scholarly journals Lorentz Forces Effects on the Interactions of Nanoparticles in Emerging Mechanisms with Innovative Approach

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1700 ◽  
Author(s):  
Noor Saeed Khan ◽  
Qayyum Shah ◽  
Arif Sohail ◽  
Poom Kumam ◽  
Phatiphat Thounthong ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Leading Edge ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Hybrid Nanofluid ◽  
Similarity Transformations

This paper focuses on advances in the understanding of both the fundamental and applied aspects of nanomaterials. Nanoparticles (titania and graphene oxide) in water-based fluid lying on a surface incorporating the leading edge accretion (or ablation) are analyzed. Entropy generation rate is also considered. The Hall current effect is induced in the flow of hybrid nanofluid, due to which the two-dimensional study converts into three-dimensional space. Similarity transformations convert the equations of momentum, heat transfer, nanoparticles volume fraction and boundary conditions into non-dimensional form. Mathematica software is used to obtain the computation through homotopy analysis method. Analysis is provided through the effects of different parameters on different profiles by sketching the graphs. Flow, heat transfer and nanoparticles concentration in TiO2/H2O, as well as GO-TiO2/H2O, are decreased with increasing the Stefan blowing effect, while entropy generation rate elevates upon increasing each parameter. Both of the velocity components are reduced with increasing the Hall parameter. Streamlines demonstrate that trapping is increased at the left side of the surface. The obtained results are compared with the published work which show the authentication of the present work.

scholarly journals Free convection heat transfer and entropy generation analysis of water-Fe3O4/CNT hybrid nanofluid in a concentric annulus

2019 ◽  
Vol 29 (3) ◽  
pp. 915-934 ◽  
Author(s):  
Amin Shahsavar ◽  
Pouyan Talebizadeh Sardari ◽  
D. Toghraie
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Rayleigh Number ◽  
Entropy Generation ◽  
Average Nusselt Number ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Hybrid Nanofluid ◽  
Content Type ◽  
Thermal Entropy

Purpose This paper aims to numerically investigate the heat transfer and entropy generation characteristics of water-based hybrid nanofluid in natural convection flow inside a concentric horizontal annulus. Design/methodology/approach The hybrid nanofluid is prepared by suspending tetramethylammonium hydroxide-coated Fe3O4 (magnetite) nanoparticles and gum arabic (GA)-coated carbon nanotubes (CNTs) in water. The effects of nanoparticle volume concentration and Rayleigh number on the streamlines, isotherms, average Nusselt number and the thermal, frictional and total entropy generation rates are investigated comprehensively. Findings Results show the advantageous effect of hybrid nanofluid on the average Nusselt number. Furthermore, the study of entropy generation shows the increment of both frictional and thermal entropy generation rates by increasing Fe3O4 and CNT concentrations at various Rayleigh numbers. Increasing Rayleigh number from 103 to 105, at Fe3O4 concentration of 0.9 per cent and CNT concentration of 1.35 per cent, increases the average Nusselt number, thermal entropy generation rate and frictional entropy generation rate by 224.95, 224.65 and 155.25 per cent, respectively. Moreover, increasing the Fe3O4 concentration from 0.5 to 0.9 per cent, at Rayleigh number of 105 and CNT concentration of 1.35 per cent, intensifies the average Nusselt number, thermal entropy generation rate and frictional entropy generation rate by 18.36, 22.78 and 72.7 per cent, respectively. Originality/value To the best knowledge of the authors, there are not any archival publications considering the detailed behaviour of the natural convective heat transfer and entropy generation of hybrid nanofluid in a concentric annulus.

MHD and nonlinear thermal radiation effects on hybrid nanofluid past a wedge with heat source and entropy generation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fazle Mabood ◽  
Anum Shafiq ◽  
Waqar Ahmed Khan ◽  
Irfan Anjum Badruddin
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Heat Source ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Entropy Generation Rate ◽  
Design Parameters ◽  
Hybrid Nanofluid ◽  
Nonlinear Thermal Radiation ◽  
Content Type

Purpose This study aims to investigate the irreversibility associated with the Fe3O4–Co/kerosene hybrid-nanofluid past a wedge with nonlinear radiation and heat source. Design/methodology/approach This study reports the numerical analysis of the hybrid nanofluid model under the implications of the heat source and magnetic field over a static and moving wedge with slips. The second law of thermodynamics is applied with nonlinear thermal radiation. The system that comprises differential equations of partial derivatives is remodeled into the system of differential equations via similarity transformations and then solved through the Runge–Kutta–Fehlberg with shooting technique. The physical parameters, which emerges from the derived system, are discussed in graphical formats. Excellent proficiency in the numerical process is analyzed by comparing the results with available literature in limiting scenarios. Findings The significant outcomes of the current investigation are that the velocity field uplifts for higher velocity slip and magnetic strength. Further, the heat transfer rate is reduced with the incremental values of the Eckert number, while it uplifts with thermal slip and radiation parameters. An increase in Brinkmann’s number uplifts the entropy generation rate, while that peters out the Bejan number. The results of this study are of importance involving in the assessment of the effect of some important design parameters on heat transfer and, consequently, on the optimization of industrial processes. Originality/value This study is original work that reports the hybrid nanofluid model of Fe3O4–Co/kerosene.

