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.

Application of the Volume-of-Fluid Method to the Advection–Condensation Problem

Abstract: The authors demonstrate the application of the volume of fluid (VOF) method, a specialized grid refinement technique, to the numerical simulation of clouds. In particular, it is shown that VOF eliminates most of the well-recognized numerical difficulties (spurious oscillations and/or diffusion in vicinity of a cloud–environment interface) associated with finite-difference Eulerian advection of cloud boundaries. In essence, VOF is a subgrid-scale advection parameterization that accounts for the transport of material interfaces. VOF is an Eulerian approach, as it does not track explicitly material interfaces. Instead, it reconstructs such interfaces using auxiliary dependent variables—the partial volume fractions of immiscible materials within computational cells. A feature of VOF particularly important for cloud modeling is its ability to identify cells with a subgrid-scale cloud–environment interface. Consequently, relevant parameterizations of microphysical processes can be applied consistently ...

Numerical Modeling of Free Surface Dynamics of Melt in an Alternate Electromagnetic Field. Part II: Conventional Electromagnetic Levitation

Abstract: By means of external coupling between electromagnetic (EM) problem in ANSYS and hydrodynamic problem in FLUENT, a numerical model for the liquid metal free surface flow in an alternate EM field has been developed and verified in the first part of the article. Volume of Fluid (VOF) algorithm has been used for tracking of free surface. In this work, improved performance of the model is presented. General validation of the VOF algorithm is performed by comparison of the calculated free oscillations of the liquid column to its analytical solution. The 3D/VOF calculation of coupled EM field and free surface flow with Large Eddy Simulation turbulence description for the first time is applied for modeling of conventional EM levitation. Calculation results are compared with 2D/VOF and 3D/VOF models that use less precise k–e and k–ω SST turbulence formulations. Obtained time-averaged droplet shapes are used for single-phase flow calculations with different turbulence models and free-slip/no-slip velocity conditions at the fixed free surface for validation of the flow. Meanwhile, series of levitation melting experiments are performed for verification of the simulated droplet shapes. In conclusion, parameter impact on the fully developed flow and the levitated droplet shape is discussed.

Investigation of Bubble-Slag Layer Behaviors with Hybrid Eulerian–Lagrangian Modeling and Large Eddy Simulation

Abstract: In ladle metallurgy, bubble–liquid interaction leads to complex phase structures. Gas bubble behavior, as well as the induced slag layer behavior, plays a significant role in the refining process and the steel quality. In the present work, a mathematical model using the large eddy simulation (LES) is developed to investigate the bubble transport and slag layer behavior in a water model of an argon-stirred ladle. The Eulerian volume of fluid model is adopted to track the liquid steel–slag–air free surfaces while the Lagrangian discrete phase model is used for tracking and handling the dynamics of discrete bubbles. The bubble coalescence is considered using O’Rourke’s algorithm to solve the bubble diameter redistribution and bubbles are removed after leaving the air–liquid interface. The turbulent liquid flow that is induced by bubble–liquid interaction is solved by LES. The slag layer fluactuation, slag droplet entrainment and spout eye open–close phenomenon are well revealed. The bubble diameter distribution and the spout eye size are compared with the experiment. The results show that the hybrid Eulerian–Lagrangian–LES model provides a valid modeling framework to predict the unsteady gas bubble–slag layer coupled behaviors.

Two-Dimensional Analysis of Dam-Break Flow in Vertical Plane

Abstract: This work presents numerical computations for the analysis of Dam-Break Flow using two-dimensional flow equations in a vertical plane. The numerical model uses the general approach of the simplified marker and cell method combined with the volume of fluid approach for the surface tracking. The time evolution of flow depth at the dam site and the evolution of the pressure distribution are investigated for both wet and dry bed conditions. The effect of the initially nonhydrostatic state on the long term surface profile and wave velocity are studied. These long term effects are found to be marginal in the case of wet-bed conditions, but are significant in dry-bed conditions. The dry-bed tip velocity immediately after the dam break, computed numerically, compares well with analytical results published previously. The time taken to obtain a constant flow depth at the dam site increases with decreasing initial depth ratio. The numerical result for this time elapse for dry-bed conditions is close to the experime...