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  • Open Access

    ARTICLE

    Mean Densities in Dynamic MathematicalTwo-phase Flow Models

    J. Bonilla1, L.J. Yebra1, S. Dormido2

    CMES-Computer Modeling in Engineering & Sciences, Vol.67, No.1, pp. 13-38, 2010, DOI:10.3970/cmes.2010.067.013

    Abstract This paper presents and discusses a mean densities method applied to a steam-water two-phase flow mathematical model which uses a finite volume method and a staggered grid for discretizing a rigid volume in control volumes, where the thermodynamic properties are calculated. This method is based on the concepts of uniform pressure among all the control volumes and mean density in each control volume, allowing smooth thermodynamic properties, hence avoiding discontinuity at phase boundaries. This method wipes out the chattering problem due to the continuous and differentiable modelling of density and its partial derivatives, which leads More >

  • Open Access

    ARTICLE

    Two-phase flow in complex geometries: A diffuse domain approach

    S. Aland1, J. Lowengrub2, A. Voigt1

    CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.1, pp. 77-108, 2010, DOI:10.3970/cmes.2010.057.077

    Abstract We present a new method for simulating two-phase flows in complex geometries, taking into account contact lines separating immiscible incompressible components. We combine the diffuse domain method for solving PDEs in complex geometries with the diffuse-interface (phase-field) method for simulating multiphase flows. In this approach, the complex geometry is described implicitly by introducing a new phase-field variable, which is a smooth approximation of the characteristic function of the complex domain. The fluid and component concentration equations are reformulated and solved in larger regular domain with the boundary conditions being implicitly modeled using source terms. The… More >

  • Open Access

    ARTICLE

    Convective Boiling in Metallic Foam: Experimental Analysis of the Pressure Loss

    B. Madani1, F. Topin2, L. Tadrist2

    FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.4, pp. 351-368, 2010, DOI:10.3970/fdmp.2010.006.351

    Abstract The present work deals with the hydraulic characterization of two-phase flow with phase change in a channel filled with metallic foam. We provide a general presentation of metallic foams including morphological characteristics, fabrication processes and industrial applications. The experimental facility, which consists of a hydrodynamic loop, the test section, measurement devices, and the data acquisition system, is presented. The Metallic foam sample tested in the present work is manufactured by SCPS (French manufacturer). N-pentane is used as a coolant fluid. The mass velocity values lie between 4 and 49 kg/ m2s, while the heating power More >

  • Open Access

    ARTICLE

    On Flows Driven by Mechanical Stresses in a Two-Phase System

    Yu. Gaponenko1, I. Ryzhkov2, V. Shevtsova3

    FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 75-98, 2010, DOI:10.3970/fdmp.2010.006.075

    Abstract Gas-liquid flows in annulus are analyzed for fluids in large range of viscosity ratios. The geometry corresponds to a liquid bridge co-axially placed into an outer cylinder with solid walls. The internal core consists of solid rods at the bottom and top, while the central part is a relatively short liquid zone filled with viscous liquid and kept in its position by surface tension. The gas enters into the annular duct and entrains initially quiescent liquid. The flow structures in the liquid and gas are obtained numerically for different shapes of solid rods. Solution for More >

  • Open Access

    ABSTRACT

    A Numerical Solution of 2D Buckley-Leverett Equation via Gradient Reproducing Kernel Particle Method

    Hossein M. Shodja1, 2, 3, Alireza Hashemian2, 4

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.3, pp. 57-58, 2009, DOI:10.3970/icces.2009.013.057

    Abstract Gradient reproducing kernel particle method (GRKPM) is a meshless technique which incorporates the first gradients of the function into the reproducing equation of RKPM. Therefore, in two-dimensional space GRKPM introduces three types of shape functions rather than one. The robustness of GRKPM's shape functions is established by reconstruction of a third-order polynomial. To enforce the essential boundary conditions (EBCs), GRKPM's shape functions are modified by transformation technique. By utilizing the modified shape functions, the weak form of the nonlinear evolutionary Buckley-Leverett (BL) equation is discretized in space, rendering a system of nonlinear ordinary differential equations More >

  • Open Access

    ARTICLE

    3D Numerical Modeling of Soluble Surfactant at Fluidic Interfaces Based on the Volume-of-Fluid Method

