Characteristics of Flow past a Square Cylinder using the Lattice Boltzmann Method

2009 ◽  
Vol 8 (8) ◽  
pp. 1094-1114 ◽  
Author(s):  
S. Ul-Islam ◽  
C.Y. Zhou
2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
D. Arumuga Perumal ◽  
Gundavarapu V. S. Kumar ◽  
Anoop K. Dass

This work is concerned with the lattice Boltzmann computation of two-dimensional incompressible viscous flow past a square cylinder confined in a channel. It is known that the nature of the flow past cylindrical obstacles is very complex. In the present work, computations are carried out both for steady and unsteady flows using lattice Boltzmann method. Effects of Reynolds number, blockage ratio, and channel length are studied in detail. As good care has been taken to include appropriate measures in the computational method, these results enjoy good credibility. To sum up, the present study reveals many interesting features of square cylinder problem and demonstrates the capability of the lattice Boltzmann method to capture these features.


2018 ◽  
Vol 29 (04) ◽  
pp. 1850030 ◽  
Author(s):  
Yuan Ma ◽  
Rasul Mohebbi ◽  
M. M. Rashidi ◽  
Zhigang Yang

A numerical investigation is carried out to analyze the flow patterns, drag and lift coefficients, and vortex shedding around a square cylinder using a control circular bar upstream and downstream. Lattice Boltzmann method (LBM) was used to investigate flow over a square cylinder controlled by upstream and downstream circular bar, which is the main novelty of this study. Compared with those available results in the literature, the code for flow over a single square cylinder proves valid. The Reynolds number (Re) based on the width of the square cylinder ([Formula: see text]) and diameter of circular bar ([Formula: see text]) are 100 for square cylinder, 30 and 50 for different circular bars. Numerical simulations are performed in the ranges of [Formula: see text] and [Formula: see text], where [Formula: see text] and [Formula: see text] are the center-to-center distances between the bar and cylinder. Five distinct flow patterns are observed in the present study. It is found that the maximum percentage reduction in drag coefficient is 59.86% by upstream control bar, and the maximum percentage reduction in r.m.s. lift coefficient is 73.69% by downstream control bar. By varying the distance ratio for the downstream control bar, a critical value of distance ratio is found where there are two domain frequencies.


2006 ◽  
Vol 22 (1) ◽  
pp. 35-42 ◽  
Author(s):  
J.-S. Wu ◽  
Y.-L. Shao

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).


2011 ◽  
Vol 105-107 ◽  
pp. 2307-2310
Author(s):  
Jian Ping Yu ◽  
Shu Rong Yu ◽  
Xing Wang Liu

Lattice Boltzmann methods (LBM) have become an alternative to conventional computational fluid dynamics (CFD) methods for various systems. In this paper, flow field of mean flow past a circular cylinder was simulated based on the lattice Boltzmann method. The streamline of air past the cylinder illuminated that the fluid adhere on the boundary and doesn’t separate from the surface of cylinder when Re number less than 5. When Re number equal 40, flow separated to form a pair of recirculating eddies can be observed. With the Re number increasing, the trailing vortex length is growth accordingly. When Re number come up to 80, the trailing vortex begin to shed regularly. This result is consistent with the experiment data. Drag coefficient that fluid act on the surface of cylinder was calculated. The calculated results were same as the experiment data. Simulation indicate that LBM can simulate the vortex taking place and shedding effectively.


2017 ◽  
Vol 14 (01) ◽  
pp. 1750002 ◽  
Author(s):  
Yi-Kun Wei ◽  
Xu-Qu Hu

Two-dimensional simulations of channel flow past an array of cylinders are carried out at high Reynolds numbers. Considering the thickness fluctuating effect on the equation of motion, a modified lattice Boltzmann method (LBM) is proposed. Special attention is paid to investigate the thickness fluctuations and vortex shedding mechanisms between 11 cylinders. Results for the velocity and vorticity differences are provided, as well as for the energy density and enstrophy spectra. The numerical results coincide very well with some published experimental data that was obtained by turbulent soap films. The spectra extracted from the velocity and vorticity fields are displayed from simulations, along with the thickness fluctuation spectrum H(k). Our results show that the statistics of thickness fluctuations resemble closely those of a passive scalar in turbulent flows.


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