Multiphase Systems最新文献_第7页

Shock waves dynamics and evolution of vortex formation during the interaction of spherical air pulse with aqueous foam layer 球形空气脉冲与泡沫水层相互作用的激波动力学及涡形成演化

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.2.011

E. F. Gainullina

{"title":"Shock waves dynamics and evolution of vortex formation during the interaction of spherical air pulse with aqueous foam layer","authors":"E. F. Gainullina","doi":"10.21662/mfs2019.2.011","DOIUrl":"https://doi.org/10.21662/mfs2019.2.011","url":null,"abstract":"The numerical study of the powerful air spherical shock-wave pulse interaction with the protective aqueous foam barrier with the initial liquid volume fraction of 0.2 is carried out. The foam layer thickness is selected to satisfy the condition of the non-reflection of compression wave from the foam external boundary at the considered time intervals. In studying the wave flows dynamics, we used the assumption of the foam structure destruction into the microdrops suspension behind the strong shock wave front. The two-phase medium is described on the basis of the gas-droplet mixture model, which includes the laws of conservation of mass, momentum and energy for each phase in accordance with the single-pressure, two-speed, two-temperature approximations in a two-dimensional axisymmetric formulation. The Schiller–Naumann model is used for taking into account the interfacial drag forces. The contact heat transfer influence at the interface between the phases is taken into account by the Ranz–Marshall model. To describe the properties of air and water, the Peng–Robinson and perfect fluid equations of state are used. The numerical implementation of the model is carried out using the OpenFOAM open-source software with the two-step PIMPLE algorithm. The numerical study results are presented as spatial distributions of pressure fields, velocities and streamlines. The significant attenuation of the spherical shock wave intensity during its interaction with the aqueous foam layer has been established. The causes and dynamics of the toroidal vortices series formation in the gas region behind the shock front are investigated. The results reliability is confirmed by comparison with the solutions of the similar problem, found by another numerical method.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"37 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":"127612424","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

Solid-state explosion simulation in COMSOL Multiphysics COMSOL Multiphysics中的固体爆炸模拟

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.4.032

A. Belov, O. V. Kopchenov, A. O. Skachkov, D. E. Ushakov

{"title":"Solid-state explosion simulation in COMSOL Multiphysics","authors":"A. Belov, O. V. Kopchenov, A. O. Skachkov, D. E. Ushakov","doi":"10.21662/mfs2019.4.032","DOIUrl":"https://doi.org/10.21662/mfs2019.4.032","url":null,"abstract":"In this work, the propagation of blast waves in a rock mass caused by a short-term load is considered. Such loads are typical in the construction of tunnels and other excavations using blasting. For modeling by the finite element method, the cross-platform software COMSOL Multiphysics 5.4 was used. The explosion is reproduced in a steel tank whose steel grade is EN 1.7220 4CrMo4. The medium in the tank has the properties of granite rock (Young’s modulus E = 50 GPa, Poisson’s ratio ν = 2/7, Density ρ = 2700 kg/m3 ). The sphere is also a body having the properties of granite. Set to clarify the geometry of the explosion and the area where the mesh is indicated. The tank has dimensions: 10.39 m in length and diameter 2.9 m. The wall thickness of the tank is 0.01 m. To model the explosion, the Solid Mechanics interface was used, located in the Structural Mechanics branch, based on solving equations of motion together with a model for solid material. Results such as displacement, stress, and strain are calculated. The force per unit volume (Fv) is specified by the normal pressure in the sphere. Also, the tensile strength was calculated for this steel grade: upon reaching a certain pressure in the tank (7.26 MPa), the simulation stops, and the system notifies at what point in time the destruction occurred. A Time Dependent Study is used. Seconds are used as a unit of time. The task is calculated from 0 seconds (initial moment of time) to 0.003 seconds (final moment of time) with a construction step of 0.00005.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"59 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":"122101105","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 dynamic phenomena in aqueous foams (review) 水泡沫动力学现象的建模(综述)

