Volume of Fluid (VOF) type advection methods in two-phase flow: A comparative study

Severe limitations of the use of three-dimensional computational fluid dynamics codes (CFD) arise when trying to simulate multiphase flow in long pipes due to time constraints. 1D codes for two-phase flow, based on two-fluid models, are fast but are known to be accurate only when the velocities are within the Kelvin-Helmholtz inviscid limit [1]. An alternative is to carry out a two-dimensional CFD simulation of a channel based on the Volume of Fluid (VOF) model. 2D CFD has a wider applicability range compared to 1D, it does not have the issue of ill-posedness and it also has better turbulence models built in. Again compared to 1D the 2D VOF model has a better interface description and wall treatment. In this paper a novel method is introduced that allows swift simulations of pipeline two-phase flow in the stratified and slug flow regime, by approximating the pipe as a channel and with a methodology that solves the problem of the interfacial velocity differences, inherent in the volume of fluid model. An initial validation using the wave growth problem has already been carried out [2]. Here a set consisting of 92 experimental cases in the slug flow regime has been simulated with 2D CFD, and the simulation results showed a good agreement with experimental results. Discussions in the paper include also the question of the range of applicability for 2D CFD, and the advantages and disadvantages compared to 3D CFD and also to 1D code based on the two-fluid model. Shear stresses are then extracted from the 2D CFD simulations and used to recalibrate the friction factors [3] used in the 1D code.

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Direct simulations of two-phase flow experiments of different geometry complexities using Volume-of-Fluid (VOF) method

Chemical Engineering Science ◽

10.1016/j.ces.2018.10.029 ◽

2019 ◽

Vol 195 ◽

pp. 820-827 ◽

Cited By ~ 8

Author(s):

X. Yin ◽

I. Zarikos ◽

N.K. Karadimitriou ◽

A. Raoof ◽

S.M. Hassanizadeh

Keyword(s):

Two Phase Flow ◽

Volume Of Fluid ◽

Vof Method ◽

Phase Flow ◽

Two Phase ◽

Flow Experiments

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An Improved Volume of Fluid Method for Two-Phase Flow Computations on Collocated Grid System

Journal of Heat Transfer ◽

10.1115/1.4002981 ◽

2011 ◽

Vol 133 (4) ◽

Cited By ~ 4

Author(s):

Dong-Liang Sun ◽

Yong-Ping Yang ◽

Jin-Liang Xu ◽

Wen-Quan Tao

Keyword(s):

Two Phase Flow ◽

Stokes Equations ◽

Volume Of Fluid ◽

Vof Method ◽

Navier Stokes ◽

Phase Flow ◽

Volume Of Fluid Method ◽

Two Phase ◽

Navier Stokes Equations ◽

Collocated Grid

An improved volume of fluid method called the accurate density and viscosity volume of fluid (ADV-VOF) method is proposed to solve two-phase flow problems. The method has the following features: (1) All operations are performed on a collocated grid system. (2) The piecewise linear interface calculation is used to capture interfaces and perform accurate estimations of cell-edged density and viscosity. (3) The conservative Navier–Stokes equations are solved with the convective term discretized by a second and third order interpolation for convection scheme. (4) A fractional-step method is applied to solve the conservative Navier–Stokes equations, and the BiCGSTAB algorithm is used to solve the algebraic equations by discretizing the pressure-correction equation. The above features guarantee a simple, stable, efficient, and accurate simulation of two-phase flow problems. The effectiveness of the ADV-VOF method is verified by comparing it with the conventional volume of fluid method with rough treatment of cell-edged density and viscosity. It is found that the ADV-VOF method could successfully model the two-phase problems with large density ratio and viscosity ratio between two phases and is better than the conventional volume of fluid method in this respect.

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