Free Convection Heat Transfer and Entropy Generation in an Odd-Shaped Cavity Filled with a Cu-Al2O3 Hybrid Nanofluid

The present paper aims to analyze the thermal convective heat transport and generated irreversibility of water-Cu-Al2O3 hybrid nanosuspension in an odd-shaped cavity. The side walls are adiabatic, and the internal and external borders of the enclosure are isothermally kept at high and low temperatures of Thand Tc, respectively. The control equations based on conservation laws are formulated in dimensionless form and worked out employing the Galerkin finite element technique. The outcomes are demonstrated using streamlines, isothermal lines, heatlines, isolines of Bejan number, as well as the rate of generated entropy and the Nusselt number. Impacts of the Rayleigh number, the hybrid nanoparticles concentration (ϕhnf), the volume fraction of the Cu nanoparticles to ϕhnf ratio (ϕr), width ratio (WR) have been surveyed and discussed. The results show that, for all magnitudes of Rayleigh numbers, increasing nanoparticles concentration intensifies the rate of entropy generation. Moreover, for high Rayleigh numbers, increasing WR enhances the rate of heat transport.

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

MATEC Web of Conferences ◽

10.1051/matecconf/202030701007 ◽

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.

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Entropy generation optimization of unsteady radiative hybrid nanofluid flow over a slippery spinning disk

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211065384 ◽

2022 ◽

pp. 095440622110653

Author(s):

Nilankush Acharya ◽

Suprakash Maity ◽

Prabir K Kundu

Keyword(s):

Heat Transport ◽

Entropy Generation ◽

Volume Fraction ◽

Velocity Slip ◽

Hybrid Nanofluid ◽

Bejan Number ◽

Nanoparticle Concentration ◽

Significant Similarity ◽

Similarity Transformations ◽

Spinning Disk

Entropy generation investigation of hybrid nanofluidic transport over an unsteady spinning disk is reported in this analysis. The magnetic influence, velocity slips, and thermal radiative effects are included within the flow. Ferrous oxide (Fe3O4) and graphene oxide (GO) are used as tiny nano ingredients, and water (H2O) is the base medium. The dimensional leading equations are settled to dimensionless nonlinear ordinary differential equations (ODEs) by significant similarity transformations. Then, classical RK-4 scheme with a shooting process has been initiated to execute the numerical simulation. The software MAPLE-18 is used to run the entire simulation with an indispensable accuracy rate. Several streamlines, graphs, and requisite tables are executed to divulge the parametric impact on the nanofluidic stream. Entropy generation–related figures are depicted for diverse parameters, and parametric effects on Bejan number are also analyzed. Moreover, the corresponding physical consignments like the measure of the frictional hindrance, heat transport are calculated and reviewed. The entropy generation augments for higher magnetic value but reduces for velocity slip, radiation, and nanoparticle concentration. Hybrid nanofluid gives a lower magnitude in entropy production as compared to the usual nanofluid. Magnetic parameter reduces the Bejan number, while slip factor and nanoparticle concentration amplify such effects. Heat transfer ultimately seems to increase for nanoparticle volume fraction, and the increase rate is 4.01685 for usual nanofluid, but it is 6.7557 for hybrid nanofluid. Also, the numerical fallouts address the possibility of using magnetized spinning disks in space engines and nuclear propulsion, and such a model conveys significant applications in heat transport improvement in so many industrial thermal management equipment and renewable energy systems.

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Entropy Generation and Natural Convection Flow of Hybrid Nanofluids in a Partially Divided Wavy Cavity Including Solid Blocks

Energies ◽

10.3390/en13112942 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2942 ◽

Cited By ~ 9

Author(s):

Ammar I. Alsabery ◽

Ishak Hashim ◽

Ahmad Hajjar ◽

Mohammad Ghalambaz ◽

Sohail Nadeem ◽

...

Keyword(s):

Entropy Generation ◽

Convection Flow ◽

Hybrid Nanofluid ◽

Bejan Number ◽

The Finite Element Method ◽

Governing Equations ◽

Flow And Heat Transfer ◽

Hybrid Nanofluids ◽

Wavy Cavity ◽

Rayleigh Numbers

The present investigation addressed the entropy generation, fluid flow, and heat transfer regarding Cu-Al 2 O 3 -water hybrid nanofluids into a complex shape enclosure containing a hot-half partition were addressed. The sidewalls of the enclosure are made of wavy walls including cold isothermal temperature while the upper and lower surfaces remain insulated. The governing equations toward conservation of mass, momentum, and energy were introduced into the form of partial differential equations. The second law of thermodynamic was written for the friction and thermal entropy productions as a function of velocity and temperatures. The governing equations occurred molded into a non-dimensional pattern and explained through the finite element method. Outcomes were investigated for Cu-water, Al 2 O 3 -water, and Cu-Al 2 O 3 -water nanofluids to address the effect of using composite nanoparticles toward the flow and temperature patterns and entropy generation. Findings show that using hybrid nanofluid improves the Nusselt number compared to simple nanofluids. In the case of low Rayleigh numbers, such enhancement is more evident. Changing the geometrical aspects of the cavity induces different effects toward the entropy generation and Bejan number. Generally, the global entropy generation for Cu-Al 2 O 3 -water hybrid nanofluid takes places between the entropy generation values regarding Cu-water and Al 2 O 3 -water nanofluids.