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2022.1.004

R. Bolotnova, E. F. Gainullina

{"title":"Modeling of dynamic phenomena in aqueous foams (review)","authors":"R. Bolotnova, E. F. Gainullina","doi":"10.21662/mfs2022.1.004","DOIUrl":"https://doi.org/10.21662/mfs2022.1.004","url":null,"abstract":"Analytical review of investigations aimed at studying the aqueous foam behavior under the shock-wave impact is given. The main approaches and theoretical approximations used in the development of aqueous foams models are analyzed. The two-phase gas-drop model of aqueous foam is considered, based on the laws of conservation of mass, momentum, and energy in accordance with one-pressure, two-velocity, two-temperature approximations. The model describes foam dynamics under a high - intensity impact, which destroys the foam structure into microdroplets, and takes into account interfacial heat transfer, interfacial drag and virtual mass forces and the phenomenon of foam syneresis (deposition). The numerical implementation of the model was carried out using new solvers in the OpenFOAM software. The analysis of the numerical solution of the spherical explosion in aqueous foam is given for the conditions of the literature experimental data. The syneresis influence on the intensity and velocity of shock wave propagation is shown. The two-phase model of aqueous foam is considered, which takes into account its elastic- viscous-plastic properties for conditions of weak impact that does not destroy foam structure. The model takes into account the elastic properties of aqueous foam at small deformations and describes it as a non-Newtonian fluid when the foam changes its state from the elastic to viscoplastic. The weak shock wave propagation dynamics in the layer of aqueous foam with the formation of a two-wave structure, consisting of the main wave and the elastic precursor ahead of it, is analyzed. The process of local aqueous foam compaction zone formation, followed by a gaseous region, behind the shock wave front is shown. The reliability of the obtained results of numerical studies is confirmed by their agreement with the literature experimental data.","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":"117145698","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

Group classification of third order nonlinear wave equations chain’s 三阶非线性波动方程链的群分类

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2020.3.136

O. K. Babkov, G. Z. Mukhametova

引用次数: 0

The topological soliton decay in a linear defect of the domain structure of twisted nematic 拓扑孤子在扭曲向列结构的线性缺陷中衰变

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2022.3.012

V. Delev

{"title":"The topological soliton decay in a linear defect of the domain structure of twisted nematic","authors":"V. Delev","doi":"10.21662/mfs2022.3.012","DOIUrl":"https://doi.org/10.21662/mfs2022.3.012","url":null,"abstract":"In this paper, the topological soliton decay in an oscillating linear defect of electroconvective structure (Williams domains) arising in π/2 twisted nematic liquid crystal are studied. In contrast to planarly oriented nematics, hydrodynamic flows in the domains of a twisted nematic have a helical character. Since, in addition to the tangential velocity component, there is also axial component, the direction of which is opposite in neighboring domains. This feature leads to the formation of stable localized extended objects — linear defects oriented normal to Williams domains. With increasing applied voltage, “zig-zag” oscillations occurs in linear defects. The boundaries between the “zig” and “zag“ states are classical dislocations. It has been found, that the dislocation, moving along the core of the defect, breaks up into an antidislocation and two dislocations. Unlike case of planarly oriented nematics, dislocations are not isolated from each other by unperturbed rolls but remain “bound” by hydrodynamic flows within the core of a linear defect. It is assumed that the splitting of the dislocation occurs as a result of the local instability of the orientational twist mode of the director n due to its strong coupling with the hydrodynamic velocity. In the framework of the sine–Gordon equation, in the presence of a dissipative term and spatial perturbations, the mechanism of a topological soliton (kink) decay into antisoliton and two solitons is considered.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"17 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":"116782611","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 multiphase flow propagation for the case of underwater pipeline damage 水下管道损伤情况下多相流传播数学模型

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.2.020

S. R. Kildibaeva, E. T. Dalinskij, G. R. Kildibaeva

{"title":"Mathematical model of multiphase flow propagation for the case of underwater pipeline damage","authors":"S. R. Kildibaeva, E. T. Dalinskij, G. R. Kildibaeva","doi":"10.21662/mfs2019.2.020","DOIUrl":"https://doi.org/10.21662/mfs2019.2.020","url":null,"abstract":"The paper deals with the case of damage to the underwater pipeline through which oil and associated gas are transported. The process of oil and gas migration is described by the flow of a multiphase submerged jet. At the initial moment, the temperature of the incoming hydrocarbons, their initial velocity, the temperature of the surrounding water, the depth of the pipeline is known. The paper considers two cases of different initial parameters of hydrocarbon outflow from the pipeline. In the first case, the thermobaric environmental conditions correspond to the conditions of hydrate formation and stable existence. Such a case corresponds to the conditions of the hydrocarbons flow in the Gulf of Mexico. In the second case, hydrate is not formed. Such flows correspond to the cases of oil transportation through pipelines in the Baltic sea (for example, Nord stream–2). The process of hydrate formation will be characterized by the following dynamics of the bubble: first, it will be completely gas, then a hydrate shell (composite bubble) will begin to form on its surface, then the bubble will become completely hydrate, which will be the final stage. The integral Lagrangian control volume method will be considered for modeling the dynamics of hydrocarbon jet propagation. According to this method, the jet is considered as a sequence of elementary volumes. When modeling the jet flow, the laws of conservation of mass, momentum and energy for the components included in the control volume are taken into account. The equations are used taking into account the possible formation of hydrate. Thermophysical characteristics of hydrocarbons coming from the damaged pipeline for cases of deep-water and shallow-water pipeline laying are obtained. The trajectories of hydrocarbon migration, the dependence of the jet temperature and density on the vertical coordinate are analyzed.","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":"114248239","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

