time. Comparison of the different approaches to truncation infinite series in the expansion showed the following: the result with a good degree of accuracy by a single calculation gives approach based on the truncation of all the rows with a fixed number in each expansion, and the result with a certain degree of accuracy gives an approach based on comparing two consecutive values of the sum of the series. A numerical parametric analysis of the pressure distribution inside and outside the spheres is carried out for various values of their radii, physical characteristics of the external and internal media, the number of spheres, the distances between the centers of the spheres, the frequency of exposure and the location of the monopole radiation source. It is shown that at certain values of the parameters, the appearance of zones of decrease or increase in pressure behind sound-penetrable spheres is possible. The obtained results will further allow to carry out test calculations to verify the general numerical algorithm for the case of a multitude of spheres arbitrarily located in space.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"46 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":"126206605","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}

引用次数: 0

Pressure waves in a tube filled with a liquid with a bubble region in it in the form of a torus 管内充满液体的压力波，管内有一个环面形状的气泡区域

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2021.3.015

M. Galimzyanov

引用次数: 0

Transfer by a Manipulator with a Three-finger Grasp of a Brittle Cylinder 用三指抓取脆性气缸的机械手进行转移

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.3.026

Y. Golubev, E. Melkumova

{"title":"Transfer by a Manipulator with a Three-finger Grasp of a Brittle Cylinder","authors":"Y. Golubev, E. Melkumova","doi":"10.21662/mfs2019.3.026","DOIUrl":"https://doi.org/10.21662/mfs2019.3.026","url":null,"abstract":"We consider the problem of the brittle cylinder grasping by the n fingers of the robot-manipulator. Each finger contacts the cylinder in a single supporting point with Amontons-Coulomb or for two footholds spinning friction. Using numerical simulations and analytically, possible locations of contact points on the cylinder, for which there is a kinetostatics problem solution when the cylinder is moved by three fingers, are received. By the analogy of the equilibrium of a three-legged robot on a cylinder for the problems of transfer by a manipulator with a three-finger grasp of a cylinder or for a robot on a surface which legs suspension points are on a cylinder surface. Two supporting points can be on one diameter in the cylinder base. Or because of friction on the opposite sides of the robot center of mass or giving in the dynamics, it is point C. The analogy of the problem is oscillations in the vicinity of the stable equilibrium one cylinder on another. The cylinder lies on one finger rectangular to it, of the hand of a hu-manoid robot, adheres to the end of the other finger. Similarly holds the glass. Robot can hold the horizontal cylinder by three fingers. Let one of the points is in vertical plane containing cylinder axis and another are in the plane orthogonal to the axis. The supporting points are on the external surface of the lower semi-cylinder and the cylinder center mass is in the footholds triangle. The supporting set is divided into two subsets.","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":"127838767","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}

引用次数: 1

Scattering of sound waves on spheres: methods and main characteristics (review) 声波在球体上的散射:方法和主要特征(综述)

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2021.3.013

E. Nasibullaeva

{"title":"Scattering of sound waves on spheres: methods and main characteristics (review)","authors":"E. Nasibullaeva","doi":"10.21662/mfs2021.3.013","DOIUrl":"https://doi.org/10.21662/mfs2021.3.013","url":null,"abstract":"The investigation of the sound wave scattering phenomenon on small-sized inhomogeneities is important both for studying the fundamental nature of this phenomenon and from a practical point of view, since many applications of acoustic waves are based on scattering phenomenon, such as sonar, sounding of the atmosphere and ocean, nondestructive testing devices, creation of a positioned 3D sound, etc. In many systems under consideration, obstacles are spherical (or can be considered as such). Present review is devoted to the analysis of the main works on theoretical methods for solving problems of acoustic wave scattering on spheres and determining the main characteristics of this phenomenon, as well as on existing experimental works. Two theoretical approaches to solving the presented problem can be distinguished. In the first approach, it is assumed that the distribution of scatterers is random, and the average value of the scattered field is calculated. In the second approach, which is given the main attention in this paper, the solution is reduced to large system of integral or linear algebraic equations using various methods, such as the T-matrix method, addition theorems for spherical functions, Green’s functions, integral equations. The first approach allows one to consider systems with a large number of randomly distributed particles, however, due to the averaging of the sound field, it is impossible to determine the pressure at a specific point in space. The second approach makes it possible to determine the zones of increasing and decreasing pressure, however, for a large number of spheres, the solution requires significant computing resources and processor time. The analysis of scientific papers that define the main characteristics of the scattering phenomenon, such as the total or back scattering cross-section, has shown that analytical formulas and numerical studies are limited to the cases of a single sphere or systems with two spheres. Thus the problem of determining the formulae for these characteristics in the general case remains unsolved and is relevant.","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":"115904026","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}

