Numerical simulation of multiphase flows using an enhanced Volume-Of-Fluid (VOF) method

2021 ◽  
pp. 106956
Author(s):  
Faroogh Garoosi ◽  
Kamel Hooman
Keyword(s):  
Numerical Simulation ◽  
Multiphase Flows ◽  
Volume Of Fluid ◽  
Vof Method

Simulation of Multiphase Flows in Complex Geometry Using a Hybrid Method Combining the Multi-Fluid and the Volume-of-Fluid (VOF) Approaches

2002 ◽  
Author(s):  
Jaehoon Han ◽  
Ales Alajbegovic
Keyword(s):  
Multiphase Flow ◽  
Hybrid Method ◽  
Multiphase Flows ◽  
Complex Geometry ◽  
Fluid Model ◽  
Simple Algorithm ◽  
Volume Of Fluid ◽  
Vof Method ◽  
Computational Method ◽  
Small Scale

A computational method combining the multi-fluid and the Volume-of-Fluid (VOF) approaches is presented to simulate industrial multiphase flows in complex geometry. This method is particularly applicable for flows where well-defined interfaces between different phases/fluids co-exist with small-scale multiphase structures. The interfaces in relatively large scales (that can be accurately resolved on a computational mesh with a practical size) are tracked by the VOF method, whereas the small scale multiphase flow structures (that are too computationally expensive to be explicitly tracked by the VOF method) are accounted for by using the multi-fluid approach. In order to provide more computational flexibility, any two of the phases tracked by the multi-fluid approach can either have different velocities (two-fluid model) or share the same velocities (equilibrium model). The hybrid method presented here enables efficient simulation of complex flows with multiple phases/fluids on arbitrary-shaped unstructured meshes. It is fully implemented in the commercial CFD software, AVL FIRE/SWIFT. The governing equations are discretized based on a finite volume method (FVM) and the pressure field is obtained using the SIMPLE algorithm. The effect of surface tension is also included for the phases tracked by the VOF method using a Continuum Surface Force (CSF) model. Application to a well-established example of multiphase flow—a Taylor bubble rising inside a stagnant liquid—is presented to demonstrate the capability of the method.

The Direct Numerical Simulation of the Rising Gas Bubble With the Volume of Fluid (VOF) Method

2011 ◽  
Author(s):  
Shuji Hironaka ◽  
Saki Manabe ◽  
Yuki Fujisawa ◽  
Gen Inoue ◽  
Yosuke Matsukuma ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Volume Fraction ◽  
Fluid Model ◽  
Volume Of Fluid ◽  
Vof Method ◽  
Phase Flow ◽  
Actual Behavior ◽  
Simulation Code ◽  
Advantages And Disadvantages

A gas-liquid two phase flow is complicated and it has not been understood well thus far, in spite of extensive investigation. Numerical simulation is a potential approach to understand this phenomenon. Although a number of studies have been conducted to understand the behavior of bubbles on the basis of computational fluid dynamics (CFD), it is difficult to completely simulate a complicated three-phase flow, including coalescence and breakup of bubbles. Although the two-fluid model based on the semi-empirical model can well estimate the actual behavior of the system in which the equations are derived, the estimation over the applicable region of equations does not always agree with the actual result. Since the 1960s, various procedures have been proposed to directly track the free surface between two phases, for example, the adaptive mesh method and the particle method. Although each of these methods has certain advantages and disadvantages, the volume of fluid (VOF) method is the most acceptable method for capturing the free surface accurately and clearly. However, a concern related to this method is the maintenance of a constant volume of the fluid. In this study, a simulation code using the VOF method is developed in order to estimate the behavior of bubbles in a vertical pipe. Further, an offset of the volume fraction is introduced to stably calculate and minimize the volume fluctuation. The effect of the surface tension is also built into the program in order to estimate the behavior of the bubbles rising through the liquid medium. The simulations of the collapsed water column and a single rising bubble are conducted with the proposed simulation code. Consequently, we confirm that these results fairly agree with the experimental ones.

VOLUME OF FLUID MODEL FOR NUMERICAL SIMULATION OF VEGETATED FLOWS

2008 ◽  
Vol 14 (2) ◽  
pp. 72-87 ◽  
Author(s):  
Koustuv Debnath ◽  
Amartya Kumar Bhattacharya ◽  
Biswanath Mahato ◽  
Agnimitro Chakrabarti
Keyword(s):  
Numerical Simulation ◽  
Fluid Model ◽  
Volume Of Fluid ◽  
Volume Of Fluid Model

Numerical simulation of free ascension and coaxial coalescence of air bubbles using the volume of fluid method (VOF)

2018 ◽  
Vol 161 ◽  
pp. 47-59 ◽  
Author(s):  
W. Abbassi ◽  
S. Besbes ◽  
M. Elhajem ◽  
H. Ben Aissia ◽  
J.Y. Champagne
Keyword(s):  
Numerical Simulation ◽  
Volume Of Fluid ◽  
Air Bubbles ◽  
Volume Of Fluid Method

Numerical Simulation of Droplet Ejection Based on VOF Method

2014 ◽  
Vol 548-549 ◽  
pp. 1257-1264 ◽  
Author(s):  
Xiao Yong Suo
Keyword(s):  
Numerical Simulation ◽  
Surface Tension ◽  
Numerical Model ◽  
Physical Properties ◽  
Vof Method ◽  
Numerical Results ◽  
Droplet Ejection ◽  
Ejection Process ◽  
Ink Jet ◽  
Jet Nozzle

Taking ejection process of the ink droplets from ink-jet nozzle as the prototype, a similar numerical model of droplet ejection was established. The VOF method was applied to track the interface of droplet ejection process and it is shown that the numerical results simulated by the VOF method were accurate and reliable. Six kinds of liquid with different physical properties were chosen as the research object. The numerical results were analyzed and compared. Finally, the effect of the surface tension, viscosity and density on the droplet ejection process was discussed.

Sign in / Sign up

Export Citation Format

Share Document