Simulation of Flow Past a Square Cylinder by Parallel Lattice Boltzmann Method using Multi-Relaxation-Time Scheme

2006 ◽  
Vol 22 (1) ◽  
pp. 35-42 ◽  
Author(s):  
J.-S. Wu ◽  
Y.-L. Shao
Keyword(s):  
Relaxation Time ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Reynolds Numbers ◽  
Numerical Results ◽  
Channel Height ◽  
Blockage Ratio ◽  
Square Cylinder ◽  
Single Relaxation Time ◽  
Boltzmann Method

AbstractThe flows past a square cylinder in a channel are simulated using the multi-relaxation-time (MRT) model in the parallel lattice Boltzmann BGK method (LBGK). Reynolds numbers of the flow are in the range of 100 ∼ 1,850 with blockage ratio, 1/6, of cylinder height to channel height, in which the single-relaxation-time (SRT) scheme is not able to converge at higher Reynolds numbers. Computed results are compared with those obtained using the SRT scheme where it can converge. In addition, computed Strouhal numbers compare reasonably well with the numerical results of Davis (1984).

Reassessing the single relaxation time Lattice Boltzmann method for the simulation of Darcy’s flows

2016 ◽  
Vol 27 (04) ◽  
pp. 1650037 ◽  
Author(s):  
Pietro Prestininzi ◽  
Andrea Montessori ◽  
Michele La Rocca ◽  
Sauro Succi
Keyword(s):  
Porous Media ◽  
Relaxation Time ◽  
Lattice Boltzmann Method ◽  
Knudsen Number ◽  
Lattice Boltzmann ◽  
Physical Dependence ◽  
Single Relaxation Time ◽  
Flows In Porous Media ◽  
Percent Accuracy ◽  
Boltzmann Method

It is shown that the single relaxation time (SRT) version of the Lattice Boltzmann (LB) equation permits to compute the permeability of Darcy’s flows in porous media within a few percent accuracy. This stands in contrast with previous claims of inaccuracy, which we relate to the lack of recognition of the physical dependence of the permeability on the Knudsen number.

Numerical analysis of blockage effects on the flow between parallel plates by using Lattice Boltzmann method

2020 ◽  
Author(s):  
S.U. Islam ◽  
Naqib Ullah ◽  
Chao Ying Zhou
Keyword(s):  
Numerical Analysis ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Results ◽  
Computational Domain ◽  
Blockage Ratio ◽  
Two Dimensional ◽  
Parallel Plates ◽  
Single Cylinder ◽  
Boltzmann Method

In this study the two-dimensional flow over a square cylinder placed in a parallel plates is simulated numerically by using lattice Boltzmann method (LBM) at low Reynolds numbers. Both the plates are obstructed by solid rectangular blocks of variable length. The fluid was allowed to flow in a parallel plates for Reynolds number (Re) from 75 to 150, and blockage ratio (g*) ranges from 1 to 3. The numerical investigation does not simply yield the predictable primary region of recirculating flow connected to the obstructions, it also shows supplementary regions of the flow downstream of the single cylinder placed in a computational domain. These supplementary separation zones were not already described in the research. The numerical analysis shows that the downstream flow of obstructions and single cylinder remained two dimensional for Re varied from75 to 150. Results available in previous research, are reported and compared with both of the available experimental and numerical results for code validation with single cylinder. Furthermore the effects of various Re and blockage ratio on the lift forces and drag coefficient is analyzed. Under these circumstances, good agreement between experimental and numerical results are obtained. The hydrodynamic forces of the cylinder are strongly influenced by the spacing ratios.

Lattice Boltzmann Method Used to Simulate an Unsteady Flow Around an Obstacle in Laminar Regime

2011 ◽  
Author(s):  
Wafik Abassi ◽  
Fethi Aloui ◽  
Sassi Ben Nasrallah ◽  
Jack Legrand
Keyword(s):  
Unsteady Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Flow Behavior ◽  
Reynolds Numbers ◽  
Numerical Results ◽  
Laminar Regime ◽  
Boltzmann Method ◽  
3D Problem

This work deals with the application of the lattice Boltzmann method to simulate the unsteady laminar flow around a confined square obstacle. For this configuration, we can observe some regimes that fluid may occur during its flowing. We have determined numerically the flow behavior for linear and stable regime. The variable aspect of the flow observed depends on the Reynolds number. In this study, we determine the velocity fields for a various Reynolds numbers by resolving the Navier-Stokes equations using the Lattice Boltzmann Method with BGK schema. This method is a recent extension of the LB method which demonstrated its potential for describing incompressible flow around an obstacle. A numerical study of 2D and 3D problem around a square obstacle using the Lattice Boltzmann Method with BGK schema is presented for an unsteady flow in laminar regime. The flow behavior in a horizontal channel with a rectangular cross-section, where a squared obstacle is placed in the middle, is discussed. In the 2D simulation, the obtained numerical results show a good agreement with experimental results [18]. Then we extend the ability of this method to solve the 3D problem. Numerical results behind the obstacle, obtained for various Reynolds numbers, are also analyzed and discussed.

On the inclusion of mass source terms in a single-relaxation-time lattice Boltzmann method

2018 ◽  
Vol 30 (5) ◽  
pp. 057104 ◽  
Author(s):  
Olav Aursjø ◽  
Espen Jettestuen ◽  
Jan Ludvig Vinningland ◽  
Aksel Hiorth
Keyword(s):  
Relaxation Time ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Source Terms ◽  
Mass Source ◽  
Single Relaxation Time ◽  
Boltzmann Method

Stability Condition for Single-Relaxation Time Isothermal Lattice Boltzmann Formulation

2014 ◽  
Vol 695 ◽  
pp. 667-670
Author(s):  
Nor Azwadi Che Sidik ◽  
Siti Aisyah Razali
Keyword(s):  
Reynolds Number ◽  
Relaxation Time ◽  
Lattice Boltzmann Method ◽  
Stability Condition ◽  
Lattice Boltzmann ◽  
Mesh Size ◽  
Single Relaxation Time ◽  
The Stability ◽  
Boltzmann Method

In this present research, the Lattice Boltzmann method has been used to determine the stability condition of the single relaxation time. The range of Reynolds number is 100,400 and 1000. Meanwhile, the range of mesh size is varying between 31 to 251. The results show that the increase in both mesh size and Reynolds number give an effect on deviation percentages. The deviation percentages for all mesh and Reynolds number also presented.

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