Fluid flow and heat transfer of a stratified system during natural convection – influence of chamfered corners

2019 ◽  
Vol 29 (2) ◽  
pp. 470-486 ◽  
Author(s):  
Alireza Rahimi ◽  
Aravindhan Surendar ◽  
Aygul Z. Ibatova ◽  
Abbas Kasaeipoor ◽  
Emad Hasani Malekshah
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Three Dimensional ◽  
Immiscible Fluids ◽  
Content Type ◽  
Flow And Heat Transfer

Purpose This paper aims to investigate the three-dimensional natural convection and entropy generation in the rectangular cuboid cavities included by chamfered triangular partition made by polypropylene. Design/methodology/approach The enclosure is filled by multi-walled carbon nanotubes (MWCNTs)-H2O nanofluid and air as two immiscible fluids. The finite volume approach is used for computation. The fluid flow and heat transfer are considered with combination of local entropy generation due to fluid friction and heat transfer. Moreover, a numerical method is developed based on three-dimensional solution of Navier–Stokes equations. Findings Effects of side ratio of triangular partitions (SR = 0.5, 1 and 2), Rayleigh number (103 < Ra < 105) and solid volume fraction (f = 0.002, 0.004 and 0.01 Vol.%) of nanofluid are investigated on both natural convection characteristic and volumetric entropy generation. The results show that the partitions can be a suitable method to control fluid flow and energy consumption, and three-dimensional solutions renders more accurate results. Originality/value The originality of this work is to study the three-dimensional natural convection and entropy generation of a stratified system.

scholarly journals Heat Transfer Enhancement by Coupling of Carbon Nanotubes and SiO2 Nanofluids: A Numerical Approach

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 937 ◽  
Author(s):  
Fitnat Saba ◽  
Saima Noor ◽  
Naveed Ahmed ◽  
Umar Khan ◽  
Syed Tauseef Mohyud-Din ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Skin Friction Coefficient ◽  
Squeezing Flow ◽  
Hybrid Nanofluid ◽  
Governing Equations ◽  
Similarity Transformations ◽  
Rotating Channel

This article comprises the study of three-dimensional squeezing flow of (CNT-SiO2/H2O) hybrid nanofluid. The flow is confined inside a rotating channel whose lower wall is stretchable as well as permeable. Heat transfer with viscous dissipation is a main subject of interest. We have analyzed mathematically the benefits of hybridizing SiO 2 -based nanofluid with carbon nanotubes ( CNTs ) nanoparticles. To describe the effective thermal conductivity of the CNTs -based nanofluid, a renovated Hamilton–Crosser model (RHCM) has been employed. This model is an extension of Hamilton and Crosser’s model because it also incorporates the effect of the interfacial layer. For the present flow scenario, the governing equations (after the implementation of similarity transformations) results in a set of ordinary differential equations (ODEs). We have solved that system of ODEs, coupled with suitable boundary conditions (BCs), by implementing a newly proposed modified Hermite wavelet method (MHWM). The credibility of the proposed algorithm has been ensured by comparing the procured results with the result obtained by the Runge-Kutta-Fehlberg solution. Moreover, graphical assistance has also been provided to inspect the significance of various embedded parameters on the temperature and velocity profile. The expression for the local Nusselt number and the skin friction coefficient were also derived, and their influential behavior has been briefly discussed.

Numerical Investigation of Local Entropy Generation for Laminar Flow in Rotating-Disk Systems

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Mohammad Shanbghazani ◽  
Vahid Heidarpoor ◽  
Marc A. Rosen ◽  
Iraj Mirzaee
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Laminar Flow ◽  
Entropy Generation ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Local Entropy ◽  
Fluid Friction ◽  
Local Entropy Generation

The entropy generation is investigated numerically in axisymmetric, steady-state, and incompressible laminar flow in a rotating single free disk. The finite-volume method is used for solving the momentum and energy equations needed for the determination of the entropy generation due to heat transfer and fluid friction. The numerical model is validated by comparing it to previously reported analytical and experimental data for momentum and energy. Results are presented in terms of velocity distribution, temperature, local entropy generation rate, Bejan number, and irreversibility ratio distribution for various rotational Reynolds number and physical cases, using dimensionless parameters. It is demonstrated that increasing rotational Reynolds number increases the local entropy generation rate and irreversibility rate, and that the irreversibility is mainly due to heat transfer while the irreversibility associated with fluid friction is minor.

