Magneto hydrodynamic convection in a nanofluid saturated enclosure with porous fins

Abstract

<jats:sec> <jats:title content-type="abstract-subheading">Purpose</jats:title> <jats:p>This paper aims to numerically investigate the magnetohydrodynamic (MHD) convection heat transfer of nanofluid inside a differentially heated enclosure with various fin morphologies.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Design/methodology/approach</jats:title> <jats:p>The fluid flow within the cavity was governed by N-S equations while it within porous medium was solved by the non-Darcy model, called the Darcy–Forchheimer model based on representative element-averaging method. Empirical correlations from experimental data are used to evaluate the effective thermal conductivity and dynamic viscosity. Relevant governing parameters, including thermal Rayleigh number (10<jats:sup>5</jats:sup>-10<jats:sup>7</jats:sup>), Hartmann number (0-50), Darcy number (10<jats:sup>−6</jats:sup>-10<jats:sup>−1</jats:sup>), thermal conductivity ratio of porous matrix (1-10<jats:sup>3</jats:sup>), nanoparticles volume fraction (0-0.04) and topology designs of porous fins, are sensitively varied to identify their effects and roles on the fluid flow and heat transfer. Particularly, heatlines are used to investigate the mechanism of heat transport.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Findings</jats:title> <jats:p>Numerical results demonstrate that the predictions of average Nusselt number are augmented by using more porous fins with high permeability, and this effect becomes opposite in tiny Darcy numbers. Particularly, for high Darcy and Rayleigh numbers, the shortest fins could achieve the best performance of heat transfer. In addition, the prediction of average Nusselt number reduces with an increase in Hartmann numbers. An optimal nanoparticles concentration also exists to maximize heat transfer enhancement. Finally, numerical correlations for the average Nusselt number were proposed as functions of these governing parameters.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Practical implications</jats:title> <jats:p>Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Social implications</jats:title> <jats:p>Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering. In addition, optimum thermal removals could enhance the lifetime of electronics, therefore reducing the cost of energy and materials.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Originality/value</jats:title> <jats:p>To the best knowledge of authors, there are not any studies considering the synergetic effects of porous fins on MHD convection of nanofluids. Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering.</jats:p> </jats:sec>

Radiation heat transfer within a solar system considering nanofluid flow inside the absorber tube

“…Wind, geothermal and solar energies can be used to obtain such goal. Wind and solar energy are the most alternatives among these sources of energy (Wang et al , 2019; Zhu et al , 2020). Linear fresnel reflector (LFR) is a solar collector reflecting the rays onto a constant receiver standing along and upper the reflectors.…”

“…They produced absorber fins with a carbon nanotubes device, and thicker fins can be installed in this system. Numerically, Wang et al (2019) analyzed the convection of nanomaterial in a heated container with different fin configuration. Their outcomes demonstrated that the estimation of mean Nu is increased by using more permeable fins with great permeability.…”

Thermo-hydraulic and entropy generation analysis for magnetohydrodynamic pressure driven flow of nanofluid through an asymmetric wavy channel

“…The efficient heat transfer enhancement techniques are the need of the hour for different practical applications such as solar collectors, process plants, textile and aerospace applications, processes involving polymeric composite manufacturing, etc Moharana, 2019a, Rashidi et al, 2019;Wang et al, 2019). The techniques used in reality for the purpose of transfer of heat are classified into two, namely active and passive methods (Mereu et al, 2013;Rashidi et al, 2020).…”

“…The uses of corrugation in the wall (Mehta and Pati, 2018;Mousavi et al, 2020;Jaferian et al, 2019;Tiwari et al, 2017;Moharana, 2019b, 2019c), twisted tapes, ribs, baffles (Boruah et al, 2018;Boruah et al, 2019a) metallic porous media (Shamsabadi et al, 2019;Nebbali and Bouhadef, 2006;Bhowmick et al, 2020) and nanofluid (Rashidi et al, 2019;Boruah et al, 2019b;Darbari et al, 2020) are some of the passive heat transfer techniques for which external energy other than the pumping power is not needed. While the active techniques need external energy other than the pumping power to alter the flow field, and hence the heat transfer rate such as the application of electrical and magnetic fields (Rashid and Liang, 2020;Wang et al, 2019) for the flow of electrically conductive fluid.…”

Natural convection in an open ended nanofluid filled cavity with fins in the presence of partial magnetic field and thermal radiation

“…Their results report that the heat transfer increases with the increase in baffle length generally. Wang et al 25 studied the effect of horizontally applied uniform magnetic field on natural convection of CuO-water nanofluid in a square cavity in the presence of porous fins in different locations. They found that in case of large Darcy number and thermal conductivity ratio, the usage of more porous fins causes heat transfer rate to increase.…”