Model of acid solution flow in a porous half-space 酸溶液在多孔半空间中的流动模型

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2019.3.027

A. M. Il’yasov

{"title":"Model of acid solution flow in a porous half-space","authors":"A. M. Il’yasov","doi":"10.21662/mfs2019.3.027","DOIUrl":"https://doi.org/10.21662/mfs2019.3.027","url":null,"abstract":"To increase oil recovery of weakly permeable carbonate rock, acid treatments with a weakly concentrated aqueous solution of hydrochloric acid are used. There can be various modes of dissolution of rocks depending on the injection rate of the acid solution in the breed from complete dissolution of the skeleton of the rock with a solid front at low speeds the injection to the emergence of long, single wormhole at high speeds of injection. A one-dimensional unsteady model of the flow of an aqueous hydrochloric acid solution in a porous carbonate rock is developed taking into account the movement of the front of the carbonate rock dissolution reaction. The boundary conditions under which the obtained system of equations is reduced to a self-similar system of equations of the fifth order are found. In contrast to self-similar filtration of a Newtonian fluid in the half space, the degree of dependence of self-similar independent variable is equal to − 3/2, and the dependent variables are the porosity and rate of filtration depend on the exponent of the dependence of rock permeability from changes in porosity after acid treatment. A one-dimensional non-stationary model of the flow of an aqueous solution of hydrochloric acid in a porous carbonate rock was developed taking into account the movement of the front of the dissolution reaction of carbonate rock. Boundary conditions are found under which the resulting system of equations reduces to a self-similar system of fifth-order equations. Unlike self-similar filtering of Newtonian fluid in half-space, the degree of dependence of the self-similar independent variable is −3/2, and the dependent variables (porosity and speed) of filtration depend on the degree of dependence of rock permeability on the change in porosity after acid treatment.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"26 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114118351","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

Investigation of the spectral characteristics of a thermoviscous fluid flow in an annular channel 环状通道中热粘性流体流动的频谱特性研究

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2022.3.017

A. Nizamova, V. Kireev, S. Urmancheev

{"title":"Investigation of the spectral characteristics of a thermoviscous fluid flow in an annular channel","authors":"A. Nizamova, V. Kireev, S. Urmancheev","doi":"10.21662/mfs2022.3.017","DOIUrl":"https://doi.org/10.21662/mfs2022.3.017","url":null,"abstract":"The flow of a thermoviscous model fluid in an annular channel with a given temperature field is considered. The problem of the stability of the flow of a thermoviscous fluid is solved on the basis of the generalized equation by the spectral method of expansion in Chebyshev polynomials of the first kind. The effect of taking into account the exponential dependence of the fluid viscosity on temperature and channel geometry on the spectral characteristics of the equation of hydrodynamic stability of an incompressible fluid flow in a flat channel for various wall temperatures is studied. Spectral patterns of eigenvalues of the generalized equation are constructed. The spectral characteristics determine the structure of the eigenfunctions and the critical parameters of the flow of a thermoviscous fluid. In this case, the eigenfunctions demonstrate the behavior of transverse velocity perturbations, their possible growth or decay with time. It is shown that the structure of the spectra largely depends both on the properties of the liquid, determined by the index of the functional dependence of viscosity, and on the geometry of the channel. It has been established that for small values of the thermoviscosity parameter, the spectrum is comparable to the spectrum for an isothermal fluid flow in a flat channel, however, as it increases, the number of eigenvalues and their density increase, that is, there are more points at which the problem has nonzero amplitudes of transverse velocity perturbations. The stability of a thermoviscous fluid flow depends on the presence of an eigenvalue with a positive imaginary part among the entire set of found eigenvalues for fixed parameters of the Reynolds number and wave number. It is shown that, at fixed values of the Reynolds number and wave number, the flow can become unstable with an increase in the thermoviscosity parameter.","PeriodicalId":309215,"journal":{"name":"Multiphase Systems","volume":"125 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":"130667860","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

Simulation of the sedimentation of a swirling flow of a rarefied granular medium in a cylindrical region by MP-PIC method 用MP-PIC方法模拟稀薄颗粒介质在圆柱形区域内的旋流沉降

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2021.3.017

K. Bashirova

引用次数: 0

Seminars of the Mavlyutov Institute of Mechanics UFRS RAS 2021 (abstracts) 马夫柳托夫力学研究所UFRS RAS 2021研讨会(摘要)

Multiphase Systems Pub Date : 1900-01-01 DOI: 10.21662/mfs2021.3.019

K. V. Moiseev

引用次数: 0