Journal of Nanofluids最新文献

{"title":"Effect of Variable Viscosity on Entropy Generation Analysis Due to Graphene Oxide Nanofluid Convective Flow in Concentric Cylinders","authors":"Jagadeeshwar Pashikanti, D. R. Susmitha Priyadharshini, A. Chamkha","doi":"10.1166/jon.2024.2114","DOIUrl":"https://doi.org/10.1166/jon.2024.2114","url":null,"abstract":"Aggregated studies of graphene nanoparticles is important for the effective utilization of their striking thermophysical properties and extensive industrial applications. This investigation is one such computational study to explore the flow of graphene oxide nanofluids with temperature\u0000 dependant viscosity between two concentric cylinders. Buongiorno model is used to develop the flow of graphene nanofluids including the impacts of Soret and Dufour effects and the effects of nanoparticle characteristics such as thermophoresis and Brownian motion. The modelled equations are\u0000 transformed and are numerically solved using linearization method together with Chebyshev’s spectral collocation method under convective conditions. The impacts of embedded parameters on temperature, concentration and skin friction profiles of the chosen nanofluid and their consequent\u0000 impacts on the predominant cause for the generated entropy are studied. From the tabulated values of Nusselt number and Sherwood number, it is observed that convective heat transfer can be enhanced by thermal Biot number whereas Soret number enhances diffusive mass transfer and variable viscosity\u0000 parameter preferably reduces the skin friction. A comparison table is presented and it shows that the values obtained from the present method are in good agreement with existing literature. Also, the obtained results are depicted and interpreted in detail. Furthermore, entropy generation is\u0000 analysed and its irreversibilty is calculated.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140773016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Thermal Instability in Magneto-Convection Nanoliquid Confined within Hele-Shaw Cell Under Three Types of Thermal/Gravity Modulation","authors":"S. Rai, B. S. Bhadauria, Anish Kumar, Awanish Kumar","doi":"10.1166/jon.2024.2112","DOIUrl":"https://doi.org/10.1166/jon.2024.2112","url":null,"abstract":"In the present paper, we investigate a thermal instability of magneto-convection in an electrically conducting nanoliquid confined within Hele-Shaw cell, subjected to an applied time-periodic boundary thermal (ATBT) or gravitational modulation (ATGM), and surrounded by a constant vertical\u0000 magnetic field. A steady portion and a time-dependent oscillatory portion constitute the temperature gradient seen between liquid layer’s walls in the context of ATBT. In this scenario, both walls’ temperatures are modulated. The liquid layer oscillation can be used to realise\u0000 the externally applied time periodic component of the gravity field that is present in the ATGM problem. The perturbation is described in terms of the power series of the assumed-small convective amplitude. The impact of modulations on heat/mass transfer are examined utilising Ginzburg-Landau\u0000 (GBL) approach. The impact of different parameters on the transportation of mass and heat is also explored. Additionally, we observe that gravitational modulation is very much effective than thermal modulation. Lewis-number, modified-diffusivity ratio and concentration Rayleigh-number increase\u0000 heat and mass transport in the system.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140786318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetohydrodynamic Free Convective Flow in a Vertical Microchannel with Heat Sink","authors":"J. Prathap Kumar, J. Umavathi, Shivaleela Patil","doi":"10.1166/jon.2024.2150","DOIUrl":"https://doi.org/10.1166/jon.2024.2150","url":null,"abstract":"Electrically conducting fluid flowing past a micro-channel is investigated in the presence of heat sink. The governing equations of the system are non-dimensionalzed by using suitable dimensionless quantities. Exact solutions are computed for the momentum, energy, volume flow rate,\u0000 skin friction and the rate of heat transfer. The impact of flow controlling factors like the fluid-wall interaction parameter, the rarefaction parameter, Hartmann number, suction/injection, and heat sink are presented pictorially. Results show that the velocity is augmented with rarefaction\u0000 parameter whereas it is decelerated with fluid-wall interaction, Hartmann number, and heat sink for all values of temperature difference ratio. Injection retards the flow whereas suction accelerates the flow. The volumetric flow rate decreases for asymmetric heating and increases for symmetric\u0000 heating. The heat sink parameter increases the rate of heat transfer at the right plate whereas it decreases at the left plate. The results which are analyzed have applications in modelling the combustion heat exchangers and nuclear energy.