引用次数: 0

Comparison of the numerical and self-similar solutions of Sedov’s problem on a point explosion in gas 气体点爆炸Sedov问题数值解与自相似解的比较

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2020.3.132

R. Bolotnova, V. Korobchinskaya

{"title":"Comparison of the numerical and self-similar solutions of Sedov’s problem on a point explosion in gas","authors":"R. Bolotnova, V. Korobchinskaya","doi":"10.21662/mfs2020.3.132","DOIUrl":"https://doi.org/10.21662/mfs2020.3.132","url":null,"abstract":"Comparative analysis of solutions of Sedov’s problem of a point explosion in gas for the plane case, obtained by the analytical method and using the open software package of computational fluid dynamics OpenFOAM, is carried out. A brief analysis of methods of dimensionality and similarity theory used for the analytical self-similar solution of point explosion problem in a perfect gas (nitrogen) which determined by the density of uncompressed gas, magnitude of released energy, ratio of specific heat capacities and by the index of geometry of the explosion is given. The system of one-dimensional gas dynamics equations for a perfect gas includes the laws of conservation of mass, momentum, and energy is used. It is assumed that at the initial moment of time there is a point explosion with instantaneous release of energy. Analytical self-similar solutions for the Euler and Lagrangian coordinates, mass velocity, pressure, temperature, and density in the case of plane geometry are given. The numerical simulation of considered process in sonicFoam solver of OpenFOAM package built on the PISO algorithm was performed. For numerical modeling the system of differential equations of gas dynamics is used, including the equations of continuity, Navier-Stokes motion for a compressible medium and conservation of internal energy. Initial and boundary conditions were selected in accordance with the obtained analytical solution using the setFieldsDict, blockMeshDict, and uniformFixedValue utilities. The obtained analytical and numerical solutions have a satisfactory agreement.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"66 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":"114206506","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}

引用次数: 0

Modeling of washout of a well-killing liquid after launching of an oil well 油井投产后压井液的冲蚀模拟

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2020.3.127

A. Topolnikov

{"title":"Modeling of washout of a well-killing liquid after launching of an oil well","authors":"A. Topolnikov","doi":"10.21662/mfs2020.3.127","DOIUrl":"https://doi.org/10.21662/mfs2020.3.127","url":null,"abstract":"The paper presents the results of mathematical modeling of the process of launching and output to the mode of an oil well, which was uploaded by a well-killing liquid at the stage of repairs. After the launching of the electric submergible pump the drop of the bottomhole pressure occurs and the inflow of reservoir fluid begins. As a result the multicomponent mixture is generated inside the well, which consists of oil, associated water, well-killing liquid and free gas, originated from the oil during degassing, and this mixture is pumped out towards wellhead. As soon as the pump characteristics are changed, when the liquid with variable density is pumped out, it is necessary to control the speed of a shaft of the pump for providing the stable pump regime. This problem is solved in the paper for different ratios of densities of well-killing liquid and reservoir fluid by the mathematical modeling of multiphase flow in the well elements and inside the pump. As a mathematical model the one-dimensional quasi-stationary model in approach of drift for description of relative motion of the components is applied, which proved itself well for modeling of non-stationary processes lasting for several days. The comparison of calculated and measuring field parameters is presented. It is shown that the speed of washout of the well-killing liquid from the oil well and the probability of the pump stop due to its head failure depend on the ration of densities of the well-killing liquid and reservoir fluid. It is stated that the monitoring of change of parameters of the pump in time through the mathematical modeling can help to optimize the output to the mode of the well. This allows to avoid stops due to the pump head failure and to diminish the electricity costs.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"14 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":"122510780","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}

