A decoupled and stabilized lattice Boltzmann method for multiphase flow with large density ratio at high Reynolds and Weber numbers

2021 ◽  
Vol 426 ◽  
pp. 109933
Author(s):  
Yongyong Wu ◽  
Nan Gui ◽  
Xingtuan Yang ◽  
Jiyuan Tu ◽  
Shengyao Jiang
Keyword(s):  
Multiphase Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Density Ratio ◽  
Large Density ◽  
Large Density Ratio ◽  
High Reynolds ◽  
Boltzmann Method

Improvement of Two-Component Model of the Finite Difference Lattice Boltzmann Method for a Gas-Liquid Flow Simulation

2007 ◽  
Author(s):  
Shinsuke Tajiri ◽  
Michihisa Tsutahara ◽  
Long Wu
Keyword(s):  
Finite Difference ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Density Ratio ◽  
Flow Simulation ◽  
Surface Force ◽  
Large Density ◽  
Two Component ◽  
Large Density Ratio ◽  
Boltzmann Method

An Improved model of the finite difference lattice Boltzmann method which allows us to consider gas-liquid two component flows with a large density ratio like air-water flows was proposed. Simulations of the two component fluids which have a free interface and a large density ratio were demonstrated. The model which has compressibility of fluid and allows us to consider the pressure waves propagating in water like water hammers was presented. The basic idea is to decrease a density fluctuation by giving a large pressure gradient. The compressibility of liquid was controlled by choosing the bulk modulus. In order to simulate immiscible two fluids, the modulated diffusion scheme proposed by Latva-Kokko et al. was employed. The scheme is able to produce a smooth interface by allowing a certain amount of interface diffusion. The continuum surface force proposed by Brackbill et al. was employed as surface tension. A collapse of liquid column was calculated in order to confirm the relation between the inertia of liquid with a large density and the gravity, and the appropriate result was obtained.

Removal of Shape Deformation in the Free Energy Based Lattice Boltzmann Method for Large Density Ratio

2015 ◽  
Author(s):  
Jia-ming Gong ◽  
Nobuyuki Oshima ◽  
Yutaka Tabe
Keyword(s):  
Free Energy ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Water Droplet ◽  
Density Ratio ◽  
Shape Deformation ◽  
Staggered Grids ◽  
Gas Channel ◽  
Large Density Ratio ◽  
Boltzmann Method

The free energy based lattice Boltzmann method (LBM) for two-phase flow with large density ratio is used to simulate droplet dynamics in the polymer electrolyte fuel cell (PEFC). The shape deformation of a static water droplet in the gas channel occurred in the simulations was eliminated. In this LBM model, two types of staggered grids which respectively make use of the velocity components from the orthogonal and diagonal directions are blended to calculate the hydrodynamic pressure from the Poisson equation, with the successive over-relaxation method (SOR). It is found that the simulated water droplet shape is determined by both the blending factor of the two types of staggered grids and the radius length. The appropriate blending factor for each radius length is summarized to optimize the simulation. The dependence of shape deformation on the blending factor and the radius length is further validated while considering the wettability effect of the solid wall of the gas channel. It is proved that the summarized appropriate blending factors are still practical when the concept of equivalent radius length is adopted.

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