HYDRODYNAMIC FEATURES OF SUSPENSIONS AND EMULSIONS FLOWS.

This scientific article is devoted to the problems associated with the flow of suspensions and emulsions and some simplifications of the real picture of the flow of a polydisperse medium are made. It is also stipulated that differential equations characterizing the motion of suspensions and emulsions should take into account the fundamental discontinuity of the medium and the physicochemical processes of heat and mass transfer occurring in it. Taking into account all these factors, a general equation for multiphase systems is proposed with certain simplifications that do not change. The behavior of particles in two-phase systems, their concentration, collision and coagulation are considered. As a result, it was concluded that there is a multifactorial interaction and mutual influence of both phases in a dispersed flow. A differential equation of motion of a single i-th spherical particle in suspension was proposed, and an equation describing the drag force of a solid spherical particles. Equations of conservation of mass and momentum are presented for one-dimensional laminar motion of two incompressible phases in a gravity field with the same pressure in the phases. Having studied the parameters of the flow of fine particles in a turbulent gas flow, some assumptions were made. It was found that the pulsating motion of particles, performed by them during one period of gas pulsations, can be represented as a change in the pulsating gas velocity in time. The parameter of entrainment of particles by a pulsating medium is an important characteristic in determining the transport coefficients in a turbulent flow. It is concluded that the presence of various kinds of particles in the liquid complicates the problem of solving hydromechanical problems in turbulent and laminar flow, and the assumptions given in the work facilitate the study of this problem.

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Development of Euler-Euler LES Approach for Gas-Particle Turbulent Jet Flow

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2006-98110 ◽

2006 ◽

Cited By ~ 5

Author(s):

Eleonore Riber ◽

Mathieu Moreau ◽

Olivier Simonin ◽

Be´ne´dicte Cuenot

Keyword(s):

Gas Flow ◽

Turbulent Jet ◽

Simulation Approach ◽

Number Density ◽

Two Phase ◽

Eddy Simulation ◽

Large Eddy ◽

Homogeneous Particle ◽

Turbulent Jet Flow ◽

Turbulent Gas Flow

A Large Eddy Simulation approach for Eulerian-Eulerian dispersed two-phase flow is presented. It is shown that not only the Random Uncorrelated Motion but also Sub-Grid Scales term modeling the unresolved field in the particle mesoscopic momentum transport equation and the particle Random Uncorrelated Energy need to be accounted for. Simulations of a non-homogeneous particle laden turbulent gas flow allow to compare dispersed phase quantities such as number density, time-averaged and rms mesoscopic velocity, fluid-particle correlations with experimental results.

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Micromodel Study on Pore Scale Mechanisms associated with Permeability Impairment in Porous Media

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0071 ◽

2020 ◽

Author(s):

Safna Nishad ◽

Riyadh Al-Raoush

Keyword(s):

Porous Media ◽

Gas Flow ◽

Fine Particles ◽

Gas Production ◽

Polystyrene Latex ◽

Continental Margins ◽

Pore Scale ◽

Two Phase ◽

Hydrate Bearing Sediments ◽

Permeability Impairment

Recently, researchers have been attracted towards the gas production from hydrate bearing sediments considering its abundance in marine continental margins and persisting demand for alternate energy. Dissociation of hydrate into gas and water is the preliminary technique for gas production in hydrate bearing sediments. Expanded fluid volume and gas pressure upon dissociation detach the fines from the grain surface and result in pore throat entrapment. Migration of fines associated with gas flow greatly influence the alteration of permeability of the sediment by clogging pore throats in the flow path. A pore-scale visualization study was implemented to provide a clear insight into the actual mechanisms associated with mobilization and clogging of fines during two-phase flow through a microfluidic chip. Carboxylate modified polystyrene latex particles deposited in the porous media were migrated during drainage with CO2 gas. The detachment of fine particles from the grain surfaces was observed and were retained on the new interface; gas-water interface. The images and videos captured during the experiment were helpful in observing additional pore scale mechanisms responsible for permeability impairment in the porous media. Interface pinning, deformation and resistance to coalescence were found to be other mechanisms in addition to pore clogging.

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Effect of Stefan flow on drag coefficient of reactive spherical particles in gas flow

Proceeding of THMT-18. Turbulence Heat and Mass Transfer 9 Proceedings of the Ninth International Symposium On Turbulence Heat and Mass Transfer ◽

10.1615/thmt-18.1250 ◽

2018 ◽

Author(s):

T.R. Jayawickrama ◽

N.E.L. Haugen ◽

M.U. Babler ◽

K. Umeki

Keyword(s):

Drag Coefficient ◽

Gas Flow ◽

Spherical Particles ◽

Stefan Flow

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The influence of the Stokes and Archimedes forces on the stability of a two-phase flow

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2003.1.020 ◽

2003 ◽

Vol 3 ◽

pp. 266-270

Author(s):

B.H. Khudjuyerov ◽

I.A. Chuliev

Keyword(s):

Spectral Method ◽

Stability Region ◽

Gas Flow ◽

Two Phase Flow ◽

Solid Phase ◽

Stability Characteristic ◽

Phase Flow ◽

Two Phase ◽

The Stability

The problem of the stability of a two-phase flow is considered. The solution of the stability equations is performed by the spectral method using polynomials of Chebyshev. A decrease in the stability region gas flow with the addition of particles of the solid phase. The analysis influence on the stability characteristic of Stokes and Archimedes forces.

