Showing papers on "Nanofluid published in 2015"
TL;DR: In this paper, a review summarizes recent researches on synthesis, thermophysical properties, heat transfer and pressure drop characteristics, possible applications and challenges of hybrid nanofluids, and showed that proper hybridization may make the hybrid nanoparticles very promising for heat transfer enhancement, however, lot of research works are still needed in the fields of preparation and stability, characterization and applications to overcome the challenges.
Abstract: Researches on the nanofluids have been increased very rapidly over the past decade. In spite of some inconsistency in the reported results and insufficient understanding of the mechanism of the heat transfer in nanofluids, it has been emerged as a promising heat transfer fluid. In the continuation of nanofluids research, the researchers have also tried to use hybrid nanofluid recently, which is engineered by suspending dissimilar nanoparticles either in mixture or composite form. The idea of using hybrid nanofluids is to further improvement of heat transfer and pressure drop characteristics by trade-off between advantages and disadvantages of individual suspension, attributed to good aspect ratio, better thermal network and synergistic effect of nanomaterials. This review summarizes recent researches on synthesis, thermophysical properties, heat transfer and pressure drop characteristics, possible applications and challenges of hybrid nanofluids. Review showed that proper hybridization may make the hybrid nanofluids very promising for heat transfer enhancement, however, lot of research works is still needed in the fields of preparation and stability, characterization and applications to overcome the challenges.
846 citations
TL;DR: In this paper, the effect of thermal radiation on magnetohydrodynamics nanofluid flow between two horizontal rotating plates is studied and the significant effects of Brownian motion and thermophoresis have been included in the model of Nanofluide.
700 citations
TL;DR: In this paper, the effects of Brownian motion on the effective viscosity and thermal conductivity of nanofluid were investigated. And the results were presented graphically in terms of streamlines, isotherms and isokinetic energy.
556 citations
TL;DR: In this article, the effect of nanoparticle volume fraction on thermal conductivity and dynamic viscosity of Ag-MgO/water hybrid nanofluid with the particle diameter of 40(mgO) and 25(Ag) nm was investigated.
461 citations
TL;DR: In this article, a hybrid nanofluid consisting of MoS2 nanoparticles with good lubrication effect and CNTs with high heat conductivity coefficient is investigated for Ni-based alloy grinding.
Abstract: A nanofluid minimum quantity lubrication with addition of one kind of nanoparticle has several limitations, such as grinding of difficult-to-cutting materials Hybrid nanoparticles integrate the properties of two or more kinds of nanoparticles, thus having better lubrication and heat transfer performances than single nanoparticle additives However, the use of hybrid nanoparticles in nanofluid minimum quantity lubrication grinding has not been reported This study aims to determine whether hybrid nanoparticles have better lubrication performance than pure nanoparticle A hybrid nanofluid consisting of MoS2 nanoparticles with good lubrication effect and CNTs with high heat conductivity coefficient is investigated The effects of the hybrid nanofluid on grinding force, coefficient of friction, and workpiece surface quality for Ni-based alloy grinding are analyzed Results show that the MoS2/CNT hybrid nanoparticles achieve better lubrication effect than single nanoparticles The optimal MoS2/CNT mixing ratio and nanofluid concentration are 2:1 and 6 wt%, respectively
365 citations
TL;DR: In this article, a mathematical model is analyzed in order to study the natural convection boundary layer flow along an inverted cone, where the shape of nanosize particles on entropy generation with based fluid is considered.
353 citations
TL;DR: In this paper, the effect of adding molybdenum disulfide nanoparticles with a particle size of 50nm was studied for a numerical control precision surface grinder for plain grinding on a 45 steel workpiece.
344 citations
TL;DR: The preparation of nanofluids by various techniques, methods of stabilization, stability measurement techniques, thermal conductivity and heat capacity studies, proposed mechanisms of heat transport, theoretical models on thermal Conductivity, factors influencing k and the effect of nanoinclusions in PCM are discussed in this review.
341 citations
TL;DR: In this article, two new correlations for predicting the thermal conductivity of studied hybrid nanofluids, in terms of solid concentration and temperature, are proposed that use an artificial neural network (ANN) and are based on experimental data.