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140759844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Analytical Study of Fluid Flow Through a Porous Filled Channel with Permeable Wall: Suction/Injection Wall Conditions","authors":"D. Bhargavi, Anil Kumar, P. Anantha Lakshmi Narayana, Nitish Gupta","doi":"10.1166/jon.2024.2151","DOIUrl":"https://doi.org/10.1166/jon.2024.2151","url":null,"abstract":"To depict fluid movement in a channel with a rectangle-shaped cross-section and porous walls, the twodimensional Darcy Brinkman equation of motion with uniform suction and injection is analytically solved using the perturbation method. The analytical expressions for non-dimensional\u0000 axial velocity, normal velocity, skin friction coefficient and pressure drop are obtained using the perturbation method at a low Reynolds number. Graphical analysis has been done for the derived quantities for different Darcy and Reynolds numbers. At higher Reynolds numbers, the emergence\u0000 of the velocity overshoots and the presence of an unfavourable pressure gradient zone are significantly less noticeable. The streamlines follow the same pattern since the flow is steady. When the Darcy number is large, the non-dimensional stream function expression reduces to the stream function\u0000 expression available in the literature. Non-dimensional pressure drop increases up to a specific entry length. The skin friction coefficient decreases as the Reynolds number increases. Acceleration of the fluid in the porous region leads to lesser skin friction; hence, pressure drop rises.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140784755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study of Convection Heat Transfer with Confinement Around a Square Cylinder Submerged in a Water-Based Nanofluid","authors":"Jaspinder Kaur, Atharva Tiwari, J. Ratan, A. Tiwari","doi":"10.1166/jon.2024.2140","DOIUrl":"https://doi.org/10.1166/jon.2024.2140","url":null,"abstract":"The novelty of this work lies in the comprehensive investigation of Forced convection heat transfer a square cylinder inclined at 45° using CuO nanofluid employing a single phase approach. A heated square cylinder with constant wall temperature boundary condition, subjected to a\u0000 flowing nanofluid between two parallel walls, undergoes a laminar, steady and two-dimensional flow within a Reynolds number range of 1 < Re > 40. To obtain solutions for the flow and energy transfer, a Finite Element Method (FEM) is employed to numerically solve the governing\u0000 differential equations and boundary conditions. The objective of this work is to highlight the effects of Reynolds number (Re), confinement ratio (λ), volume concentration (Φ) and diameter of nanoparticles (dnp) on fluid flow and heat transfer\u0000 characteristics of nanofluid. To capture the effect of Φ and dnp in nanofluid, the thermo-physical-properties of CuO nanofluid are determined experimentally. In the results, at Re = 40, a secondary separation zone (recirculation zone) is observed near the\u0000 surface of the channel wall. The drag coefficient value rises as the Φ increases and the vdnp decreases, regardless of other factors such as Re and λ. Conversely, as the confinement ratio and volume fraction of nanoparticles increase, the\u0000 average Nusselt number also rises, while maintaining a constant value of Re and dnp. In contrast, the size of the nanoparticles exhibits an inverse relationship with the average Nusselt number. The study contributes to the understanding of nanofluid behavior and provides\u0000 practical insights for applications, supported by correlations and Artificial Neural Network predictions (Parrales et al.).","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140785746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Dipole and Mixed Convective Effect on Boundary Layer Flow of Ferromagnetic Micropolar Hybrid Nanofluid","authors":"Nidhi, L. Kumar","doi":"10.1166/jon.2024.2123","DOIUrl":"https://doi.org/10.1166/jon.2024.2123","url":null,"abstract":"An area of significant interest in research involves the study of magnetic ferrofluids with nanoparticles suspensions, owing to their wide array of applications. A powerful magnetic dipole, in conjunction with an applied magnetic field, enhances the saturation of magnetic particles.