MIXED CONVECTION WITH ENTROPY GENERATION IN A SQUARE CAVITY FILLED WITH HYBRID NANOFLUID

2020 ◽  
Vol 19 (1) ◽  
pp. 155-174
Author(s):  
Ilhem Zeghbid ◽  
Rachid Bessaih
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Hybrid Nanofluid ◽  
Square Cavity

scholarly journals Entropy generation of a hybrid nanofluid on MHD mixed convection is a lid-driven cavity with partial heating having two rounded corners

2021 ◽  
Vol 321 ◽  
pp. 02004
Author(s):  
Zakaria Korei ◽  
Smail Benissaad
Keyword(s):  
Thermal Conductivity ◽  
Reynolds Number ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Object Oriented ◽  
Reynolds Numbers ◽  
Hybrid Nanofluid ◽  
Driven Cavity ◽  
Partial Heating

This research aims to investigate thermal and flow behaviors and entropy generation of magnetohydrodynamic Al2O3-Cu/water hybrid nanofluid in a lid-driven cavity having two rounded corners. A solver based on C ++ object-oriented language was developed where the finite volume was used. Parameter’s analysis is provided by varying Reynolds numbers (Re), Hartmann numbers (Ha), the volume fraction of hybrid nanofluid (ϕ), radii of the rounded corners. The findings show that reducing the radii of the rounded corners minimizes the irreversibility. Furthermore, the thermal conductivity and dynamic viscosity of hybrid nanofluid contribute to increasing the irreversibility. Finally, the entropy generation is decreased by increasing the Hartman number and increases by rising the Reynolds number.

Impacts of heated rotating inner cylinder and two-phase nanofluid model on entropy generation and mixed convection in a square cavity

2019 ◽  
Vol 56 (1) ◽  
pp. 321-338 ◽  
Author(s):  
Ammar I. Alsabery ◽  
Engin Gedik ◽  
Ali J. Chamkha ◽  
Ishak Hashim
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Square Cavity ◽  
Two Phase

scholarly journals Prandtl Number Effects on the Entropy Generation During the Transient Mixed Convection in a Square Cavity Heated from Below

2021 ◽  
Author(s):  
Nawal Ferroudj ◽  
Hasan Koten ◽  
Sacia Kachi ◽  
Saadoun Boudebous
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Working Fluid ◽  
Square Cavity ◽  
Nusselt Numbers ◽  
The Impact

This numerical study considers the mixed convection, heat transfer and the entropy generation within a square cavity partially heated from below with moving cooled vertical sidewalls. All the other horizontal sides of the cavity are assumed adiabatic. The governing equations, in stream function–vorticity form, are discretized and solved using the finite difference method. Numerical simulations are carried out, by varying the Richardson number, to show the impact of the Prandtl number on the thermal, flow fields, and more particularly on the entropy generation. Three working fluid, generally used in practice, namely mercury (Pr = 0.0251), air (Pr = 0.7296) and water (Pr = 6.263) are investigated and compared. Predicted streamlines, isotherms, entropy generation, as well as average Nusselt numbers are presented. The obtained results reveal that the impact of the Prandtl number is relatively significant both on the heat transfer performance and on the entropy generation. The average Nusselt number increase with increasing Prandtl number. Its value varies thereabouts from 3.7 to 3.8 for mercury, from 5.5 to 13 for air and, from 12.5 to 15 for water. In addition, it is found that the total average entropy generation is significantly higher in the case of mercury (Pr«1) and water (Pr»1) than in the case of air (Pr~1). Its value varies approximately from 700 to 1100 W/m3 K for mercury, from 200 to 500 W/m3 K for water and, from 0.03 to 5 W/m3 K for air.    

scholarly journals Entropy generation due to the mixed convection flow of MWCNT−MgO/water hybrid nanofluid in a vented complex shape cavity

2020 ◽  
Vol 307 ◽  
pp. 01007
Author(s):  
Mahdi Benzema ◽  
Youb Khaled Benkahla ◽  
Ahlem Boudiaf ◽  
Seif-Eddine Ouyahia ◽  
Mohammed El Ganaoui
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Complex Shape ◽  
Volume Fraction ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Convection Flow ◽  
Hybrid Nanofluid ◽  
Bejan Number ◽  
Inclined Plate

This paper reports a numerical study of mixed convection heat transfer with entropy generation in a vented complex shape cavity filled with MWCNT−MgO (15:85 vol %) /water hybrid nanofluid. A hot source is placed at the mid potion of the inclined plate of the enclosure, while the rest of the rigid walls are adiabatic. A thermo-dependent correlations proposed by [12] for the dynamic viscosity and the thermal conductivity, especially developed for the considered fluid, are used. After validation of the model, the analysis has been done for a Reynolds numbers ranging from 10 to 600 and total nanoparticles volume fraction ranging from 0.0 to 0.02 using the finite volume method. The predicted results of streamlines, isotherms, isentropic lines, average Nusselt number, average entropy generation and average Bejan number are the main focus of interest in the present paper.

Thermal performance analysis of hybrid nanofluid natural convection in a square cavity containing an elliptical obstacle under variable magnetic field

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Soufien Belhaj ◽  
Brahim Ben-Beya
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Boundary Conditions ◽  
Entropy Generation ◽  
Thermal Performance ◽  
Field Variable ◽  
Variable Magnetic Field ◽  
Hybrid Nanofluid ◽  
Square Cavity ◽  
Content Type

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.

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