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Conjugate Free Convection Heat Transfer and Thermodynamic Analysis of Infrared Suppression Device with Cylindrical Funnels

Journal of Heat Transfer ◽

10.1115/1.4053455 ◽

2022 ◽

Author(s):

Vikrant Chandrakar ◽

Arnab Mukherjee ◽

Jnana Ranjan Senapati ◽

Ashok Kumar Barik

Keyword(s):

Heat Transfer ◽

Entropy Generation ◽

Convection Heat Transfer ◽

Navier Stokes ◽

Bejan Number ◽

Navier Stokes Equation ◽

Ansys Fluent ◽

Geometric Ratio ◽

Flow Rate Increase ◽

Free Convection Heat

Abstract A convection system can be designed as an energy-efficient one by making a considerable reduction in exergy losses. In this context, entropy generation analysis is performed on the infrared suppression system numerically. In addition, results due to heat transfer are also shown. The numerical solution of the Navier-stokes equation, energy equation, and turbulence equation is executed using ANSYS Fluent 15.0. To perform the numerical analysis, different parameters such as the number of funnels, Rayleigh number (Ra), inner surface temperature, and geometric ratio are varied in the practical range. Results are shown in terms of heat transfer, entropy generation, irreversibility (due to heat transfer and fluid friction), and Bejan number with some relevant parameters. Streamlines and temperature contours are also provided for better visualization of temperature and flow field around the device. Results show that heat transfer and mass flow rate increase with the increase in Ra. Entropy generation and the irreversibility rise with an increase in the number of funnels and geometric ratio. Also, the Bejan number decreases with an increase in Ra and the number of funnels. A cooling time is also obtained using the lumped capacitance method.

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Numerical Analysis of Nanofluids in Differentially Heated Enclosure Undergoing Orthogonal Rotation

Advances in Mathematical Physics ◽

10.1155/2014/874132 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

H. Saleh ◽

I. Hashim

Keyword(s):

Heat Transfer ◽

Transfer Rate ◽

Volume Fraction ◽

Solid Volume Fraction ◽

Convection Heat Transfer ◽

Staggered Grid ◽

Governing Equations ◽

Nanoparticles Concentration ◽

Quantity Of Heat ◽

Velocity Pressure

Natural convection heat transfer in a rotating, differentially heated enclosure is studied numerically in this paper. The rotating enclosure is filled with water-Ag, water-Cu, water-Al2O3, or water-TiO2nanofluids. The governing equations are in velocity, pressure, and temperature formulation and solved using the staggered grid arrangement together with MAC method. The governing parameters considered are the solid volume fraction,0.0 ≤ ϕ ≤ 0.05, and the rotational speeds,3.5≤ Ω ≤ 17.5 rpm, and the centrifugal force is smaller than the Coriolis force and both forces were kept below the buoyancy force. It is found that the angular locations of the local maximums heat transfer were sensitive to rotational speeds and nanoparticles concentration. The global quantity of heat transfer rate increases about 1.5%, 1.1%, 0.8%, and 0.6% by increasing 1%ϕof the nanoparticles Ag, Cu, Al2O3, and TiO2, respectively, for the considered rotational speeds.

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

E3S Web of Conferences ◽

10.1051/e3sconf/202132102004 ◽

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.

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Thermodynamic optimization of nanoﬂuid ﬂow over a non-isothermal wedge with nonlinear radiation and activation energy

Physica Scripta ◽

10.1088/1402-4896/ac45aa ◽

2021 ◽

Author(s):

M R Acharya ◽

P Mishra ◽

Satyananda Panda

Keyword(s):

Heat Transfer ◽

Activation Energy ◽

Reynolds Number ◽

Entropy Generation ◽

Volume Fraction ◽

Mathematical Formulation ◽

Bejan Number ◽

Nanofluid Flow ◽

Entropy Generation Number ◽

Generation Number

Abstract This paper analyses the augmentation entropy generation number for a viscous nanofluid flow over a non-isothermal wedge including the effects of non-linear radiation and activation energy. We discuss the influence of thermodynamically important parameters during the study, namely, the Bejan number, entropy generation number, and the augmentation entropy generation number. The mathematical formulation for thermal conductivity and viscosity of nanofluid for Al2O3 − EG mixture has been considered. The results were numerically computed using implicit Keller-Box method and depicted graphically. The important result is the change in augmentation entropy generation number with Reynolds number. We observed that adding nanoparticles (volume fraction) tend to enhance augmentation entropy generation number for Al2O3 − EG nanofluid. Further, the investigation on the thermodynamic performance of non-isothermal nanofluid flow over a wedge reveals that adding nanoparticles to the base fluid is effective only when the contribution of heat transfer irreversibility is more than fluid friction irreversibility. This work also discusses the physical interpretation of heat transfer irreversibility and pressure drop irreversibility. This dependency includes Reynolds number and volume fraction parameter. Other than these, the research looked at a variety of physical characteristics associated with the flow of fluid, heat and mass transfer.