\u0000 Keeping in mind, the endeavor aims to analyze the flow of a ferromagnetic micropolar hybrid nanofluid as it passes a shrinking wall considering the impact of mixed convection and magnetic dipole. Apposite similarity transformations are utilized to transform the partial differential equations\u0000 into the relevant nonlinear ordinary differential equations. The acquired system of differential equations is tackled through the effective shooting method to find a solution. The RKF45 method in MATLAB is employed to numerically solve this system of equations. By providing two distinct initial\u0000 guesses, the analysis reveals the presence of dual solutions. The comparison with earlier published results in the literature shows a high level of agreement. Critical values for the shrinking parameter and suction/injection parameter have been obtained. The study delves into the impact of\u0000 emerging variables on various aspects, including temperature profile, velocity profile, microrotation velocity profile, skin friction coefficient, and the reduced Nusselt number through the presentation of graphs and tables. The significant outcome of the current endeavor is that the solution\u0000 to the flow problem is feasible for a range of both s and χ and beyond which there exists no solution. It also clarifies that the flow requires a considerable amount of suction to be feasible. The current effort also shows that the increasing value of both s and χ\u0000 decreases reduced Nusselt number √1/(Re)Nu and increases skin friction coefficient √ReCf.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140770366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Analysis of Magnetohydrodynamic and Dissipated Hybrid Casson Nanofluid Flow Over an Unsteady Stretchable Rotating Disk with Cattaneo-Christov Heat Flux Model","authors":"Ayele Tulu","doi":"10.1166/jon.2023.2059","DOIUrl":"https://doi.org/10.1166/jon.2023.2059","url":null,"abstract":"The study scrutinized MHD and dissipated (SWCNTs-Fe3O4)/C2H6O2 hybrid Casson nanofluids flow over an unsteady stretchable rotating disk with a Cattaneo-Christov heat flux model. By means of proper similarity conversion, the boundary layer flow governing PDEs was changed into systems of dimensionless coupled nonlinear ordinary differential equations. Subsequently, the consequent nonlinear momentum and energy equations with their boundary conditions were worked out numerically employing the spectral quasilinearization method (SQLM). The convergence, stability, and accuracy of the SQLM were established as a computationally efficient method to solve a coupled system of boundary layer problems. It is specified that 5% of SWCNTs, 20% of Fe3O4, and 75% of C2H6O2 being taken for the preparation of (SWCNTs−Fe3O4)/C2H6O2 hybrid nanofluid with shape factor n1 = n2 = 3, and the values of the parameters used are fixed to M = 5, S = 0.5, β = 5, κ = 0.5, Ec = 2, Λ = 2, Pr = 7.3, α = 0.5, δ = 0. The effects of more perceptible parameters on velocity and thermal flow fields were considered and scrutinized carefully via graphs and tables. The results disclose that the momentum and thermal boundary layer thickness markedly declined with more value of the unsteady parameter. The local heat transfer rate improves nearly by 14% as 0.2 volume of Fe3O4 nanoparticles dispersed in 0.05 volume of SWCNTs and 0.75 volume of C2H6O2 nanofluid, hence, in realistic uses adding more values of nanoparticles in the hybrid nanofluids is useful to progress the heating process. The study is novel since to the best of the author’s knowledge, no paper has been published so far on the unsteady flow of (SWNT-Fe3O4)-Ethylene glycol hybrid Casson nanofluid with the effects of the Cattaneo-Christov heat flux model. As well, the model used for the thermophysical properties of the hybrid nanofluid is a new approach. Generally, hybrid nanofluids of (SWCNTs-Fe3O4)/C2H6O2 show better flow distributions with good stability of thermal properties than their mono counterparts.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139328189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-Convective Hartmann Flow of Couple Stress Hybrid Nanofluid Between Two Dilating Parallel Walls with Heat and Mass Transfer","authors":"A. Raju, O. Ojjela, N. Naresh Kumar, I. Sreenath","doi":"10.1166/jon.2023.2053","DOIUrl":"https://doi.org/10.1166/jon.2023.2053","url":null,"abstract":"The study of bio-convective flow of hybrid nanofluid attracted many researchers because of tremendous applications in the fields of biofuel biotechnology, enzyme-based biosensors and biomedical science. The present work addresses a comparative study of CuO/Al2O3-water and CuO-water nanoparticles on heat and mass transfer characteristics of the squeezing flow of MHD couple stress fluid between two parallel plates by suspending motile micro-organisms. An approximated numerical technique (Shooting method along with Runge-Kutta 4th order scheme) have been employed to analyse the system of coupled nonlinear ordinary differential equations. The above numerical investigations were carried out for various governing parameters such as couple stress parameter, Hartmann number, bioconvection Peclet number, squeezing parameter etc. The effects of these physical parameters are illustrated graphically over velocity components, temperature distribution, diffusion of concentration and density of motile microorganisms. In addition to this the numerical values of skin friction, the local Nusselt number and local Sherwood number are tabulated at the upper plate for CuO-water and CuO–Al2O3-water at the expanding and squeezing cases. The numerical results for temperature profiles are in good consistency with earlier research.