Simulating natural convection and entropy generation of a nanofluid in an inclined enclosure under an angled magnetic field with a circular fin and radiation effect

2019 ◽  
Vol 139 (6) ◽  
pp. 3803-3816 ◽  
Author(s):  
Rui Zhang ◽  
Ali Ghasemi ◽  
Azeez A. Barzinjy ◽  
Maliheh Zareei ◽  
Samir M. Hamad ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Entropy Generation ◽  
Radiation Effect ◽  
Inclined Enclosure

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

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Amin Kardgar
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Entropy Generation ◽  
Wall Thickness ◽  
Conjugate Heat Transfer ◽  
Volume Fraction ◽  
Content Type ◽  
Inclined Enclosure

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.

Natural convection and entropy generation of a nanofluid in two connected inclined triangular enclosures under magnetic field effects

2019 ◽  
Vol 108 ◽  
pp. 104309 ◽  
Author(s):  
Wi Liu ◽  
Amin Shahsavar ◽  
Azeez A. Barzinjy ◽  
Abdullah A.A.A. Al-Rashed ◽  
Masoud Afrand
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Entropy Generation ◽  
Magnetic Field Effects ◽  
Field Effects

A Differential Quadrature Solution of MHD Natural Convection in an Inclined Enclosure With a Partition

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Kamil Kahveci ◽  
Semiha Öztuna
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Inclination Angle ◽  
Hartmann Number ◽  
Differential Quadrature ◽  
Flow And Heat Transfer ◽  
Inclined Enclosure ◽  
Vorticity Generation

Magnetohydrodynamics natural convection in an inclined enclosure with a partition is studied numerically using a differential quadrature method. Governing equations for the fluid flow and heat transfer are solved for the Rayleigh number varying from 104 to 106, the Prandtl numbers (0.1, 1, and 10), four different Hartmann numbers (0, 25, 50, and 100), the inclination angle ranging from 0degto90deg, and the magnetic field with the x and y directions. The results show that the convective flow weakens considerably with increasing magnetic field strength, and the x-directional magnetic field is more effective in reducing the convection intensity. As the inclination angle increases, multicellular flows begin to develop on both sides of the enclosure for higher values of the Hartmann number if the enclosure is under the x-directional magnetic field. The vorticity generation intensity increases with increase of Rayleigh number. On the other hand, increasing Hartmann number has a negative effect on vorticity generation. With an increase in the inclination angle, the intensity of vorticity generation is observed to shift to top left corners and bottom right corners. Vorticity generation loops in each region of enclosure form due to multicelluar flow for an x-directional magnetic field when the inclination angle is increased further. In addition, depending on the boundary layer developed, the vorticity value on the hot wall increases first sharply with increasing y and then begins to decrease gradually. For the high Rayleigh numbers, the average Nusselt number shows an increasing trend as the inclination angle increases and a peak value is detected. Beyond the peak point, the foregoing trend reverses to decrease with the further increase of the inclination angle. The results also show that the Prandtl number has only a marginal effect on the flow and heat transfer.

Numerical investigation of natural convection in an inclined enclosure filled with porous medium under magnetic field

2007 ◽  
Vol 50 (17-18) ◽  
pp. 3684-3689 ◽  
Author(s):  
Q.W. Wang ◽  
M. Zeng ◽  
Z.P. Huang ◽  
G. Wang ◽  
H. Ozoe
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Natural Convection ◽  
Numerical Investigation ◽  
Inclined Enclosure
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