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Modeling of pressure losses on friction in three-layer laminar flows

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2003.1.015 ◽

2003 ◽

Vol 3 ◽

pp. 208-219

Author(s):

A.M. Ilyasov

Keyword(s):

Pressure Loss ◽

Gas Flow ◽

Mutual Influence ◽

Fluid Model ◽

Immiscible Liquid ◽

Laminar Flows ◽

Pressure Losses ◽

Flow Parameters ◽

Interphase Boundaries ◽

Closing Relations

In this paper we propose a model for determining the pressure loss due to friction in each phase in a three-layer laminar steady flow of immiscible liquid and gas flow in a flat channel. This model generalizes an analogous problem for a two-layer laminar flow, proposed earlier. The relations obtained in the final form for the pressure loss due to friction in liquids can be used as closing relations for the three-fluid model. These equations take into account the influence of interphase boundaries and are an alternative to the approach used in foreign literature. In this approach, the wall and interphase voltages are approximated by the formulas for a single-phase flow and do not take into account the mutual influence of liquids on the loss of pressure on friction in phases. The distribution of flow parameters in these two models is compared.

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Simulation of mechanically stirred two-phase liquid-gas flow

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19861001 ◽

1986 ◽

Vol 51 (5) ◽

pp. 1001-1015 ◽

Cited By ~ 2

Author(s):

Ivan Fořt ◽

Vladimír Rogalewicz ◽

Miroslav Richter

Keyword(s):

Spatial Distribution ◽

Velocity Field ◽

Gas Flow ◽

Liquid Velocity ◽

Model Parameters ◽

Two Phase ◽

Mean Velocity ◽

Rushton Turbine ◽

Low Viscosity ◽

Volumetric Gas Flow Rate

The study describes simulation of the motion of bubbles in gas, dispersed by a mechanical impeller in a turbulent low-viscosity liquid flow. The model employs the Monte Carlo method and it is based both on the knowledge of the mean velocity field of mixed liquid (mean motion) and of the spatial distribution of turbulence intensity ( fluctuating motion) in the investigated system - a cylindrical tank with radial baffles at the wall and with a standard (Rushton) turbine impeller in the vessel axis. Motion of the liquid is then superimposed with that of the bubbles in a still environment (ascending motion). The computation of the simulation includes determination of the spatial distribution of the gas holds-up (volumetric concentrations) in the agitated charge as well as of the total gas hold-up system depending on the impeller size and its frequency of revolutions, on the volumetric gas flow rate and the physical properties of gas and liquid. As model parameters, both liquid velocity field and normal gas bubbles distribution characteristics are considered, assuming that the bubbles in the system do not coalesce.

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The effect of solid particle size and concentrations on internal flow and external characteristics of the dense fine particles solid–liquid two-phase centrifugal pump under low flow condition

AIP Advances ◽

10.1063/5.0054275 ◽

2021 ◽

Vol 11 (8) ◽

pp. 085309

Author(s):

Yanping Wang ◽

Weiqin Li ◽

Tielin He ◽

Chuanfeng Han ◽

Zuchao Zhu ◽

...

Keyword(s):

Particle Size ◽

Centrifugal Pump ◽

Solid Particle ◽

Flow Condition ◽

Fine Particles ◽

Internal Flow ◽

Low Flow ◽

Two Phase ◽

Solid Liquid ◽

External Characteristics

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Two-Phase Flows in Mini-/Micro-Gas Flow Channels of PEM Fuel Cells

Volume 6B: Energy ◽

10.1115/imece2013-66070 ◽

2013 ◽

Author(s):

Sung Chan Cho ◽

Yun Wang

Keyword(s):

Pressure Drop ◽

Gas Flow ◽

Fluid Model ◽

Pem Fuel Cells ◽

Two Phase ◽

Micro Gas Flow ◽

Two Fluid Model ◽

The Impact ◽

Two Fluid ◽

Phase Pressure

In this paper, two-phase flow dynamics in a micro channel with various wall conditions are both experimentally and theoretically investigated. Annulus, wavy and slug flow patterns are observed and location of liquid phase on different wall condition is visualized. The impact of flow structure on two-phase pressure drop is explained. Two-phase pressure drop is compared to a two-fluid model with relative permeability correlation. Optimization of correlation is conducted for each experimental case and theoretical solution for the flows in a circular channel is developed for annulus flow pattern showing a good match with experimental data in homogeneous channel case.

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