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Showing papers on "Nanofluid published in 2021"


Journal ArticleDOI
TL;DR: In this paper, the authors present empirical and numerical analyses of thermal performance development in flat plate solar collectors (FPSCs) and provide a complete overview of the up-to-date developments, methods, critical economic factors, the significance of solar water heating, and the challenges faced by the implementations of such solar energy heating systems.

262 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of thermal radiation and surface roughness on the complex dynamics of water conveying alumina and copper oxide nanoparticles, in the case where the thermophysical properties of the resulting mixture vary meaningfully with the volume fraction of solid nanomaterials, as well as with the Brownian motion and thermophoresis microscopic phenomena.
Abstract: Sequel to the fact that hybrid nanofluidic systems (e.g. scalable micro-/nanofluidic device) exhibit greater thermal resistance with increasing nanoparticle concentration, little is known on the significance of thermal radiation, surface roughness and linear stability of water conveying alumina and copper oxide nanoparticles. This study presents the effects of thermal radiation and surface roughness on the complex dynamics of water conveying alumina and copper oxide nanoparticles, in the case where the thermophysical properties of the resulting mixture vary meaningfully with the volume fraction of solid nanomaterials, as well as with the Brownian motion and thermophoresis microscopic phenomena. Based on the linear stability theory and normal mode analysis method, the basic partial differential equations governing the transport phenomenon were non-dimensionalized to obtain the simplified stability equations. The optimum values of the critical thermal Rayleigh number depicting the onset of thermo-magneto-hydrodynamic instabilities were obtained using the power series method and the Chock–Schechter numerical integration. The increase in the strength of Lorentz forces, thermal radiation and surface roughness has a stronger stabilizing impact on the appearance of convection cells. On the contrary, the stability diminishes with the increasing values of the volumetric fraction and diameter of nanomaterials. The partial substitution of the alumina nanoparticles by the copper oxide nanomaterials in the mixture stabilizes importantly the hybrid nanofluidic medium.

225 citations


Journal ArticleDOI
TL;DR: In this article, a new method for measuring the convective heat transfer coefficient (CHTC) of aerosol cooling was proposed, and measuring equipment was designed and built, and results showed that the measurement error of the measurement system was 0.044 (10−2 W/mm2 K).

184 citations


Journal ArticleDOI
TL;DR: A review of the progress made in the area of nanofluids preparation and applications in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling is presented in this paper.
Abstract: The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in the later part of the twentieth century This is evident from the increased number of studies related to nanofluids published annually The increasing attention on nanofluids is primarily due to their enhanced thermophysical properties and their ability to be incorporated into a wide range of thermal applications ranging from enhancing the effectiveness of heat exchangers used in industries to solar energy harvesting for renewable energy production Owing to the increasing number of studies relating to nanofluids, there is a need for a holistic review of the progress and steps taken in 2019 concerning their application in heat transfer devices This review takes a retrospective look at the year 2019 by reviewing the progress made in the area of nanofluids preparation and the applications of nanofluids in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling This review aims to update readers on recent progress while also highlighting the challenges and future of nanofluids as the next-generation heat transfer fluids Finally, a conclusion on the merits and demerits of nanofluids is presented along with recommendations for future studies that would mobilise the rapid commercialisation of nanofluids

181 citations


Journal ArticleDOI
TL;DR: A review of literature on the effects of using nanofluids (NFs) in energy systems is presented in this paper, where different types of NFs, including the combination of metal and non-metal particles of nanometer sizes with a base fluid, are introduced.

167 citations


Journal ArticleDOI
TL;DR: In this paper, the importance of different forces in nanofluid flows that exist in particulate flows such as drag, lift (Magnus and Saffman), Brownian, thermophoretic, Van der Waals, electrostatic double layer forces are considered.

