scholarly journals Lattice Boltzmann simulation of two-sided lid-driven flow in deep cavities

2015 ◽  
pp. 157-168
Author(s):  
Natasa Lukic ◽  
Predrag Tekic ◽  
Jelena Radjenovic ◽  
Ivana Sijacki
Keyword(s):  
Aspect Ratio ◽  
Flow Pattern ◽  
Lattice Boltzmann ◽  
Reynolds Numbers ◽  
Critical Aspect ◽  
Symmetric Flow ◽  
Primary Vortex ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method ◽  
Deep Cavities

The present study is concerned with two-sided lid-driven incompressible flow in rectangular, deep cavities applying lattice Boltzmann method. After validating the code for the square cavity, solutions for cavities with an aspect ratio 1.5 and 4 were obtained for the Reynolds numbers of 100, 400, 1000 and 3200. The influence of the Reynolds number and aspect ratio on the flow pattern and on the characteristics of vortices inside the cavity was studied. Symmetric flow pattern was obtained for all investigated cases. The middle of the cavity is mostly influenced by the increase in the aspect ratio. Critical aspect ratio, at which the birth of a primary vortex in the middle of the cavity takes place, was determined to be between 2.7 and 2.725.

Lattice BGK Study on Flow Pattern in Two-Dimensional Wall-Driven Semi-Circular Cavity

2011 ◽  
Vol 354-355 ◽  
pp. 594-598
Author(s):  
Fan Yang ◽  
Lian Guo Liu ◽  
Xu Ming Shi ◽  
Xue Yan Guo
Keyword(s):  
Flow Pattern ◽  
Lattice Boltzmann ◽  
Reynolds Numbers ◽  
Central Line ◽  
Circular Cavity ◽  
Two Dimensional ◽  
Order Accuracy ◽  
Curved Boundary ◽  
Dimensionless Velocity ◽  
Boltzmann Method

The flow pattern in a two-dimensional wall-driven semi-circular cavity is analyzed using the lattice Boltzmann method (LBM). The treatment of curved boundary with second-order accuracy is used. The streamline contours as well as dimensionless velocity component along the central line of a semi-circular cavity are obtained for different Reynolds numbers. The numerical results show that the LBM can capture the formation of primary, secondary and tertiary vortices exactly as the Reynolds number increases and has a great agreement with those of current literatures.

scholarly journals Lattice Boltzmann simulation of flow over a circular cylinder at moderate Reynolds numbers

2014 ◽  
Vol 18 (4) ◽  
pp. 1235-1246 ◽  
Author(s):  
Perumal Arumuga ◽  
Gundavarapu Kumar ◽  
Anoop Dass
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Lattice Boltzmann ◽  
Reynolds Numbers ◽  
Channel Length ◽  
Incompressible Viscous Flow ◽  
Lattice Boltzmann Simulation ◽  
Flow Features ◽  
Boltzmann Method ◽  
Steady And Unsteady Flows

This work is concerned with Lattice Boltzmann computation of two-dimensional incompressible viscous flow past a circular cylinder confined in a channel. Computations are carried out both for steady and unsteady flows and the critical Reynolds number at which symmetry breaks and unsteadiness sets in is predicted. Effects of Reynolds number, blockage ratio and channel length are studied in some details. All the results compare quite well with those computed with continuum-based methods, demonstrating the ability and usefulness of the Lattice Boltzmann Method (LBM) in capturing the flow features of this interesting and fluid-mechanically rich problem.

Lattice Boltzmann simulation of fluid flow and heat transfer in a parallel-plate channel with transverse rectangular cavities

2017 ◽  
Vol 28 (03) ◽  
pp. 1750042 ◽  
Author(s):  
Rasul Mohebbi ◽  
Hanif Heidari
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Numerical Code ◽  
Nusselt Numbers ◽  
Flow And Heat Transfer ◽  
Lattice Boltzmann Simulation ◽  
Smooth Channel ◽  
Boltzmann Method