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Optimal Design of Nanoparticle Enhanced Phan-Thien–Tanner Flow of a Viscoelastic Fluid in a Microchannel

Entropy ◽

10.3390/e20120895 ◽

2018 ◽

Vol 20 (12) ◽

pp. 895

Author(s):

Mohammad Abdollahzadeh Jamalabadi

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Entropy Generation ◽

Volume Fraction ◽

Circular Cross Section ◽

Major Influence ◽

Parameter Study ◽

Bejan Number ◽

Total Entropy ◽

Minimum Entropy

The excellent thermal characteristics of nanoparticles have increased their application in the field of heat transfer. In this paper, a thermophysical and geometrical parameter study is performed to minimize the total entropy generation of the viscoelastic flow of nanofluid. Entropy generation with respect to volume fraction (<0.04), the Reynolds number (20,000–100,000), and the diameter of the microchannel (20–20,000 μm) with the circular cross-section under constant flux are calculated. As is shown, most of the entropy generation owes to heat transfer and by increasing the diameter of the channel, the Bejan number increases. The contribution of heat entropy generation in the microchannel is very poor and the major influence of entropy generation is attributable to friction. The maximum quantity of in-channel entropy generation happens in nanofluids with TiO2, CuO, Cu, and Ag nanoparticles, in turn, despite the fact in the microchannel this behavior is inverted, the minimum entropy generation occurs in nanofluids with CuO, Cu, Ag, and TiO2 nanoparticles, in turn. In the channel and microchannel for all nanofluids except water-TiO2, increasing the volume fraction of nanoparticles decreases entropy generation. In the channel and microchannel the total entropy generation increases by augmentation the Reynolds number.

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Entropy Analysis in Double-Diffusive Convection in Nanofluids through Electro-osmotically Induced Peristaltic Microchannel

Entropy ◽

10.3390/e21100986 ◽

2019 ◽

Vol 21 (10) ◽

pp. 986 ◽

Cited By ~ 3

Author(s):

Noreen ◽

Waheed ◽

Hussanan ◽

Keyword(s):

Brownian Motion ◽

Entropy Generation ◽

Volume Fraction ◽

Motion Parameter ◽

Bejan Number ◽

Double Diffusive Convection ◽

Grashof Number ◽

Diffusive Convection ◽

Double Diffusive ◽

Brownian Motion Parameter

A theoretical study is presented to examine entropy generation in double-diffusive convection in an Electro-osmotic flow (EOF) of nanofluids via a peristaltic microchannel. Buoyancy effects due to change in temperature, solute concentration and nanoparticle volume fraction are also considered. This study was performed under lubrication and Debye-Hückel linearization approximation. The governing equations are solved exactly. The effect of dominant hydrodynamic parameters (thermophoresis, Brownian motion, Soret and Dufour), Grashof numbers (thermal, concentration and nanoparticle) and electro-osmotic parameters on double-diffusive convective flow are discussed. Moreover, trapping, pumping, entropy generation number, Bejan number and heat transfer rate were also examined under the influence of pertinent parameters such as the thermophoresis parameter, the Brownian motion parameter, the Soret parameter, the Dufour parameter, the thermal Grashof number, the solutal Grashof number, the nanoparticle Grashof number, the electro-osmotic parameter and Helmholtz–Smoluchowski velocity. The electro-osmotic parameter powerfully affected the velocity profile. The magnitude of total entropy generation increased as the thermophoresis parameter and Brownian motion parameter increased. Soret and the Dufour parameter had a strong tendency to control the temperature profile and Bejan number. The findings of the present analysis can be used in clinical purposes such as cell therapy, drug delivery systems, pharmaco-dynamic pumps and particles filtration.

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Casson Model of MHD Flow of SA-Based Hybrid Nanofluid Using Caputo Time-Fractional Models

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.390.83 ◽

2019 ◽

Vol 390 ◽

pp. 83-90 ◽

Cited By ~ 2

Author(s):

Sidra Aman ◽

Syazwani Mohd Zokri ◽

Zulkhibri Ismail ◽

Mohd Zuki Salleh ◽

Ilyas Khan

Keyword(s):

Fractional Derivatives ◽

Volume Fraction ◽

Vertical Channel ◽

Mhd Flow ◽

Hybrid Nanoparticles ◽

Hybrid Nanofluid ◽

Caputo Fractional Derivatives ◽

Fractional Models ◽

Hybrid Nanofluids ◽

Time Fractional Derivative

In this paper MHD flow of Casson hybrid nanofluids are investigated with Caputo time-fractional derivative. Alumina (Al) and copper (Cu) are used as nanoparticles in this study with heat, mass transfer and MHD flow over a vertical channel in a porous medium. The problem is modeled using Caputo fractional derivatives and thermophysical properties of hybrid nanoparticles. The influence of concerned parameters is investigated physically and graphically on the heat, concentration and flow. The effect of volume fraction on thermal conductivity of hybrid nanofluids is observed.

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