引用次数: 0

Study of natural oscillations of oil in a vertical well 直井中石油自然振荡的研究

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2021.3.014

Z. Z. Mamaeva, G. R. Rafikova

{"title":"Study of natural oscillations of oil in a vertical well","authors":"Z. Z. Mamaeva, G. R. Rafikova","doi":"10.21662/mfs2021.3.014","DOIUrl":"https://doi.org/10.21662/mfs2021.3.014","url":null,"abstract":"In the oil industry, an important aspect in the production of hydrocarbons is the control of the state of the well and the study of the near-wellbore zone adjacent to it. For this purpose, various geophysical well survey methods (GIS) are used. One of the methods of well logging is acoustic spectroscopy of wells, where the characteristics of the well and reservoir can be studied by means of excitation of natural oscillations of the fluid. In this paper, the problem of natural oscillations of a fluid in a vertical well, which arose as a result of a sharp opening or closing of the well, is investigated. To describe this process, a mathematical model of natural oscillations of the liquid column in the well, which communicates with the reservoir through the permeable walls of the open area, is constructed using the mass and momentum conservation equation in the well area, the mass conservation equation in the open area of ??the well, and the filtration equation in the reservoir. Taking into account the initial and boundary conditions, an analytical solution was found in the form of standing waves to determine the pressure and velocity of oil in the well. The dependences of the oscillation frequency, decrement and damping factor on the reservoir permeability are shown, the pressure dynamics in the well is given and the amplitude of the oscillations is considered. A comparative analysis of changes in such indicators as oscillation frequency, decrement and damping coefficient has been carried out. The influence of such parameters as the length of the bottomhole zone and the permeability coefficient on the nature of the change in the natural fluctuations of the fluid has been established.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"10 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":"128348898","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}

引用次数: 0

Mathematical model of oil displacement by water in a plane channel 平面通道中水驱油的数学模型

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2020.3.131

A. Nizamova, Valiev A.A. Valiev

{"title":"Mathematical model of oil displacement by water in a plane channel","authors":"A. Nizamova, Valiev A.A. Valiev","doi":"10.21662/mfs2020.3.131","DOIUrl":"https://doi.org/10.21662/mfs2020.3.131","url":null,"abstract":"Unstable displacement of immiscible liquids in a plane channel is a topical research in both theoretical and practical applications. In this paper, we consider a plane channel filled with an incompressible fluid. Over time, another fluid is injected into the channel. The fluids are immiscible. The paper builds a mathematical model of the process of oil displacement by water in a plane channel, which allows further numerical studies and comparison of the results with the obtained experimental data using the example of the Hele-Show cell. The mathematical model for a multiphase, multicomponent flow consists of the Navier-Stokes equations, the equations of conservation of mass, momentum and energy. Modern methods for modeling the dynamics of \"viscous fingers“ are based mainly on numerical methods for solving systems of differential equations using the pressure gradient, viscosity and capillary forces as parameters. The influence of these parameters must be determined experimentally. To solve the problem, a quasi-hydrodynamic approach is used, based on the addition of a certain small parameter and allowing one to describe stable schemes with central differences. The complexity of solving such problems lies in the size of the considered models, which in practice have a wide range of applications from micro-scale to orders of one centimeter. A comprehensive study will allow us to evaluate and analyze the entire process as a whole, as well as to establish flow parameters to improve the efficiency of displacement and increase oil recovery, since in the numerical modeling of the process it is easier to create many independent experiments with the same initial data, in contrast to the experimental study.","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":"130383029","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}

引用次数: 0