165 citations


Journal ArticleDOI
16 Apr 2021
TL;DR: In this paper, the steady Marangoni driven boundary layer flow, heat and mass transfer characteristics of a nanofluid were studied using the Runge-Kutta-Fehlberg fourth-fifth order (RKF-45) method.
Abstract: The flow and heat transfer of non-Newtonian nanofluids has an extensive range of applications in oceanography, the cooling of metallic plates, melt-spinning, the movement of biological fluids, heat exchangers technology, coating and suspensions. In view of these applications, we studied the steady Marangoni driven boundary layer flow, heat and mass transfer characteristics of a nanofluid. A non-Newtonian second-grade liquid model is used to deliberate the effect of activation energy on the chemically reactive non-Newtonian nanofluid. By applying suitable similarity transformations, the system of governing equations is transformed into a set of ordinary differential equations. These reduced equations are tackled numerically using the Runge–Kutta–Fehlberg fourth-fifth order (RKF-45) method. The velocity, concentration, thermal fields and rate of heat transfer are explored for the embedded non-dimensional parameters graphically. Our results revealed that the escalating values of the Marangoni number improve the velocity gradient and reduce the heat transfer. As the values of the porosity parameter increase, the velocity gradient is reduced and the heat transfer is improved. Finally, the Nusselt number is found to decline as the porosity parameter increases.

163 citations



Journal ArticleDOI
TL;DR: In this paper, an adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) were used for predicting the relative viscosity and electrical conductivity of the two types of hybrid ferrofluids.
Abstract: Recently, the suspension of hybrid nanoparticles in conventional fluids has been investigated as a technique for improving the thermophysical properties of nanofluids. The dearth of documentation on the trio influence of volume concentration, base fluid, and temperature on the electrical conductivity and viscosity of hybrid alumina–ferrofluids [Al2O3–Fe2O3 (25:75 mass%)] has led to this study. The effective viscosity and electrical conductivity of the deionized water (DW)-based and ethylene glycol (EG)–DW-based (50:50 vol%) hybrid alumina–ferrofluids were measured at temperatures of 20–50 °C and volume concentrations of 0.05–0.75%. Based on the importance of soft computing methods to engineers, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) were used for predicting the relative viscosity and electrical conductivity of the two types of hybrid ferrofluids. The measured data for viscosity and electrical conductivity were used in the modeling. Model performances were evaluated using the root mean squared error index. Viscosity was enhanced by 3.23–43.64% and 2.79–49.38%, while electrical conductivity was increased by 163.37–1692.16% and 717.14–7618.89% for the DW- and EG–DIW-based hybrid ferrofluids, respectively, compared with the respective base fluids. Increasing volume concentration augmented the viscosity and electrical conductivity of all the hybrid alumina–ferrofluids, whereas a rise in temperature enhanced their electrical conductivity and detracted the viscosity. DW-based hybrid alumina–ferrofluid was observed to have a lower viscosity and higher electrical conductivity than the EG–DW-based counterpart. The results showed that the optimum ANN and ANFIS models have a maximum error of less than 4.5% and 3.9% for relative viscosity and electrical conductivity, respectively, which were lower than those proposed using regression analysis. With the hybrid alumina–ferrofluids possessing a lower viscosity relative to single-particle ferrofluids, they are recommended for engineering application.

154 citations


Journal ArticleDOI
TL;DR: In this article, a mathematical analysis for three-dimensional Eyring-Powell nanofluid nonlinear thermal radiation with modified heat plus mass fluxes is investigated, and the slip condition is introduced to enhance the dynamical and physical study of structure.
Abstract: In this paper, a mathematical analysis for three-dimensional Eyring–Powell nanofluid nonlinear thermal radiation with modified heat plus mass fluxes is investigated. To enhance the dynamical and physical study of structure, the slip condition is introduced. A Riga plate is employed for avoiding boundary-layer separation to diminish the friction and pressure drag of submarines. To evaluate the heat transfer, the Cattaneo–Christov heat flux model is implemented via appropriate transformation. A comparison between bvp4c results and shooting technique is made. Graphical and numerical illustrations are presented for prominent parameters.

151 citations


Journal ArticleDOI
TL;DR: In this article, the thermal properties of AA7072-AA7075/water-based hybrid nanofluid over a curved stretching sheet using non-Fourier heat flux model were analyzed.

Journal ArticleDOI
TL;DR: In this paper, the stagnation point flow of hybrid nanofluid with inclined magnetic field over a moving cylinder is analyzed and the heat transfer rate on the surface of the nonlinear stretching cylinder is investigated.