    A. Alke1, D. Bothe1

    FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 345-372, 2009, DOI:10.3970/fdmp.2009.005.345

    Abstract We present a computational approach based on the Volume-of-Fluid (VOF) method for simulating the influence of a soluble surfactant on the behavior of two-phase systems with deformable interface. Our approach is applicable to diffusion controlled processes, where the relation between the area-specific excess surfactant concentration on the interface and the volume-specific concentration adjacent to the interface is given by an adsorption isotherm. Main issues of the numerical model are an extended surface transport theorem used for describing the interfacial flux and an iso-surface of the VOF-variable used as a connected approximation for the interface. 3D-simulations More >

  • Open Access

    ARTICLE

    A Numerical Solution of 2D Buckley-Leverett Equation via Gradient Reproducing Kernel Particle Method

    Hossein M. Shodja1,2,3, Alireza Hashemian1,4

    CMES-Computer Modeling in Engineering & Sciences, Vol.32, No.1, pp. 17-34, 2008, DOI:10.3970/cmes.2008.032.017

    Abstract Gradient reproducing kernel particle method (GRKPM) is a meshless technique which incorporates the first gradients of the function into the reproducing equation of RKPM. Therefore, in two-dimensional space GRKPM introduces three types of shape functions rather than one. The robustness of GRKPM's shape functions is established by reconstruction of a third-order polynomial. To enforce the essential boundary conditions (EBCs), GRKPM's shape functions are modified by transformation technique. By utilizing the modified shape functions, the weak form of the nonlinear evolutionary Buckley-Leverett (BL) equation is discretized in space, rendering a system of nonlinear ordinary differential equations More >

  • Open Access

    ARTICLE

    A Solenoidal Initial Condition for the Numerical Solution of the Navier-Stokes Equations for Two-Phase Incompressible Flow

    F. Bierbrauer, S.-P. Zhu1

    CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.1, pp. 1-22, 2007, DOI:10.3970/cmes.2007.019.001

    Abstract Recently the use of the one-field formulation in the numerical solution of the Navier-Stokes equations for two-phase incompressible flow has become a very attractive approach in CFD (computational fluid dynamics). While the presence of material discontinuities across fluid interfaces presents some difficulty, it is their combination with a non-solenoidal discontinuous initial velocity field, commonly occurring in the mathematical formulation, that has provided the greatest hindrance in the numerical solution. This paper presents three analytical solutions, the Bounded Creeping Flow, Solenoidal and Conserved Solenoidal Solutions, which are both continuous, incompressible, retain as much of the original More >

  • Open Access

    ARTICLE

    The Influence of Flow Pressure Gradient on Interfacial Wave Properties in Annular Two-Phase Flow at Microgravity and Normal Gravity Conditions

    Huawei Han1, Kamiel S. Gabriel2

    FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.4, pp. 287-298, 2006, DOI:10.3970/fdmp.2006.002.287

    Abstract Data on air-water co-current two-phase annular flow in a tube with an inner diameter of 9.525 mm (3/8 in) were previously collected at both microgravity u-g and normal gravity (1-g) conditions. The data contained measurements of pressure drop, in addition to previously published data of liquid film thickness. This paper presents the results and analysis of the influence of flow pressure gradient on interfacial wave properties of annular flow at both microgravity and normal gravity. The examined wave properties include wave base thickness, wave height (or roughness height), wave spacing, wave speed and wave frequency.… More >

  • Open Access

    ARTICLE

    Two-Phase Flow Simulation by AMMoC, an Adaptive Meshfree Method of Characteristics

    Armin Iske1, Martin Käser2

    CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.2, pp. 133-148, 2005, DOI:10.3970/cmes.2005.007.133

    Abstract Petroleum reservoir modelling requires effective multiscale methods for the numerical simulation of two-phase flow in porous media. This paper proposes the application of a novel meshfree particle method to the Buckley-Leverett model. The utilized meshfree advection scheme, called AMMoC, is essentially a method of characteristics, which combines an adaptive semi-Lagrangian method with local meshfree interpolation by polyharmonic splines. The method AMMoC is applied to the five-spot problem, a well-established model problem in petroleum reservoir simulation. The numerical results and subsequent numerical comparisons with two leading commercial reservoir simulators, ECLIPSE and FrontSim, show the good performance of More >

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