Comparative Study of the Flow in a Differentially Heated Cavity Using Thermal Lattice Boltzmann Method

2013 ◽  
Vol 300-301 ◽  
pp. 1122-1126
Author(s):  
Wei Shan Chen ◽  
Di Bo Dong ◽  
Zhen Xiu Hou ◽  
Sheng Jun Shi

A D2Q9 thermal lattice Boltzmann model is applied to investigate the flow in a differentially heated cavity. The paper is intended to analysis the physics of heat and mass transfer in a closure cavity filled with air. For three Rayleigh numbers Ra, the aspect ratio K are varied from 1 to 10. Results of validation indicate this algorithm is reliable and easy for implementation. It can be found that the circulation rate of heat driven flow get lower when the K get higher. Also, the Nusselt number Nu tends to be approximated to 1 when K is higher than a critical value, which is depended on the value of Ra.

2014 ◽  
Vol 668-669 ◽  
pp. 326-330
Author(s):  
Guang Zhao

In this paper, numerical simulation of natural convection in a closure square cavity with heating source on the basement is carried out using thermal lattice Boltzmann method. The purpose of this work is to analysis the physics of mass and heat transfer in such a condition. For different Rayleigh numbers, the relative heating area ratio is changed in the range of 0.1-1.0, correspondingly. It is found that the flow pattern is symmetrical for increases from 103to 106, and the boundary layers at low temperature become thinner, also the circulation rate is higher. For a special Rayleigh number, is as a monotone increment function of relative heating area ratio, and the value of which almost increases linearly when the area is below 0.8, and then reach to its maximum exponentially.


2014 ◽  
Vol 25 (02) ◽  
pp. 1350086 ◽  
Author(s):  
AHAD ZARGHAMI ◽  
SILVIA DI FRANCESCO ◽  
CHIARA BISCARINI

In this paper, fluid flows with enhanced heat transfer in porous channels are investigated through a stable finite volume (FV) formulation of the thermal lattice Boltzmann method (LBM). Temperature field is tracked through a double distribution function (DDF) model, while the porous media is modeled using Brinkman–Forchheimer assumptions. The method is tested against flows in channels partially filled with porous media and parametric studies are conducted to evaluate the effects of various parameters, highlighting their influence on the thermo-hydrodynamic behavior.


2021 ◽  
Vol 2097 (1) ◽  
pp. 012024
Author(s):  
Jianhu Wang ◽  
Zhongdi Duan ◽  
Cheng Cheng ◽  
Wenyong Tang

Abstract An adsorption model for fluid flow, heat, and mass transfer of the adsorbent bed was established. Based on the single relaxation time lattice Boltzmann method, a dual-distributed lattice Boltzmann model of density and concentration was established to solve the fluid flow and mass transfer process in the surface area of the adsorbent bed. The adsorption and heat transfer process on the surface of the adsorbent bed was incorporated into the dual-distributed lattice Boltzmann model by the fourth-order Runge-Kutta finite difference method. The multiphysics fields under Poiseuille flow were simulated by the presented model, and the adsorption capacity and temperature distribution during the adsorption process were investigated.


2021 ◽  
Vol 406 ◽  
pp. 164-169
Author(s):  
Zine Elabidine Bouayed ◽  
Samir Houat

We present in this work a numerical study of a ventilation system in a room with two openings in the ceiling and a floor heating indicated by constant heat temperature. The double population thermal lattice Boltzmann method is used, with nine velocities model D2Q9 for the dynamic field and a five velocities model D2Q5 for the temperature field. The results are presented in the form of streamlines, temperature contour and velocity profile, and analysed as a function of the Richardson number.


2012 ◽  
Vol 229-231 ◽  
pp. 282-286
Author(s):  
Mojtaba Aghajani Delavar

In this study a two dimensional thermal Lattice Boltzmann model with nine velocities was used to study the flow pattern and thermal field inside a T-micromixer with a porous block. The effects of porosity of porous block and flow Reynolds number were investigated. The results showed that better mixing between hot and cold flows and more heat transfer to horizontal walls in contact with porous block in lower porosities; due to the fact that in lower porosities the effective thermal conductivity of porous block increases. In lower porosities due to higher mixing rates and thermal gradient the entropy generation will increase. According to results it was observed that model with lowest porosity has the maximum mixing rate between two entering hot and cold flows and maximum dimensionless entropy generation.


2013 ◽  
Vol 765-767 ◽  
pp. 460-464
Author(s):  
Shou Guang Yao ◽  
Gong Li Wang ◽  
Qing Fang Cheng ◽  
Chang Jiang Zhou

This paper established the thermal Lattice Boltzmann model of fluid flow and heat transfer, which is based on double lattice Boltzmann distribution model [. The temperature distribution adopted the higher accuracy velocity model. Based on this thermal lattice Boltzmann model, this paper simulated forced convection of circular tube fluid. Comparing the simulation results with the traditional CFD calculation results, we could find that the thermal lattice Boltzmann method have unique advantages in effectiveness and flexibility than the traditional calculation method.


Author(s):  
Minglei Shan ◽  
Yu Yang ◽  
Hao Peng ◽  
Qingbang Han ◽  
Changping Zhu

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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