Lattice Boltzmann Method Based Simulation of Natural Convection in Partially Open Enclosure

2013 ◽  
Vol 44 (2) ◽  
pp. 154-171 ◽  
Author(s):  
B. Gera ◽  
R.K. Singh
Keyword(s):  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
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.

scholarly journals Lid-Driven Cavity For Mantle Convection Modelling Using Lattice Boltzmann Method

2021 ◽  
Vol 32 (1) ◽  
pp. 21-28
Author(s):  
Umar Fauzi
Keyword(s):  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Mantle Convection ◽  
Dimensional System ◽  
Kinetic Theory Of Gases ◽  
Driven Cavity ◽  
Two Dimensional System ◽  
Boltzmann Method ◽  
Simulation Systems

The Lattice Boltzmann Method is one of the computational fluid dynamics methods that can be applied to simulate fluid based on the microscopic and kinetic theory of gases. In this study, earth mantle convection is simulated by combining the concept of lid-driven cavity simulation and natural convection using the Lattice Boltzmann method in a two-dimensional system (D2Q9). The results of the lid-driven cavity and natural convection simulation are comparable to previous works. This study shows that at a certain lid velocity, the direction of the moving plume is changed. This earth mantle convection simulation will give better and more reliable results by considering more complicated boundary conditions and adequate simulation systems.

Natural convection heat transfer of nanofluid inside a cavity containing rough elements using lattice Boltzmann method

2019 ◽  
Vol 29 (10) ◽  
pp. 3659-3684 ◽  
Author(s):  
Rasul Mohebbi ◽  
Mohsen Izadi ◽  
Nor Azwadi Che Sidik ◽  
Gholamhassan Najafi
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Aspect Ratio ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Convection Heat ◽  
Nanofluid Flow ◽  
Content Type ◽  
Boltzmann Method

Purpose This paper aims to study the natural convection of a nanofluid inside a cavity which contains obstacles using lattice Boltzmann method (LBM). The results have focused mainly on various parameters such as number and aspect ratio of roughness elements and different nanoparticle volume fraction. The isotherms and streamlines are presented to describe the hydrodynamics and thermal behaviors of the nanofluid flow throughout the enclosure. Design/methodology/approach The methodology of this paper consists of mathematical model, statement of the problem, nanofluid thermophysical properties, lattice Boltzmann method, LBM for fluid flow, LBM for heat transfer, numerical strategy, boundary conditions, Nusselt (Nu) number calculation, code validation and grid independence. Findings Natural convection heat transfers of a nanofluid inside cavities with and without rough elements have been studied. Lattice Boltzmann technique has been used as numerical approach. The results showed that at higher Rayleigh number (Ra = 106), there are denser streamlines near the left (source) and right wall (sink) which results in better cooling and enhances convective heat rejection to the heat sink. After a distinctive aspect ratio of rough elements (A = 0.1), change in streamline pattern which arises from increasing of aspect ratio does not have an important effect on isotherms. Results indicate that for lower Rayleigh number (Ra = 103), no variation in average Nu is observed with increasing in number of roughness, while for higher one (Ra = 106) average Nu decreases from N = 0 (smooth cavity) up to N = 4 and then remains constant (N = 6). Originality/value Currently, no argumentative and comprehensive extraction can be concluded without fully understanding the role of different arrangement of roughness. Some geometrical parameters such as aspect ratio, number and position of rough elements have been considered. Also, the effect of nanoparticle concentration was studied at different Ra number. Briefly, using LBM, this paper aims to investigate the natural convection of a nanofluid flow on the thermal and hydrodynamics parameters in the presence of rough element with various arrangements.

Nanofluid flow and heat transfer due to natural convection in a semi-circle/ellipse annulus using modified lattice Boltzmann method

2019 ◽  
Vol 29 (12) ◽  
pp. 4746-4763 ◽  
Author(s):  
Qingang Xiong ◽  
Arash Khosravi ◽  
Narjes Nabipour ◽  
Mohammad Hossein Doranehgard ◽  
Aida Sabaghmoghadam ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Entropy Generation ◽  
Lattice Boltzmann ◽  
Temperature Fields ◽  
Shape Effect ◽  
Nanofluid Flow ◽  
Content Type ◽  
Boltzmann Method

Purpose This paper aims to numerically investigate the nanofluid flow, heat transfer and entropy generation during natural convection in an annulus. Design/methodology/approach The lattice Boltzmann method is used to simulate the velocity and temperature fields. Furthermore, some special modifications are applied to make the lattice Boltzmann method capable for simulation in the curved boundary conditions. The annulus is filled with CuO-water nanofluid. The dynamic viscosity of nanofluid is estimated using KLL (Koo-Kleinstreuer-Li) model, and the nanoparticle shape effect is taken account in calculating the thermal conductivity. On the other hand, the local/volumetric entropy generation is used to show the irreversibility under influence of different parameters. Findings The effect of considered governing parameters including Rayleigh number (103<Ra < 106); nanoparticle concentration (0<<0.04) and configuration of annulus on the flow structure; temperature field; and local and total entropy generation and heat transfer rate are presented. Originality/value The originality of this work is using of lattice Boltzmann method is simulation of natural convection in a curved configuration and using of Koo–Kleinstreuer–Li correlation for simulation of nanofluid.

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