Lattice-Boltzmann Simulations of Complex Fluids

1997 ◽  
Vol 08 (04) ◽  
pp. 783-792 ◽  
Author(s):  
G. Gonnella ◽  
E. Orlandini ◽  
J. M. Yeomans
Keyword(s):  
Free Energy ◽  
Fluid Flow ◽  
Phase Separation ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Positive Curvature ◽  
Navier Stokes ◽  
Two Phase ◽  
Lattice Boltzmann Simulation ◽  
Lattice Boltzmann Simulations

We show that by including thermodynamic functions derived from a chosen free energy in a lattice-Boltzmann simulation of fluid flow it is possible to ensure that the fluid relaxes to a well-defined equlilibrium corresponding to the minimum of the input free energy. Two examples are given of phase separation in a binary fluid: bulk two-phase coexistence and a lamellar phase stabilised by a competition between negative surface tension and positive curvature energy. The lattice-Boltzmann framework simulates the Navier–Stokes equations of fluid flow and hence allows investigation of the effects of hydrodynamics on the kinetics of phase separation and on the rheology of the ordered structures.

Lattice-Boltzmann Simulation of Two-Phase Fluid Flows

1998 ◽  
Vol 09 (08) ◽  
pp. 1383-1391 ◽  
Author(s):  
Yu Chen ◽  
Shulong Teng ◽  
Takauki Shukuwa ◽  
Hirotada Ohashi
Keyword(s):  
Lattice Boltzmann ◽  
Fluid Flows ◽  
Navier Stokes ◽  
Interface Model ◽  
Two Phase ◽  
Navier Stokes Equation ◽  
Lattice Boltzmann Simulation ◽  
Dam Breaking ◽  
Volumetric Stress ◽  
Phase Fluid

A model with a volumetric stress tensor added to the Navier–Stokes Equation is used to study two-phase fluid flows. The implementation of such an interface model into the lattice-Boltzmann equation is derived from the continuous Boltzmann BGK equation with an external force term, by using the discrete coordinate method. Numerical simulations are carried out for phase separation and "dam breaking" phenomena.

scholarly journals Hydrodynamic forces on steady and oscillating porous particles

2012 ◽  
Vol 709 ◽  
pp. 123-148 ◽  
Author(s):  
Santtu T. T. Ollila ◽  
Tapio Ala-Nissila ◽  
Colin Denniston
Keyword(s):  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Hydrodynamic Force ◽  
Navier Stokes ◽  
Uniform Density ◽  
Local Velocity ◽  
Velocity Difference ◽  
Navier Stokes Equations ◽  
Analytical Results ◽  
Lattice Boltzmann Simulations

AbstractWe derive new analytical results for the hydrodynamic force exerted on a sinusoidally oscillating porous shell and a sphere of uniform density in the Stokes limit. The coupling between the spherical particle and the solvent is done using the Debye–Bueche–Brinkman (DBB) model, i.e. by a frictional force proportional to the local velocity difference between the permeable particle and the solvent. We compare our analytical results and existing dynamic theories to lattice–Boltzmann simulations of the full Navier–Stokes equations for the oscillating porous particle. We find our analytical results to agree with simulations over a broad range of porosities and frequencies.

scholarly journals ENTROPIC LATTICE BOLTZMANN SIMULATION OF THE FLOW PAST SQUARE CYLINDER

2004 ◽  
Vol 15 (03) ◽  
pp. 435-445 ◽  
Author(s):  
SANTOSH ANSUMALI ◽  
SHYAM SUNDER CHIKATAMARLA ◽  
CHRISTOS EMMANOUIL FROUZAKIS ◽  
KONSTANTINOS BOULOUCHOS
Keyword(s):  
Reynolds Number ◽  
Lattice Boltzmann ◽  
Large Scale ◽  
Stokes Equations ◽  
Coarse Grained ◽  
Navier Stokes ◽  
Square Cylinder ◽  
Flow Past ◽  
Lattice Boltzmann Simulation ◽  
Decaying Turbulence

Minimal Boltzmann kinetic models, such as lattice Boltzmann, are often used as an alternative to the discretization of the Navier–Stokes equations for hydrodynamic simulations. Recently, it was argued that modeling sub-grid scale phenomena at the kinetic level might provide an efficient tool for large scale simulations. Indeed, a particular variant of this approach, known as the entropic lattice Boltzmann method (ELBM), has shown that an efficient coarse-grained simulation of decaying turbulence is possible using these approaches. The present work investigates the efficiency of the entropic lattice Boltzmann in describing flows of engineering interest. In order to do so, we have chosen the flow past a square cylinder, which is a simple model of such flows. We will show that ELBM can quantitatively capture the variation of vortex shedding frequency as a function of Reynolds number in the low as well as the high Reynolds number regime, without any need for explicit sub-grid scale modeling. This extends the previous studies for this set-up, where experimental behavior ranging from Re ~O(10) to Re ≤1000 was predicted by a single simulation algorithm.1–5

A Coupled Approach for Fluid Dynamic Problems Using the PDE Framework Peano

2012 ◽  
Vol 12 (1) ◽  
pp. 65-84 ◽  
Author(s):  
Philipp Neumann ◽  
Hans-Joachim Bungartz ◽  
Miriam Mehl ◽  
Tobias Neckel ◽  
Tobias Weinzierl
Keyword(s):  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Fluid Dynamic ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Flow Models ◽  
Lattice Boltzmann Simulations ◽  
Improved Stability ◽  
Coupling Strategy ◽  
Pde Framework

AbstractWe couple different flow models, i.e. a finite element solver for the Navier-Stokes equations and a Lattice Boltzmann automaton, using the framework Peano as a common base. The new coupling strategy between the meso- and macroscopic solver is presented and validated in a 2D channel flow scenario. The results are in good agreement with theory and results obtained in similar works by Latt et al. In addition, the test scenarios show an improved stability of the coupled method compared to pure Lattice Boltzmann simulations.