The aim of this paper is investigating the forced convection heat transfer in a channel with transverse rectangular cavities using the lattice Boltzmann method (LBM) which is not available in the literature yet. The effects of the Reynolds number (100–400), cavity aspect ratio ([Formula: see text], 0.5, 1.0), distance of cavities from each other ([Formula: see text]) in fixed depth of cavity ([Formula: see text]) on the velocity and temperature profiles are studied. Moreover, the flow patterns such as deflection and re-circulation zone inside the cavities are obtained. The local and averaged Nusselt numbers on the channel walls are achieved. The results show that the channel with cavities achieves heat transfer enhancements relative to the smooth channel. For the constant cavity aspect ratio, the maximum value of averaged Nusselt number in the channel is obtained in the case of [Formula: see text]. Heat transfer to the working fluids increases significantly by increasing the aspect ratio. The existed results are used to ascertain the validity of the numerical code and excellent agreement between results was found.

THERMAL LATTICE BOLTZMANN SIMULATION OF VISCOUS FLOW IN A SQUARE CAVITY

2005 ◽  
Vol 16 (06) ◽  
pp. 867-877 ◽  
Author(s):  
XIAO-YANG LÜ ◽  
CHAO-YING ZHANG ◽  
MU-REN LIU ◽  
LING-JIANG KONG ◽  
HUA-BING LI
Keyword(s):  
Lattice Boltzmann ◽  
Hexagonal Lattice ◽  
Reynolds Numbers ◽  
Square Cavity ◽  
Time Model ◽  
Thermal Fluids ◽  
Lattice Boltzmann Simulation ◽  
Wide Range ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann

The 13-speed thermal lattice Bhatnagar–Gross–Krook model on hexagonal lattice is a single relaxation time model with an adjustable parameter λ which makes the Prandtl number tunable. This model maintains the simplicity of the lattice Boltzmann method (LBM) and is also suitable for various thermal fluids. In this paper, it is applied to simulations of the lid-driven flow in a square cavity at a wide range of Reynolds numbers. Numerical experiments show that this model can give the same accurate results as those by the conventional numerical methods.

scholarly journals Lattice Boltzmann Simulation of Airflow and Mixed Convection in a General Ward of Hospital

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Taasnim Ahmed Himika ◽  
Md. Farhad Hasan ◽  
Md. Mamun Molla
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Lattice Boltzmann ◽  
Average Rate ◽  
Reynolds Numbers ◽  
General Ward ◽  
Convection Flow ◽  
Indoor Airflow ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method

In the present investigation the airflow and heat transfer for mixed convection have been simulated for a model general ward of hospital with six beds and partitions using the Lattice Boltzmann Method (LBM). Three different Reynolds numbers 100, 250, and 350 have been considered. Bounce-back condition has been applied at the wall. Results have been represented in three different case studies and the changes have been discussed in terms of streamlines and isotherms. Code validation has also been included before going through the simulation process and it shows good agreement with previously published papers when the comparison is made on average Nusselt number. Results show that the pattern of indoor airflow is varied in each and every case study due to the effect of mixed convection flow and placement of partition. In addition, the changes in average rate of heat transfer indicate that patients closer to inlet get the most air and feel better and if any patient does not need much air, he or she should be kept near the outlet to avoid temperature related complications.

Numerical Simulation for Flow over Two Circular Cylinders in Micro Channel with Lattice Boltzmann Method

2014 ◽  
Vol 670-671 ◽  
pp. 747-750
Author(s):  
Zhi Jun Gong ◽  
Jiao Yang ◽  
Wen Fei Wu
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Recirculation Zone ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Circular Cylinders ◽  
Micro Channel ◽  
Zone Length ◽  
Spacing Ratio ◽  
Boltzmann Method

For indepth study on flow characteristics for fluid bypass obstacles in micro-channel, the Lattice Boltzmann Method (LBM) was used to simulate fluid flow over two circular cylinders in side-by-side arrangement of a micro-channel. The velocity distribution and recirculation zone length under different Reynolds numbers (Re = 0~100) and different spacing ratio (H/D= 0~2.0) were obtained. The results show that the pattern of flow and the size of recirculation zone in the micro-channel depend on the combined effect of Re and H/D.

scholarly journals Lattice Boltzmann Simulation of Natural Convection in an Annulus between a Hexagonal Cylinder and a Square Enclosure