Journal ArticleDOI
TL;DR: In this article, the effects of different shape factors have been investigated for a mixture of water and nanofluid with hybrid nanoparticles (MWCNT-Ag) over a vertical stretching cylinder, while a magnetic field has been applied to the system.
Abstract: In this study, flow of a mixture of water and ethylene glycol (50–50%) with hybrid nanoparticles (MWCNT–Ag) over a vertical stretching cylinder has been investigated. In this research, the fluid passes through a porous media, while a magnetic field has been applied to the system. Furthermore, the effects of thermal radiation, viscous dissipation, and natural convection have been studied. As a novelty, the effects of different shape factors have been investigated. In the first step, the governing equations are extracted from partial differential equations and then converted to ordinary differential equations (ODE) using the similarity solution. In the next step, the fifth-order Runge–Kutta method has been used to solve the related ODEs. The effects of parameters such as magnetic field, radiation parameter, porosity parameter, nanofluid volume fraction, and nanofluid shape factor on dimensionless velocity and temperature profile have been presented for single and hybrid nanofluid. The results showed that at $$\eta$$ = 2.5 for hybrid nanoparticles the shape factors lamina and spherical have the largest difference; lamina is smaller by 6%, also the results demonstrated that at $$\eta$$ = 2 with increasing Ha, the radial velocity reduced 9.68% for hybrid nanoparticles.

Journal ArticleDOI
TL;DR: In this article, the authors used hybrid nanofluid past an inside solar wings parabolic trough solar collector (PTSC) to rich the studies of the solar aircraft wings.
Abstract: Solar energy is the leading thermal source from the sun, with huge use of technology such as photovoltaic cells, solar power plates, photovoltaic lighting, and solar pumping water. The current effort deals with solar energy analysis and a technique to enhance solar aircraft effectiveness by using solar and nanotechnological energy. The work is based on the investigation of thermal transfer by utilizing hybrid nanofluid past an inside solar wings parabolic trough solar collector (PTSC) to rich the studies of the solar aircraft wings. The thermal source is titled solar radiative flow. For various properties such as porous media, Cattaneo Christov heat flux, viscous dissipation, play heating and thermal energy flow, the heat transfer efficiency of the wings is verified. In the case of the tangent hyperbolic fluid, the entropy generation analysis was applied. The modeled energy and momentum equations were managed using the well-established numerical plan known as the Keller box process. This paper is made up of double-different kinds of nano solid particles, Cu (copper) and ZrO2 (zirconium dioxide) in EG (ethylene glycol) as standard fluid. Various control parameters are discussed and shown in figures and tables for velocity, shear stress, temperature outlines, frictional factor, and Nusselt number. The efficiency in the aircraft wings in the case of thermal radiation amplification and variable thermal conduction parameters is seen to be improved in terms of thermal transfer. In comparison to the traditional nanofluid, hybrid nanofluid is the ideal source of heat transfer. The thermal efficiency of ZrO2–Cu/EG compared to Cu-EG decreases to a low of 2.6% and peaks to 3.6%.

Journal ArticleDOI
TL;DR: In this article, six-lobed absorber tube equipped with combined turbulators was investigated to enhance the productivity of solar unit, hybrid nanoparticles were added in to working fluid.

Journal ArticleDOI
TL;DR: In this paper, the effects of the radiation parameter, porosity, and the magnetic parameter have been analyzed on temperature distribution and fluid flow streamlines and also, on the local and average Nusselt numbers.
Abstract: Investigation of fluid behavior in a cavity enclosure has been a significant issue from the past in the field of fluid mechanics. In the present study, hydrothermal evaluation of hybrid nanofluid with a water–ethylene glycol (50–50%) as the base fluid which contains MoS2–TiO2 hybrid nanoparticles, in an octagon with an elliptical cavity in the middle of it, has been performed. In this problem, the effects of the radiation parameter, porosity, and the magnetic parameter have been analyzed on temperature distribution and fluid flow streamlines and also, on the local and average Nusselt numbers. The governing equations have been solved by the finite element method (FEM). As a novelty, the Taguchi method has been utilized for test design. Further, the response surface method (RSM) has been applied to achieving the optimum value of the involved parameters. The obtained results illustrate that with an augment in the Rayleigh number from 10 to 100, the average Nusselt number will improve by about 61.82%. Additionally, regarding the correlation, it is indeed transparent that the Rayleigh number has the most colossal contribution comparing other factors on the achieved equation, by about 61.88%.

