Lattice Boltzmann simulation of transient natural convection of air in square cavity under a magnetic quadrupole field

Abstract

Purpose The purpose of this paper is to apply the lattice Boltzmann method (LBM) with multiple distribution functions model, to simulate transient natural convection of air in a two-dimensional square cavity in the presence of a magnetic quadrupole field, under non-gravitational as well as gravitational conditions. Design/methodology/approach The density-temperature double distribution functions and D2Q9 model of LBM for the momentum and temperature equations are currently employed. Detailed transient structures of the flow and isotherms at unsteady state are obtained and compared for a range of magnetic force numbers from 1 to 100. Characteristics of the natural convection at initial moment, quasi-steady state and steady state are presented in present work. Findings At initial time, effects of the magnetic field and gravity are both relatively limited, but the effects become efficient as time evolves. Bi-cellular flow structures are obtained under non-gravitational condition, while the flow presents a single vortex structure at first under gravitational condition, and then emerges a bi-cellular structure with the increase of magnetic field force number. The average Nusselt number generally increases with the augment of magnetic field intensity. Practical implications This paper will be useful in the researches on crystal material and protein growth, oxygen concentration sensor, enhancement or suppression of the heat transfer in micro-electronics and micro-processing technology, etc. Originality/value The current study extended the application of LBM on the transient natural convective problem of paramagnetic fluids in the presence of an inhomogeneous magnetic field.

Lattice Boltzmann simulation for natural convection of supercritical CO2 in an inclined square cavity

“…Natural convection exists widely in engineering fields, such as solar collectors, building insulation, insulating glass windows, heat dissipation of electronic components and heat dissipation from nuclear reactors. Because of the complicated mechanism and multiple influence factors, flow and heat transfer of natural convection in a closed cavity has gained the attention of researchers at home and abroad (Sun et al , 1983; Xie et al , 2016; Pichandi and Anbalagan, 2018; Górecki and Szumbarski, 2014).…”

SEM-based numerical framework for non-Darcy mixed convection in a porous cavity with three adiabatic thin baffles on the hot wall

“…Regarding the numerical algorithms, the PFEM, FDM and FVM mentioned above are all popular methods to simulate flow and heat transfer. Another relatively new algorithm applied for the convective heat transfer in porous media is the lattice Boltzmann method, based on the molecular theory (Gao et al , 2015; Xie et al , 2016). Therefore, numerical method is a significant tool to investigate the flow and heat transfer problems in porous media.…”

Lattice Boltzmann simulation of free convection in nanofluid filled cavity with partially active walls – entropy generation and heatline visualization

“…In the numerical simulations, different numerical methods are being used by the researchers. Among these numerical methods, the lattice Boltzmann numerical method is one of the most exact methods rendering accurate and reliable results, which is used by many researchers (Xie et al, 2016;Guo et al, 2010). Rahmati and Tahery (2017) performed a numerical work to investigate the natural convection heat transfer using lattice Boltzmann method in a TiO 2 -water nanofluid-filled cavity in the presence of internal hot obstacle.…”