Purpose
This study aims to analyze entropy generation and magnetohydrodynamic (MHD) natural convection of hybrid nanofluid in a square cavity, with a heated elliptical block placed at the center, in presence of a periodic-variable magnetic field.
Design/methodology/approach
In this paper, simulations were performed with a FORTRAN home code. The numerical methodology used to solve Navier–Stokes, energy and entropy generation equations with corresponding boundary conditions, is essentially based on the finite volume method and full multigrid acceleration.
Findings
The cavity is filled with Ag–Tio2/Water hybrid nanofluid. The main objective of this investigation is to predict the effects of body’s size (6 cases), type of applied magnetic field (variable or uniform), the non-dimensional period number of the variable magnetic field (VMF) (0.2 ≤ Λ ≤ 0.8), the inclination angle of the VMF (0 ≤ χ ≤ 90), Rayleigh number (5 × 103 ≤ Ra ≥ 105) and Hartmann number (5 ≤ Ha ≥ 100) on thermal performance, heat transfer rate, entropy generation and flow patterns.
Originality/value
To the authors’ best knowledge, this paper is the first numerical investigation deals with the entropy generation and natural convection of hybrid nanofluid in a two-dimensional cavity, with specific thermal boundary conditions, containing an elliptical block under periodic-variable magnetic field. Different combinations between flow-governing parameters were made to find optimal thermal performance.
In this paper, heat transfer and entropy generation of MHD natural convection of Carbone NanoTube (CNT)-water nanofluids in a square cavity with and without isothermal block are numerically studied. The cavity is heated sinusoidally, according to the X coordinate, from below and it is cooled isothermally from the top. The two vertical walls are kept adiabatic. Three cases were investigated: square cavity without block (WB), with cold block (CB), and with hot block (HB). The nonlinear governing equations and boundary conditions are discretized using finite volume approach with the Quick scheme and solved numerically by projection algorithm for the pressure-velocity coupling together with the multigrid solver. Simulations were carried out based on various flow-governing parameters such as Hartmann number (0
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.