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
L. El Moutaouakil ◽  
Z. Zrikem ◽  
A. Abdelbaki
Keyword(s):  
Natural Convection ◽  
Rayleigh Number ◽  
Cross Section ◽  
Lattice Boltzmann ◽  
Square Enclosure ◽  
Lattice Boltzmann Simulation ◽  
Laminar Natural Convection ◽  
Heat Transfers ◽  
Boltzmann Method ◽  
Vertical Case

Laminar natural convection in a water filled square enclosure containing at its center a horizontal hexagonal cylinder is studied by the lattice Boltzmann method. The hexagonal cylinder is heated while the walls of the cavity are maintained at the same cold temperature. Two orientations are treated, corresponding to two opposite sides of the hexagonal cross-section which are horizontal (case I) or vertical (case II). For each case, the results are presented in terms of streamlines, isotherms, local and average convective heat transfers as a function of the dimensionless size of the hexagonal cylinder cross-section (0.1≤B≤0.4), and the Rayleigh number (103≤Ra≤106).

scholarly journals Lattice Boltzmann simulation of liquid falling on horizontal rectangular pillar arrays

2021 ◽  
Vol 321 ◽  
pp. 01014
Author(s):  
Makoto Sugimoto ◽  
Tatsuya Miyazaki ◽  
Zelin Li ◽  
Masayuki Kaneda ◽  
Kazuhiko Suga
Keyword(s):  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Flow Simulation ◽  
High Viscosity ◽  
Two Phase ◽  
Lattice Boltzmann Simulation ◽  
Pillar Arrays ◽  
Boltzmann Method ◽  
Behavior Characteristic

Stator coils of automobiles in operation generate heat and are cooled by a coolant poured from above. Since the behavior characteristic of the coolant poured on the coils is not clarified yet due to its complexity, the three-dimensional two-phase flow simulation is conducted. In this study, as a steppingstone to the simulation of the liquid falling on the actual coils, the coils are modelled with horizontal rectangular pillar arrays whose governing parameters can be easily changed. The two-phase flows are simulated using the lattice Boltzmann method and the phase-field model, and the effects of the governing parameters, such as the physical properties of the cooling liquid, the wettability, and the gap between the pillars, on the wetting area are investigated. The results show that the oil tends to spread across the pillars because of its high viscosity. Moreover, the liquid spreads quickly when the contact angle is small. In the case that the pillars are stacked, the wetting area of the inner pillars is larger than that of the exposed pillars.

Modeling of collapsing cavitation bubble near solid wall by 3D pseudopotential multi-relaxation-time lattice Boltzmann method

2017 ◽  
Vol 232 (3) ◽  
pp. 445-456 ◽  
Author(s):  
Minglei Shan ◽  
Yu Yang ◽  
Hao Peng ◽  
Qingbang Han ◽  
Changping Zhu
Keyword(s):  
Relaxation Time ◽  
Lattice Boltzmann ◽  
Cavitation Bubble ◽  
Solid Wall ◽  
Three Dimensional ◽  
Lattice Boltzmann Model ◽  
Bubble Collapse ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method ◽  
Boltzmann Model

Understanding the dynamic characteristic of the cavitation bubble near a solid wall is a fundamental issue for the bubble collapse application and prevention. In the present work, an improved three-dimensional multi-relaxation-time pseudopotential lattice Boltzmann model is adopted to investigate the cavitation bubble collapse near the solid wall. With respect to thermodynamic consistency, Laplace law verification, the three-dimensional pseudopotential multi-relaxation-time lattice Boltzmann model is investigated. By the theoretical analysis, it is proved that the model can be regarded as a solver of the Rayleigh–Plesset equation, and confirmed by comparing the results of the lattice Boltzmann simulation and the Rayleigh–Plesset equation calculation for the case of cavitation bubble collapse in the infinite medium field. The bubble collapse near the solid wall is modeled using the improved pseudopotential multi-relaxation-time lattice Boltzmann model. We find the lattice Boltzmann simulation and the experimental results have the same dynamic process by comparing the bubble profiles evolution. Form the pressure field and the velocity field evolution it is found that the tapered higher pressure region formed near the top of the bubble is a crucial driving force inducing the bubble collapse. This exploratory research demonstrates that the lattice Boltzmann method is an alternative tool for the study of the interaction between collapsing cavitation bubble and matter.

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