Lattice Boltzmann simulations of droplet dynamics in two-phase separation with temperature field

2020 ◽  
Vol 32 (7) ◽  
pp. 073312 ◽  
Author(s):  
Ningguang Chen ◽  
Zunlong Jin ◽  
Yonghao Liu ◽  
Peng Wang ◽  
Xiaotang Chen
Keyword(s):  
Temperature Field ◽  
Phase Separation ◽  
Lattice Boltzmann ◽  
Two Phase ◽  
Droplet Dynamics ◽  
Lattice Boltzmann Simulations

Numerical Prediction of Natural Convection Heat Transfer through Porous Media by the Lattice Boltzmann Method

2011 ◽  
Vol 110-116 ◽  
pp. 4439-4444
Author(s):  
Irwan Mohd Azmi Mohd ◽  
Nor C. Sidik Azwadi
Keyword(s):  
Fluid Flow ◽  
Rayleigh Number ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Flow Behavior ◽  
Convection Heat Transfer ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Medium Porosity ◽  
Thermal Fluid Flow

In this paper, we report an efficient numerical method to predict thermal fluid flow behavior in a square cavity filled with porous medium. The conventional Navier-Stokes equations are solved indirectly, i.e by the lattice Boltzmann formulation with second order accuracy in space and time. Numerical experiments were performed with different values of medium porosity and Rayleigh number to investigate the effect of these dimensionless parameters on the thermal fluid flow behavior in the cavity. In the current study, we found that the dynamics and the structure of primary vortex are significantly affected by the Rayleigh number and the medium porosity.

scholarly journals Modeling of Grouting Penetration in Porous Medium with Influence of Grain Distribution and Grout–Water Interaction

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 77
Author(s):  
Mengmeng Zhou ◽  
Fengshuai Fan ◽  
Zhuo Zheng ◽  
Chenyang Ma
Keyword(s):  
Grain Size ◽  
Porous Medium ◽  
Fluid Flow ◽  
Analytical Solution ◽  
Stokes Equations ◽  
Linear Trend ◽  
Injection Pressure ◽  
Navier Stokes ◽  
Two Phase ◽  
Grain Distribution

In this study, a numerical model of grouting penetration in a porous medium is established. The fluid flow in the interstices of the porous medium is directly modeled by Navier–Stokes equations. The grouting process is considered as a two-phase flow problem, and the level set method is used to characterize the interaction between grout and groundwater. The proposed model has considered the nuances for each grain during grouting penetration, instead of representing the fluid flow as a continuum process. In the simulation, three kinds of porosity (0.3; 0.4; 0.5) and two kinds of grain size distribution (0.5~1 mm; 1~2 mm) are used. Results show that: the pressure drop along penetration distance is approximately in a linear trend. The variation of filling degree along grouting distance approximately obeys a quadratic polynomial function. The injection pressure is influenced by the porosity and grain size of the porous medium, especially by the former. A theoretical analysis is carried out to propose an analytical solution of the grouting penetration. The analytical solution gives a good estimation when the grain amounts in the porous medium are small, and the difference becomes larger as the grain amounts increase.

Lattice Boltzmann Simulation of Jet Breakup and Droplet Formation in Immiscible Liquid-Liquid System

2017 ◽  
Author(s):  
Shimpei Saito ◽  
Yutaka Abe ◽  
Akiko Kaneko ◽  
Yuzuru Iwasawa ◽  
Kazuya Koyama
Keyword(s):  
Lattice Boltzmann ◽  
Numerical Stability ◽  
Three Dimensional ◽  
Droplet Formation ◽  
Liquid System ◽  
Immiscible Liquid ◽  
Two Phase ◽  
Jet Breakup ◽  
Lattice Boltzmann Simulation ◽  
Lattice Boltzmann Simulations

It is essential to understand the fundamental processes between melt jet and coolant during a postulated core-disruptive accident of a sodium-cooled fast reactor. In the present study, jet breakup and droplet formation in immiscible liquid-liquid system were studied numerically. A lattice Boltzmann two-phase model was modified in framework of three-dimensional 27-lattice to enhance the numerical stability. This model was applied to the conditions of jet breakup simulations. The present lattice Boltzmann simulations qualitatively reproduced the characteristic transitions of breakup regimes.

Numerical Modeling of Evolution of Boundary Between Incompressible Gas and Liquid in Two-Dimensional Region

2006 ◽  
Vol 4 ◽  
pp. 224-236
Author(s):  
A.S. Topolnikov
Keyword(s):  
Numerical Modeling ◽  
Interphase Boundary ◽  
Incompressible Liquid ◽  
Stokes Equations ◽  
Numerical Code ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Incompressible Media ◽  
Good Agreement

The paper is devoted to numerical modeling of Navier–Stokes equations for incompressible media in the case, when there exist gas and liquid inside the rectangular calculation region, which are separated by interphase boundary. The set of equations for incompressible liquid accounting for viscous, gravitational and surface (capillary) forces is solved by finite-difference scheme on the spaced grid, for description of interphase boundary the ideology of Level Set Method is used. By developed numerical code the set of hydrodynamic problems is solved, which describe the motion of two-phase incompressible media with interphase boundary. As a result of numerical simulation the solutions are obtained, which are in good agreement with existing analytical and experimental solutions.

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