Multi Relaxation Time Lattice Boltzmann Method Simulation of Natural Convection Combined with Surface Radiation in a Square Open Cavity from Three Discrete Heat Sources

2020 ◽  
pp. 1-17
Author(s):  
Mustapha Ouahas ◽  
Abdelkhalek Amahmid ◽  
Mohammed Hasnaoui ◽  
Abdelfattah El Mansouri ◽  
Youssef Dahani
Keyword(s):  
Relaxation Time ◽  
Natural Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Open Cavity ◽  
Surface Radiation ◽  
Heat Sources ◽  
Discrete Heat Sources ◽  
Boltzmann Method

Investigation of Prandtl number effect on natural convection MHD in an open cavity by lattice Boltzmann method

2012 ◽  
Vol 30 (1) ◽  
pp. 97-116 ◽  
Author(s):  
GholamReza Kefayati ◽  
Mofid Gorji ◽  
Hasan Sajjadi ◽  
Davood Domiri Ganji
Keyword(s):  
Natural Convection ◽  
Prandtl Number ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Open Cavity ◽  
Boltzmann Method

Lattice Boltzmann Method for Combined Natural Convection Surface Radiation in Open Cavity

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Ayoub Msaddak ◽  
Mohieddine Ben Salah ◽  
Ezeddine Sediki
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Lattice Boltzmann Method ◽  
Inclination Angle ◽  
Lattice Boltzmann ◽  
Surface Radiation ◽  
Surface Emissivity ◽  
Boltzmann Method

Lattice Boltzmann method (LBM) is performed to study numerically combined natural convection and surface radiation inside an inclined two-dimensional open square cavity. The cavity is heated by a constant temperature at the wall facing the opening. The walls normal to the heated surface are assumed to be adiabatic, diffuse, gray, and opaque while the open boundary is assumed to be black at ambient temperature. A Bathnagar, Gross and Krook (BGK) collision model with double distribution function (D2Q9-D2Q4) is adopted. Effects of surface radiation, inclination angle, and Rayleigh number on the heat transfer are analyzed and discussed. Results are presented in terms of isotherms, streamlines, and Nusselt number. It was found that the presence of surface radiation enhances the heat transfer. The convective Nusselt number decreases with increasing surface emissivity as well as with Rayleigh number, while the total Nusselt number increases with increasing surface emissivity and Rayleigh number. The inclination angle has also a significant effect on flow and heat transfer inside the cavity. However, the magnitude of total heat transfer decreases considerably when open cavity is tilted downward.

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.

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