Two‐phase study of nanofluids mixed convection and entropy generation in an I‐shaped porous cavity with triangular hot block and different aspect ratios

2020 ◽  
Author(s):  
Amin Asadi ◽  
Siamak Rafizadeh ◽  
Maysam Molana ◽  
Ramin Ghasemiasl ◽  
Taher Armaghani
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Two Phase ◽  
Porous Cavity ◽  
Aspect Ratios ◽  
Phase Study

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

Entropy Generation Analysis of Mixed Convection Flow in a Nanofluid Filled Porous Cavity Using a Two-Component Lattice Boltzmann Method

2019 ◽  
Author(s):  
Dhrubajyoti Kashyap ◽  
Anoop K. Dass
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Lattice Boltzmann ◽  
Lattice Boltzmann Model ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Two Phase ◽  
Good Concordance

Abstract In the present work, a comprehensive analysis is made to understand the effect of velocity boundary conditions on the flow and thermal behaviour during mixed convection flow in a nanofluid-saturated porous square cavity. Two different velocity boundary conditions based on the movement of horizontal walls of the cavity are considered. The vertical fixed walls are differentially heated and the horizontal lids are thermally insulated. We have adopted the two-phase thermal lattice Boltzmann model (TLBM) for nanofluid system and modified this model to simulate nanofluid-filled porous medium by incorporating the Brinkman–Forchheimer-extended Darcy model. The current results provide good concordance with the published results computed through conventional numerical techniques. The detailed study of the heat transfer rate, entropy generation is made for discretely varying Richardson numbers (Ri) from 0.1 to 10 and Darcy numbers (Da) from 10−4 to 10−2 while maintaining Grashof number (Gr) at 104 and volume fractions of Cu nanoparticle (ϕ) less than equal to 5%. It is observed from the results that the optimal flow condition in terms of energy efficiency depends on the values of Ri and Da. From the viewpoint of both 1st and 2nd laws of thermodynamics, the performance of nanofluid is not satisfactory compared to the base fluid for current configurations as the augmentation of entropy generation with ϕ is more prominent compared to heat transfer enhancement.

scholarly journals A New Thermal Conductivity Model and Two-Phase Mixed Convection of CuO–Water Nanofluids in a Novel I-Shaped Porous Cavity Heated by Oriented Triangular Hot Block

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2219
Author(s):  
Amin Asadi ◽  
Maysam Molana ◽  
Ramin Ghasemiasl ◽  
Taher Armaghani ◽  
Mihail-Ioan Pop ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Mixed Convection ◽  
Volume Concentration ◽  
Cooling System ◽  
Two Phase ◽  
Maximum Enhancement ◽  
Cooling Performance ◽  
Porous Cavity ◽  
Thermal Conductivity Model ◽  
The Right

This paper investigates the cooling performance of nanofluid (NF) mixed convection in a porous I-shaped electronic chip with an internal triangular hot block using Buongiorno’s two-phase model. This type of cavity and hot block geometry has not been studied formerly. The NF was assumed to be a mixture of water and CuO nanoparticles (NP) up to 4% of volume concentration. As most published mathematical models for the thermal conductivity of NF give inaccurate predictions, a new predictive correlation for effective thermal conductivity was also developed with a high accuracy compared to the experimental data. The results showed that any increase in the NP volume concentration enhances the average Nusselt number (Nu¯) and the normalized entropy generation, and reduces the thermal performance of the cavity in all orientations of the hot block. The maximum enhancement in cooling performance was 17.75% and occurred in the right-oriented hot block in the sand-based porous cavity. Furthermore, adding the NP to the base fluid leads to a more capable cooling system and enhances the irreversibility of the process.

scholarly journals Control of Magnetohydrodynamic Mixed Convection and Entropy Generation in a Porous Cavity by Using Double Rotating Cylinders and Curved Partition

ACS Omega ◽  
2021 ◽  
Author(s):  
Walid Hassen ◽  
Fatih Selimefendigil ◽  
Nidhal Ben Khedher ◽  
Lioua Kolsi ◽  
Mohamed Naceur Borjini ◽  
...  
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Rotating Cylinders ◽  
Porous Cavity

Entropy generation of a nanofluid in a porous cavity with sinusoidal temperature at the walls and a heat source bellow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dalia Sabina Cimpean ◽  
Ioan Pop
Keyword(s):  
Heat Source ◽  
Entropy Generation ◽  
Amplitude Ratio ◽  
Brownian Diffusion ◽  
Two Phase ◽  
Content Type ◽  
Energy Devices ◽  
Porous Cavity ◽  
Phase Deviation ◽  
Sinusoidal Temperature

Purpose This paper aims to focus on the analysis of the entropy generation in an inclined square cavity filled with a porous media saturated by a nanofluid with sinusoidal temperature distribution on the side walls, adiabatic conditions on the upper wall and a heat source at the lower wall. Design/methodology/approach The two-phase nanofluid model including the Brownian diffusion and thermophoresis effects has been used for simulation of nanofluid transport inside the porous cavity. The governing equations and the entropy generation owing to fluid friction, heat and mass transfer are transformed in terms of the dimensionless variables, and the results are obtained by using the finite difference method of the second-order accuracy. Findings The numerical results of the model are investigated, and the effect of different important parameters, such as inclination angle of the cavity, amplitude ratio of the sinusoidal temperature or phase deviation, is discussed. The results for no inclination of the cavity is compared and successfully validated with previous reported results of the literature. The important findings of the study are focused mainly on the existence of the irreversibility phenomena which are affected by the conditions of the model and the values of the studied parameters. Originality/value The originality of this work is given by the presented mathematical model, the numerical solution with new results for entropy generation in an inclined porous cavity filled by a nanofluid and the applications for design of electronic or energy devices.

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