Volume of fluid method

About: Volume of fluid method is a research topic. Over the lifetime, 5338 publications have been published within this topic receiving 116760 citations.

Simulation of Taylor Flow in Capillaries Based on the Volume-of-Fluid Technique

Abstract: Taylor flow, a flow regime characterized by Taylor bubbles separated by liquid slugs that do not contain entrained micro bubbles, is a predominant gas−liquid two-phase flow regime in capillaries and minichannels (channels with hydraulic diameters in the 0.1−1 mm range), and it occurs in monolithic catalytic converters and other multiphase reactors. Taylor flow regime is morphologically relatively simple and has been modeled in the past using computational fluid dynamics (CFD) methods. However, most of the past CFD models have either assumed a fixed gas−liquid interfacial geometry or have modeled the gas−liquid interphase movement based on the method of spines, which imposes some restrictions on the free movement of the interface. In this study, we examine the feasibility of CFD modeling of the Taylor flow regime in capillaries by using the volume-of-fluid (VOF) technique for the motion of the gas−liquid interphase. It is shown that such a model predicts well the experimental data and empirical correlation...

Simulation of condensation flow in a rectangular microchannel

Abstract: The condensation flow of the refrigerant FC-72 in a rectangular microchannel with a 1-mm hydraulic diameter is numerically studied using the volume of fluid (VOF) model. The heat transfer related to the condensation is taken into account by a thermal equilibrium model assuming the interface temperature is at saturation. The numerical method is validated against experiments from the literature and well predicts the flow patterns along the microchannel. The vapor phase in the microchannel forms a continuous column with a decreasing diameter from upstream to downstream. Slugs are periodically generated at the head of the column. Decreasing the wall cooling heat flux or increasing the flow mass flux increases the vapor column length. Waves along the interface cause necks in the column and locally increase the vapor velocity and decrease the pressure, facilitating breakage of the vapor column into slugs. The liquid temperature is close to saturation near the interface and lower downstream and in the thin liquid layer close to the cooling surface. The initial bubble size increases with increasing flow mass flux or decreasing cooling heat flux.

Validation of the S-CLSVOF method with the density-scaled balanced continuum surface force model in multiphase systems coupled with thermocapillary flows

Abstract: Summary Three numerical methods, namely, volume of fluid (VOF), simple coupled volume of fluid with level set (S-CLSVOF), and S-CLSVOF with the density-scaled balanced continuum surface force (CSF) model, have been incorporated into OpenFOAM source code and were validated for their accuracy for three cases: (i) an isothermal static case, (ii) isothermal dynamic cases, and (iii) non-isothermal dynamic cases with thermocapillary flow including dynamic interface deformation. Results have shown that the S-CLSVOF method gives accurate results in the test cases with mild computation conditions, and the S-CLSVOF technique with the density-scaled balanced CSF model leads to accurate results in the cases of large interface deformations and large density and viscosity ratios. These show that these high accuracy methods would be appropriate to obtain accurate predictions in multiphase flow systems with thermocapillary flows. Copyright © 2016 John Wiley & Sons, Ltd.