Lattice Boltzmann simulation of convective flow and heat transfer in a nanofluid-filled hollow cavity

Abstract

Purpose This paper aims to to simulate the flow and heat transfer during free convection in a square cavity using double-multi-relaxation time (MRT) lattice Boltzmann method. Design/methodology/approach The double-MRT lattice Boltzmann method is used, and the natural convection fluid flow and heat transfer under influence of different parameters are analyzed. The D2Q5 model and D2Q9 model are used for simulation of temperature field and flow field, respectively. The cavity is filled with CuO-water nanofluid; in addition, the thermo-physical properties of nanofluid and the effect of nanoparticles’ shapes are considered using Koo–Kleinstreuer–Li (KKL) model. On the other hand, the cavity is included with an internal active hollow with constant thermal boundary conditions at its walls and variable dimensions. It should be noted that the dimensions of the internal hollow will be determined by as aspect ratio. Findings The Rayleigh number, nanoparticle concentration and the aspect ratio are the governing parameters. The heat transfer performance of the cavity has direct relationship with the Rayleigh number and solid volume fraction of CuO-water nanofluid. Moreover, the configuration of the cavity is good controlling factor for changing the heat transfer performance and entropy generation. Originality/value The originality of this work is using double-MRT lattice Boltzmann method in simulating the free convection fluid flow and heat transfer.

Simulation of phase change during the freezing of unsaturated porous media by using a coupled lattice Boltzmann model

“…However, as human exploration advances, more scenarios for heat transfer research are being developed, and microscopic structures such as porous media are one of the particularly significant ones (Lewis et al , 1996). Multiphase transition phenomena in porous media are widely found in nature and industrial applications, such as natural gas–oil hydrate development in the ocean (Zhang et al , 2022a), fluid with natural convection (Ashouri et al , 2021; Pu et al , 2019), food processing, treatment of pollutants, application of fuel cell (Liu and Wu, 2016; He et al , 2009) and so on (Imani and Mozafari-Shamsi, 2022). Comprehending the process of liquid–gas phase transition within porous structures is pivotal for elucidating natural phenomena and enhancing industrial processes.…”