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139329897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetohydrodynamic Darcy-Forchheimer Squeezed Flow of Casson Nanofluid Over Horizontal Channel with Activation Energy and Thermal Radiation","authors":"V. V. L. Deepthi, R. Srinivasa Raju","doi":"10.1166/jon.2023.2054","DOIUrl":"https://doi.org/10.1166/jon.2023.2054","url":null,"abstract":"The most well-known research areas in computational fluid dynamics are concerned with the interplay of fluid flow with chemical reaction and activation energy. According to the findings of several studies, its industrial applications include simulating the flow inside a nuclear reactor, for which it has received appreciation from many researchers. This study, driven by the use of flow in industrial challenges, explores the impacts of activation energy and chemical reaction on the magnetohydrodynamic (MHD) Darcy–Forchheimer squeezed Casson fluid flow through a porous material across the horizontal channel. The flow is produced when two horizontal plates are compressed to create more space between them. By using similarity variables, one may successfully convert partial differential equations (PDEs) to ordinary differential equations (ODEs). The shooting technique was used to carry out the numerical analysis, which entailed solving the competent governing equations with dominating parameters for a thin liquid layer. This was done to determine the results of the study. To validate the current solutions, it is vital to evaluate the numerical findings alongside the results of the prior research. The findings indicate that fluid velocity and temperature increases may be expected as the plates are brought closer together. In addition, there was a correlation between a rise in the Hartmann number and a decrease in the fluid’s velocity and concentration because of the existence of strong Lorentz forces. The temperature and the concentration of the liquid will increase due to the Brownian motion. When the Darcy–Forchheimer and activation energy parameters are both increased, the velocity and concentration decrease.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139326340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Revised Work on the Rayleigh-Bénard Instability of Nanofluid in a Porous Medium Layer","authors":"A. Ruo, Wei-Mon Yan, Min-Hsing Chang","doi":"10.1166/jon.2023.2052","DOIUrl":"https://doi.org/10.1166/jon.2023.2052","url":null,"abstract":"To reveal the mechanism of the enhanced heat transfer in nanofluids, Buongiorno (ASME J. Heat Transfer, vol. 128, 2006, pp. 240–250) developed a convective transport model by considering the slip mechanisms of nanoparticles migration. By now, many extended researches are based on his model. Among them, the study on porous medium flow pioneered by Nield & Kuznetsov (Int. J. Heat & Mass Transfer, vol. 52, 2009, pp.5796–5801) has received much attention. Their work employed the Darcy model and Buongiorno’s model to investigate the thermal instability in a horizontal porous medium layer saturated by a nanofluid. Through a sophisticated analysis, they obtained an approximate formula capable of predicting the stability threshold. However, a potential contradiction exists in their analysis owing to an improper assumption about the thermophoretic coefficient, which may lead to an unphysical result. To date, much of current works still adopted this improper assumption in various extended problems. To resolve this contradiction, the present study revises their work by considering the dependence of thermophoretic coefficient on the volume fraction of nanoparticles. A nonlinear basic-state solution of concentration is obtained and then used to implement the linear stability analysis. In comparison with Nield’s formula, the present result shows that the threshold of instability shifts to a lower concentration by more than one order of magnitude. The mechanism causing the shift is discussed and the novelty of the present study is stressed.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139325728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}