A non-equilibrium bounce-back boundary condition for thermal multispeed LBM

2021 ◽  
Vol 53 ◽  
pp. 101364
Author(s):  
Friedemann Klass ◽  
Alessandro Gabbana ◽  
Andreas Bartel
Keyword(s):  
Boundary Condition ◽  
Bounce Back ◽  
Non Equilibrium

Examination of the Slip Boundary Condition by µ-PIV and Lattice Boltzmann Simulations

2002 ◽  
Author(s):  
Derek C. Tretheway ◽  
Luoding Zhu ◽  
Linda Petzold ◽  
Carl D. Meinhart
Keyword(s):  
Boundary Condition ◽  
Shear Rate ◽  
Channel Flow ◽  
Lattice Boltzmann ◽  
Slip Velocity ◽  
Slip Length ◽  
Slip Boundary Condition ◽  
Slip Boundary ◽  
Lattice Boltzmann Simulations ◽  
Bounce Back

This work examines the slip boundary condition by Lattice Boltzmann simulations, addresses the validity of the Navier’s hypothesis that the slip velocity is proportional to the shear rate and compares the Lattice Boltzmann simulations to the experimental results of Tretheway and Meinhart (Phys. of Fluids, 14, L9–L12). The numerical simulation models the boundary condition as the probability, P, of a particle to bounce-back relative to the probability of specular reflection, 1−P. For channel flow, the numerically calculated velocity profiles are consistent with the experimental profiles for both the no-slip and slip cases. No-slip is obtained for a probability of 100% bounce-back, while a probability of 0.03 is required to generate a slip length and slip velocity consistent with the experimental results of Tretheway and Meinhart for a hydrophobic surface. The simulations indicate that for microchannel flow the slip length is nearly constant along the channel walls, while the slip velocity varies with wall position as a results of variations in shear rate. Thus, the resulting velocity profile in a channel flow is more complex than a simple combination of the no-slip solution and slip velocity as is the case for flow between two infinite parallel plates.

scholarly journals Efficient GPU implementation of the linearly interpolated bounce-back boundary condition

2013 ◽  
Vol 65 (6) ◽  
pp. 936-944 ◽  
Author(s):  
Christian Obrecht ◽  
Frédéric Kuznik ◽  
Bernard Tourancheau ◽  
Jean-Jacques Roux
Keyword(s):  
Boundary Condition ◽  
Gpu Implementation ◽  
Bounce Back

scholarly journals Mass-Conserved Wall Treatment of the Non-Equilibrium Extrapolation Boundary Condition in Lattice Boltzmann Method

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2585
Author(s):  
Zhe Feng ◽  
Hee-Chang Lim
Keyword(s):  
Boundary Condition ◽  
Distribution Function ◽  
Lattice Boltzmann ◽  
Treatment Method ◽  
Extrapolation Method ◽  
Equilibrium Distribution Function ◽  
Boundary Node ◽  
External Force Field ◽  
Mass Leakage ◽  
Non Equilibrium

In lattice Boltzmann simulations, the widely used non-equilibrium extrapolation method for velocity and pressure boundary conditions can cause a constant mass leakage under certain circumstances, particularly when an external force field is imposed on the fluid domain. The non-equilibrium distribution function at the boundary uses a first-order extrapolation method on the corresponding data of adjacent fluid nodes. In addition, based on this extrapolation method, the macroscopic velocity and density at the boundary nodes are obtained. Therefore, the corresponding equilibrium component of the distribution function can be calculated explicitly. Regarding the no-slip wall boundary condition, we found that the mass leakage primarily results from the extrapolation scheme for the density term in the equilibrium component of the distribution function at the boundary node. In this study, a mass-conserved wall treatment method is developed to correct the existing density term for guaranteeing the conservation of mass. Several benchmark test cases were simulated and compared to prove the justification of the newly developed mass-conserved boundary condition, and the results show a good agreement with those in the existing literature.

scholarly journals On anti bounce back boundary condition for lattice Boltzmann schemes

2020 ◽  
Vol 79 (3) ◽  
pp. 555-575 ◽  
Author(s):  
François Dubois ◽  
Pierre Lallemand ◽  
Mohamed Mahdi Tekitek
Keyword(s):  
Boundary Condition ◽  
Lattice Boltzmann ◽  
Bounce Back

scholarly journals Particle Flow Simulation Based on Hybrid IMB-DEM-LBM Approach with New Solid Fraction Calculation Scheme

2021 ◽  
Vol 11 (8) ◽  
pp. 3436
Author(s):  
Ri Zhang ◽  
Hyeong-Joo Kim ◽  
Peter Rey Dinoy
Keyword(s):  
Solid Fraction ◽  
Moving Boundary ◽  
Hydrodynamic Force ◽  
Flow Simulation ◽  
Grid Method ◽  
Particle Flow ◽  
Immersed Boundary ◽  
Force Calculation ◽  
Bounce Back ◽  
Non Equilibrium

A new coupling method, immersed moving boundary–discrete element method–lattice Boltzmann method (IMB-DEM-LBM), is proposed to simulate particle flow for application in soil mechanics or coastal engineering. In this study, LBM fluid is simulated on the regular Eulerian grid and Lagrangian particle motion is governed by DEM while IMB couples the two algorithms. The new method is promising and robust as it resolves numerical instability near the particle boundary caused by mesh distortion in the conventional grid method. In IMB, the interface lattice solid fraction determines the distribution function ratio of non-equilibrium bounce back and Bhatnagar-Gross-Krook (BGK) collision. The non-equilibrium bounce back at moving boundary results in the fluid momentum change and contributes to the hydrodynamic force on particle. For numerical stability, this paper introduces the hydrodynamic force calculation concept from IB (immersed boundary method) to IMB, and at the same time, proposes a new solid fraction calculation method for sphere that divides the intersection into simple sector and triangle, as well as calculates the intersection area by vector. With this method, approximate inaccuracy is overcome while complicated integration is avoided.

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