Entropy generation optimization for MHD natural convection of a nanofluid in porous media-filled enclosure with active parts and viscous dissipation

Abstract

Purpose This paper aims to investigate the entropy generation due to magnetohydrodynamic natural convection flow and heat transfer in a porous enclosure filled with Cu-water nanofluid in the presence of viscous dissipation effect. The left and right walls of the cavity are thermally insulated. There are heated and cold parts, and these are placed on the bottom and top wall, respectively, whereas the remaining parts are thermally insulated. Design/methodology/approach The finite volume method is used to solve the dimensionless partial differential equations governing the problem. A comparison with previously published woks is presented and is found to be in an excellent agreement. Findings The minimization of entropy generation and local heat transfer according to different values of the governing parameters are presented in details. It is found that the presence of magnetic field has negative effects on the local entropy generation because of heat transfer and the local total entropy generation. Also, the increase in the heated part length leads to a decrease in the local Nusselt number. Originality/value This problem is original, as it has not been considered previously.

Numerical investigation on natural convection of nanofluids in an inclined square enclosure with non-uniform heated walls

“…The water-based nano uid is idealized as a single-phase uid. Hence, the equations of physical parameters of nano uids are given as follows [33][34][35][36]. The e ective density of nano uid is m = (1 ) f + s ; the thermal di usivity of nano uid is m = m =(c p ) m , where (c p ) m is the heat capacitance of nano uid given by (c p ) m = (1 )(c p ) f + (c p ) s , and the thermal expansion coe cient of nano uid is ( ) m = (1 )( ) f + ( ) s .…”

“…@ n i;j =@t = A i;j 2 X n i;j B i;j 2 Y n i;j + C i;j X n i;j + D i;j Y n i;j S i;j ; (35) Step 3. Solve the temperature based on the FHOC scheme for Eq.…”

Entropy Generation and Mixed Convection Flow Inside a Wavy-Walled Enclosure Containing a Rotating Solid Cylinder and a Heat Source

“…Heat and mass transfers generate irreversibility (entropy generation), thus leading to a loss in the efficiency of a real process. Many research works related to entropy generation in cavities can be found in open literature (see Mahmud and Island [ 21 ], Magherbi et al [ 22 ], Zahmatkesh [ 23 ], Voral et al [ 24 ], Ilis et al [ 25 ], Parvin and Chamkha [ 26 ], Chamkha et al [ 27 ], Sheremet et al [ 28 ], Mansour et al [ 29 ], Chamkha et al [ 30 ] and Mehryan et al [ 31 ]).…”

Effect of Magnetic Field Orientation on Nanofluid Free Convection in a Porous Cavity: A Heat Visualization Study

“…MHD free convection and entropy generation of Cu-water nanofluid in a porous cavity with time periodic heating on the mid portion of the left wall were discussed by Malik and Nayak [18]. Mansour et al [19] studied the effect of viscous dissipation on entropy generation due to MHD free convection of Cu-water nanofluid in a porous cavity with active parts. Sheikholeslami and Rokni [20] considered the problem of MHD free convection of CuOwater nanofluid in a porous complex-shaped cavity.…”