Entropy Generation Minimization in a Pressure-Driven Microflow of Viscoelastic Fluid With Slippage at the Wall: Effect of Conjugate Heat Transfer

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Rajkumar Sarma ◽  
Pranab Kumar Mondal
Keyword(s):  
Heat Transfer ◽  
Viscoelastic Fluid ◽  
Entropy Generation ◽  
Conjugate Heat Transfer ◽  
Applied Pressure ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Minimum Entropy ◽  
Viscoelastic Parameter ◽  
Entropy Generation Minimization

We focus on the entropy generation minimization for the flow of a viscoelastic fluid through a parallel plate microchannel under the combined influences of applied pressure gradient, interfacial slip, and conjugate heat transfer. We use the simplified Phan–Thien–Tanner model (s-PTT) to represent the rheological behavior of the viscoelastic fluid. Using thermal boundary conditions of the third kind, we solve the transport equations analytically to obtain the velocity and temperature distributions in the flow field, which are further used to calculate the entropy generation rate in the analysis. In this study, the influential role of the following dimensionless parameters on entropy generation rate is examined: the viscoelastic parameter (εDe2), slip coefficient (k¯), channel wall thickness (δ), thermal conductivity of the wall (γ), Biot number (Bi) and Peclet number (Pe). We show that there exists a particular value of the abovementioned parameters that lead to a minimum entropy generation rate in the system. We believe the results of this analysis could be of helpful in the optimum design of microfluidic system/devices typically used in thermal management, such as micro-electronic devices, microreactors, and microheat exchangers.

scholarly journals Unsteady Transport Phenomena of Hybrid Al2O3-Cu/H2O Nanofluid Past a Shrinking Slender Cylinder

2021 ◽  
Vol 50 (12) ◽  
pp. 3753-3764
Author(s):  
Nurul Amira Zainal ◽  
Roslinda Nazar ◽  
Kohilavani Naganthran ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Hybrid Nanofluid ◽  
Similarity Transformations ◽  
Flow And Heat Transfer ◽  
Theoretical Investigations ◽  
Suitable Form ◽  
Layer Flow

Theoretical investigations of unsteady boundary layer flow gain interest due to its relatability to practical settings. Thus, this study proposes a unique mathematical model of the unsteady flow and heat transfer in hybrid nanofluid past a permeable shrinking slender cylinder. The suitable form of similarity transformations is adapted to simplify the complex partial differential equations into a solvable form of ordinary differential equations. A built-in bvp4c function in MATLAB software is exercised to elucidate the numerical analysis for certain concerning parameters, including the unsteadiness and curvature parameters. The bvp4c procedure is excellent in providing more than one solution once sufficient predictions are visible. The present analysis further observed dual solutions that exist in the system of equations. Notable findings showed that by increasing the nanoparticles volume fraction, the skin friction coefficient increases in accordance with the heat transfer rate. In contrast, the decline of the unsteadiness parameter demonstrates a downward trend toward the heat transfer performance.

Modeling heat transfer of nanofluid flow in microchannels with electrokinetic and slippery effects using Buongiorno’s model

2019 ◽  
Vol 29 (8) ◽  
pp. 2566-2587 ◽  
Author(s):  
Hang Xu ◽  
Huang Huang ◽  
Xiao-Hang Xu ◽  
Qiang Sun
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Slip Length ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Lower Wall ◽  
Volumetric Concentration ◽  
Nanofluid Flow ◽  
Cross Sectional ◽  
Content Type

PurposeThis paper aims to study the heat transfer of nanofluid flow driven by the move of channel walls in a microchannel under the effects of the electrical double layer and slippery properties of channel walls. The distributions of velocity, temperature and nanoparticle volumetric concentration are analyzed under different slip-length. Also, the variation rates of flow velocity, temperature, concentration of nanoparticle, the pressure constant, the local volumetric entropy generation rate and the total cross-sectional entropy generation are analyzed.Design/methodology/approachA recently developed model is chosen which is robust and reasonable from the point of view of physics, as it does not impose nonphysical boundary conditions, for instance, the zero electrical potential in the middle plane of the channel or the artificial pressure constant. The governing equations of flow motion, energy, electrical double layer and stream potential are derived with slip boundary condition presented. The model is non-dimensionalized and solved by using the homotopy analysis method.FindingsSlip-length has significant influences on the velocity, temperature and nanoparticle volumetric concentration of the nanofluid. It also has strong effects on the pressure constant. With the increase of the slip-length, the pressure constant of the nanofluid in the horizontal microchannel decreases. Both the local volumetric entropy generation rate and total cross-sectional entropy generation rate are significantly affected by both the slip-length of the lower wall and the thermal diffusion. The local volumetric entropy generation rate at the upper wall is always higher than that around the lower wall. Also, the larger the slip-length is, the lower the total cross-sectional entropy generation rate is when the thermal diffusion is moderate.Originality/valueThe findings in this work on the heat transfer and flow phenomena of the nanofluid in microchannel are expected to make a contribution to guide the design of micro-electro-mechanical systems.

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