Numerical investigation of conjugate heat transfer and entropy generation of MHD natural convection of nanofluid in an inclined enclosure

Abstract

Purpose The purpose of this paper is to investigate conjugate heat transfer of natural convection and entropy generation of nanofluid in the presence of external magnetic field via numerical approach in an inclined square cavity enclosure. Design/methodology/approach Control volume finite volume method with collocated arrangement of grids was used for discretization of continuity, momentum, solid and fluid energy equations. Rhie and Chow interpolation technique was applied to avoid checkerboard problem in pressure field and the well-established SIMPLE algorithm was followed to deal with the pressure and velocity coupling. The cavity is filled with water and nanoparticles of the aluminum oxide (Al2O3). This study has been conducted for the certain pertinent parameters of the volume fraction of nanoparticle (φ = 0–0.08), the angle of inclination (ϴ = 0°–330°), the Ra number (Ra = 103–108), the solid to fluid conductivity ratio (ksf = 1–400), the Ha number (Ha = 0–80) and the wall thickness ratio (δ/L = 0–0.3). Findings The results indicate that averaged Nu number increases by approximately 9% by increasing volume fraction from 0.0 to 0.08. Nu increases with an increasing inclination angle to 40° and decreases abruptly in 90° because of the formation of two weaker vorticity with opposite circulation pattern intensifying the density of isotherm curves in a vertical direction. Nu increases sharply with increasing Ra more than 105. Nu also augments almost 67% by increasing ksf = 1 to ksf = 50 and remains constant by increasing ksf more than 50. Nu number reduction is almost 72% with a variation of wall thickness ratio from d/L = 0 to 0.3. Entropy generation because of fluid flow, magnetic field and heat transfer reduces linearly almost 30%, 19% and 16% by increasing volume fraction, respectively. With increasing ksf, entropy generation because of fluid flow, magnetic field and heat transfer increases asymptotically, but Bejan number decreases. Originality/value A brief review of conducted research studies in nanofluid flow and heat transfer reveals that the effect of wall thermal inertia was not investigated in MHD natural convection of nanofluids in an inclined enclosure. The aim of the present study is to analyze conjugate heat transfer in an inclined cavity filled with water and Al2O3.

Numerical simulation of entropy generation in thermo-magnetic convection in an inverted T-shaped porous enclosure under thermal radiation

“…The same authors have also explored the natural or double-diffusive phenomena in their research articles (Kumar et al , 2023b, 2021). Furthermore, several other researchers have also paid attention to studying the entropy generation in conventional physical domains (Shaker et al , 2022; Ishak et al , 2020; Tayebi and Chamkha, 2019; Kardgar, 2021; Hussain et al , 2018; Singh et al , 2015b; Alipanah et al , 2015; Das and Basak, 2017; Roşca et al , 2023).…”

Effect of solid obstacle and thermal conditions on convective flow and entropy generation of nanofluid filled in a cylindrical chamber

“…Vijaybabu (2020) performed computational study to address the hot porous object impact on natural convective phenomena and irreversibilities in a cavity and found that the minimum EG depends on the permeability of cylinder. Kardgar (2021) examined the impact of Lorentz force on conduction–convection flow, thermal dissipation and EG of nanofluid filled in an inclined cavity. The collective effects of Lorentz force, chemical reaction and heat generation on the energy transport along with EG in a doubly stratified porous geometry have been studied by Kumar et al (2022a, 2022b).…”

Improvement of the heat transfer quality by air cooling of three‐heated obstacles in a horizontal channel using the lattice Boltzmann method

“…Conjugate heat transfer in a horizontal channel with wall-mounted obstacles is considered an attractive research topic due to the progress of high-performance electronic equipment in several engineering and industrial fields, particularly the cooling of the electronics system and the heat exchangers using different cooling systems depending on the studied fluid such as airor water-cooling system, and nanofluids cooling, which are mainly employed for their improved thermal properties as coolants in heat transfer devices such as heat exchangers, electronic cooling plates and radiators… 1,2 Therefore, many researchers adopt different numerical methods to investigate this type of problem. [3][4][5][6][7][8] Roy al. 9 analyzed experimentally the heat transfer of an array of aluminum obstacles in a horizontal airflow duct.…”