Journal ArticleDOI
TL;DR: In this article, the radiative unsteady magnetohydrodynamic flow of an incompressible viscous electrically conducting non-Newtonian Casson hybrid nanofluid over an infinite exponentially accelerated vertical moving porous surface under the influence of slip velocity in a rotating frame has been explored.

Journal ArticleDOI
TL;DR: In this paper, the authors provide a comprehensive overview of this body of literature from an environmental perspective and highlight areas for future work that could help ensure that nanofluids have a net positive environmental impact in renewable energy systems going forward.

Journal ArticleDOI
TL;DR: In this article, a time-dependent flow of magnetized rheological Carreau nanoliquid conveying microorganisms over a moving wedge with velocity slip and thermal radiation features is considered.
Abstract: This article addresses the time-dependent flow of magnetized rheological Carreau nanoliquid conveying microorganisms over a moving wedge with velocity slip and thermal radiation features. Carreau fluid is auspicious to depict several types of physical issues because this fluid model has the capability of revealing the rheology of multiple specific fluids such as fluids with brief-chain suspension particles, fluid crystals, detergents, and blood in animals and humans. The mathematical formulation is developed by combining the impact of infinite shear rate viscosity. The physical aspects for both static and moving are discussed in detail. At first, relevant similarity transformations are employed to obtain dimensionless form of equations, and then renovated equations have been solved numerically by employing bvp4c via MATLAB based on shooting technique. Both the numerical and graphical results against physical quantities, such as velocity temperature, nanoparticles concentration and density of gyrotactic microorganism, are observed under the influence of physical parameters.

Journal ArticleDOI
TL;DR: In this article, the effect of aluminum oxide suspended in water at concentration of 0.03% as nanomaterial for turbulent flow using multiple twisted tapes (TTn) in a solar flat plate collector was scrutinized.


Journal ArticleDOI
Wasim Jamshed1
TL;DR: In this paper, the entropy generation in a magnetohydrodynamic flow of a Maxwell nanofluid over an infinite horizontal surface was analyzed. And the remarkable finding of this work is that the thermal conductivity in Maxwell phenomena gradually increases as compared to the conventional fluid.

Journal ArticleDOI
TL;DR: In this article, the irreversibility in convective nanofluid flow in the occurrence of a magnetic field (MHD) in a cavity with chamfers is calculated by numerical approach.
Abstract: The irreversibility in convective nanofluid flow in the occurrence of a magnetic field (MHD) in a cavity with chamfers is calculated by numerical approach. The nanofluid flow is considered under the impacts of magnetic field and thermal gradient. The continuity, motion and energy equations are solved by applying COMSOL Multiphysics computer package. The impacts of $$({\text{Ha}})$$ Hartmann number, $$(\gamma )$$ elevation of magnetic field, nanoparticle volume fraction, heat transmission and entropy analysis on the flow of nanofluid are discussed. Results reveal that, the impacts of volume fraction and the magnetic force on different irreversibility are significant. Moreover, results indicate the existence of a critical $$({\text{Ha}}_{{\text{c}}} )$$ Hartmann number this represents the frontier between the domains where the magnetic field dominates via its intrinsic effect and its extrinsic effect.

Journal ArticleDOI
TL;DR: In this article, the authors reviewed the most recently published works on plasmonic nanofluids that exclusively present its preparation methods, thermophysical properties, and applications in solar collectors.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the magnetic force and nonlinear thermal radiation on hybrid bio-nanofluid flow in a peristaltic channel under the influence of an applied magnetic field with high and low Reynolds number.

Journal ArticleDOI
TL;DR: In this paper, the effects of fin's length and different types of heat sinks with various lengths on the entropy generation rate (EGR) and Nusselt number (Nu) were investigated at different Richardson numbers (Ri) considering slip and non-slip conditions.

