Simulation of natural convection flow in a square cavity by lattice-Boltzmann method within a wide range of Ra

2002 ◽  
Author(s):  
M. X. Li ◽  
Wen-Quan Tao ◽  
Qiu-Wang Wang ◽  
Ya-Ling He
Keyword(s):  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Convection Flow ◽  
Square Cavity ◽  
Natural Convection Flow ◽  
Wide Range ◽  
Boltzmann Method

scholarly journals A Multiple-Grid Lattice Boltzmann Method for Natural Convection under Low and High Prandtl Numbers

Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 148
Author(s):  
Seyed Amin Nabavizadeh ◽  
Himel Barua ◽  
Mohsen Eshraghi ◽  
Sergio D. Felicelli
Keyword(s):  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Large Scale ◽  
Bgk Model ◽  
Flow Equations ◽  
Wide Range ◽  
Prandtl Numbers ◽  
Boltzmann Method ◽  
Benchmark Solutions

A multi-distribution lattice Boltzmann Bhatnagar–Gross–Krook (BGK) model with a multiple-grid lattice Boltzmann (MGLB) model is proposed to efficiently simulate natural convection over a wide range of Prandtl numbers. In this method, different grid sizes and time steps for heat transfer and fluid flow equations are chosen. The model is validated against natural convection in a square cavity, since extensive benchmark solutions are available for that problem. The proposed method can resolve the computational difficulty in simulating problems with very different time scales, in particular, when using extremely low or high Prandtl numbers. The technique can also enhance computational speed and stability while keeping the simplicity of the BGK method. Compared with the conventional lattice Boltzmann method, the simulation time can be reduced up to one-tenth of the time while maintaining the accuracy in an acceptable range. The proposed model can be extended to other lattice Boltzmann collision models and three-dimensional cases, making it a great candidate for large-scale simulations.

SIMULATION OF NATURAL CONVECTION IN A SQUARE CAVITY BY TAYLOR SERIES EXPANSION- AND LEAST SQUARES-BASED LATTICE BOLTZMANN METHOD

2002 ◽  
Vol 13 (10) ◽  
pp. 1399-1414 ◽  
Author(s):  
C. SHU ◽  
Y. PENG ◽  
Y. T. CHEW
Keyword(s):  
Natural Convection ◽  
Least Squares ◽  
Lattice Boltzmann Method ◽  
Series Expansion ◽  
Taylor Series ◽  
Lattice Boltzmann ◽  
Taylor Series Expansion ◽  
Uniform Grid ◽  
Square Cavity ◽  
Boltzmann Method

The Taylor series expansion- and least squares-based lattice Boltzmann method (TLLBM) was used in this paper to extend the current thermal model to an arbitrary geometry so that it can be used to solve practical thermo-hydrodynamics in the incompressible limit. The new explicit method is based on the standard lattice Boltzmann method (LBM), Taylor series expansion and the least squares approach. The final formulation is an algebraic form and essentially has no limitation on the mesh structure and lattice model. Numerical simulations of natural convection in a square cavity on both uniform and nonuniform grids have been carried out. Favorable results were obtained and compared well with the benchmark data. It was found that, to get the same order of accuracy, the number of mesh points used on the nonuniform grid is much less than that used on the uniform grid.

Study of Adiabatic Obstacles on Natural Convection in a Square Cavity Using Lattice Boltzmann Method

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Pawan Karki ◽  
Ajay Kumar Yadav ◽  
D. Arumuga Perumal
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Transfer Rate ◽  
Square Cavity ◽  
Square Enclosure ◽  
The Core ◽  
Vertical Walls ◽  
Boltzmann Method

This study involves the effect of adiabatic obstacles on two-dimensional natural convection in a square enclosure using lattice Boltzmann method (LBM). The enclosure embodies square-shaped adiabatic obstacles with one, two, and four in number. The single obstacle in cavity is centrally placed, whereas for other two configurations, a different arrangement has been made such that the core fluid zone is not hampered. The four boundaries of the cavity considered here consist of two adiabatic horizontal walls and two differentially heated vertical walls. The current study covers the range of Rayleigh number (103 ≤ Ra ≤ 106) and a fixed Prandtl number of 0.71 for all cases. The effect of size of obstacle is studied in detail for single obstacle. It is found that the average heat transfer along the hot wall increases with the increase in size of obstacle until it reaches an optimum value and then with further increase in size, the heat transfer rate deteriorates. Study is carried out to delineate the comparison between the presences of obstacle in and out of the conduction dominant zone in the cavity. The number of obstacles (two and four) outside of this core zone shows that heat transfer decreases despite the obstacle being adiabatic in nature.

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