Journal ArticleDOI
TL;DR: In this paper, the effects of thermal radiation and activation energy are also considered for dispersing the nanoparticles within base fluid is a newly approach for implementations of heat transfer and biomedicine/bioengineering.
Abstract: The nanoparticles proved a motivating research area in the fourth generation of the world due to their extensive use in science and infrastructure, such as vehicle cooling, higher heat transfer rates in microchips, food manufacturing, biotechnology, biochemistry, transportation, metrology and nuclear reactors. Dispersing the nanoparticles within base fluid is a newly approach for implementations of heat transfer and biomedicine/bioengineering. The current determination is committed to explore the features of bioconvection in Carreau nanofluid flow under the influence of various thermal consequences. The flow is originated by a stretched cylinder. The characteristics of Cattaneo-Christov heat and mass flux are applied to examine the heat/mass transportation of nanofluid. The effects of thermal radiation and activation energy are also considered. The consequences of Brownian movement and thermophoresis features are analyzed by incorporating Buongiorno’s nanofluid model. The governing partial differential equations are transmuted into the structure of nonlinear ordinary differential equations by introducing suitable transformation. The shooting technique is used to achieve the numerical simulations of nonlinear system. The physical impacts of prominent parameters on velocity, temperature distribution, concentration field and microorganisms profile are examined and captured graphically. The numerical outcomes against various flow quantities are also presented in tabular form. The results convey that a higher temperature profile is observed with larger values of thermal Biot number, exponential base sink parameter and thermal relaxation parameter while a decrement in temperature is noticed with increasing mixed convection parameter. The concentration profile shows an increasing trend with mass concentration parameter and concentration relaxation parameter. Moreover, the microorganism field decline with Peclet number and bioconvection Lewis number.

Journal ArticleDOI
TL;DR: In this paper, the impact of Cattaneo-Christov model and convective boundary on second-grade nanofluid flow alongside a Riga pattern is investigated.
Abstract: Present communication aims to determine the impact of Cattaneo–Christov model and convective boundary on second-grade nanofluid flow alongside a Riga pattern. Zero mass flux is accounted at the solid surface of Riga pattern such that the fraction of nanoparticles maintains itself on strong retardation. The impact of Lorentz forces generated by Riga pate is also an important aspect of the study. The governing nonlinear problem is converted into ordinary problems via suitably adjusted transformations. Spectral local linearization method has been incorporated to find the solutions of the nonlinear problems. Variation in horizontal movement of the nanofluid, thermal distribution and concentration distribution of the nanoparticles has been noted for various fluid parameters. The results are plotted graphically. Outcomes indicate that the horizontal movement gains enhancement for elevated values of modified Hartman factor. Thermal state of the nanofluid and concentration of nanoparticles receive reduction for incremental values of relaxation time parameters. Numerical results for skin friction and heat flux have been reported in tabular form. The CPU run time and residual error are obtained to check the efficiency of the method used for finding the solution.

Journal ArticleDOI
TL;DR: In this paper, the properties, preparation and stability of hybrid nanofluids (HNFs) are investigated, and some models and correlations for predicting HNFs properties are presented.
Abstract: These days, the importance of energy consumption has led scientists to optimize thermal devices. One of the solutions proposed for this purpose is using solid nanoparticles to amend the thermal properties of conventional fluids. Adding the nanoparticles into the foundation fluids results in an improvement in the fluid properties (thermal conductivity, viscosity, etc.). Nanofluid (NF) has been drawing attention in various engineering applications in the past decade due to its superior heat transfer characteristics than the conventional working fluid. In recent years, the researchers have focused on adding two or more nanoparticles into foundation fluids, known as hybrid nanoparticles. Hybrid nanofluids (HNFs) suggest a more appropriate heat transfer performance and thermophysical features than the conventional heat transfer fluids (ethylene glycol, water and oil) and even NFs with single nanoparticles. It was proven that HNF can be an alternative to the single NF, since it can provide more heat transfer enhancement, particularly in the context of the solar energy, electromechanical, HVAC, electromechanical and automobile. In the current research, the properties, preparation and stability of HNFs are investigated. Also, some models and correlations for predicting HNFs properties are presented.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the thermal and entropy properties of a non-Newtonian Casson nanofluid in terms of its thermal transport as well as its entropy.