341 citations
TL;DR: In this article, the authors reported measured vapor generation efficiencies of 69% at solar concentrations of 10 sun using graphitized carbon black, carbon black and graphene suspended in water, representing a significant improvement in both transient and steady-state performance over previously reported results.
333 citations
TL;DR: In this article, the effects of variable surface heat flux and first-order chemical reaction on MHD flow and radiation heat transfer of nanofluids against a flat plate in porous medium were investigated.
TL;DR: In this article, force convection heat transfer in a lid driven semi annulus enclosure is studied in presence of non-uniform magnetic field and the calculations were performed for different governing parameters namely, the Reynolds number, nanoparticle volume fraction and Hartmann number.
TL;DR: In this paper, the effect of the squeeze number, nanofluid volume fraction, Hartmann number and heat source parameter on flow and heat transfer was investigated, and the results showed that skin friction coefficient increases with increase of the Nusselt number and Hartmann numbers but it decreases with an increase in the volume fraction.
TL;DR: In this paper, the MHD laminar boundary layer flow with heat and mass transfer of an electrically conducting water-based nanofluid over a nonlinear stretching sheet with viscous dissipation effect is investigated numerically.
TL;DR: In this article, a three-dimensional flow of couple stress nanofluid in the presence of thermophoresis and Brownian motion effects is analyzed and the energy equation subject to nonlinear thermal radiation is taken into account.
TL;DR: In this paper, the effective thermal conductivity and viscosity of nanofluid are calculated by KKL (Koo-Kleinstreuer-Li) correlation.
Abstract: In this paper magnetohydrodynamic free convection flow of CuO–water nanofluid in a square enclosure with a rectangular heated body is investigated numerically using Lattice Boltzmann Method (LBM) scheme. The effective thermal conductivity and viscosity of nanofluid are calculated by KKL (Koo–Kleinstreuer–Li) correlation. The influence of pertinent parameters such as Hartmann number, nanoparticle volume fraction and Rayleigh number on the flow, heat transfer and entropy generation have been examined. The results show that the heat transfer rate and Dimensionless entropy generation number increase with increase of the Rayleigh number and nanoparticle volume fraction but it decreases with increase of the Hartmann number.
TL;DR: In this article, a new synthesis method is introduced for decoration of silver on the functionalized graphene nanoplatelets (GNP-Ag) and preparation of nanofluids is reported.
TL;DR: In this paper, different nanofluids were developed by mixing a water base fluid with magnetic nanoparticles, and thermal properties such as thermal conductivity and viscosity of the obtained nanoparticles were investigated.
Abstract: The addition of nanoparticles to a base fluid is one of the significant issues to enhance heat transfer. In this study, different nanofluids were developed by mixing a water base fluid with magnetic nanoparticles. Thermophysical properties such as thermal conductivity and viscosity of the obtained nanofluid were investigated. The effect of different nominal diameters of nanoparticles and concentrations of nanoparticles on the thermal conductivity and viscosity of nanofluids have been examined. Three different diameters of magnetic nanoparticles (about 37 nm, 71 nm, and 98 nm) have been tested in this experimental investigation. Experimental results indicate that thermal conductivity increases as volume fraction increases, and thermal conductivity of the nanofluid increases with a decrease of nanoparticle’s size. Moreover, the nanofluid dynamics viscosity ratio increases with an increase in particle concentration and nanoparticle’s diameter. This paper identifies several important issues that should be considered in future work.
TL;DR: In this paper, the performance of single basin single slope solar still with and without water nanofluid was compared and two experimental stills of the same basin area have been fabricated and tested with water and different nanophluids simultaneously.
TL;DR: In this article, the experimental and numerical results for the thermal conductivity, viscosity, specific heat and the heat transfer coefficient reported by several authors are presented, with and without the application of nano-fluids.
TL;DR: Magnetic nanofluids (MNFs) are suspensions which are comprised of a non-magnetic base fluid and magnetic nanoparticles and can be controlled by applying magnetic fields as mentioned in this paper.
TL;DR: In this article, the effect of spatially variable magnetic field on ferrofluid flow and heat transfer is investigated and the combined effects of ferrohydrodynamic and magnetohydrodynamic have been taken into account.
Abstract: Effect of spatially variable magnetic field on ferrofluid flow and heat transfer is investigated. The enclosure is filled with Fe3O4–water nanofluid. Control volume based finite element method (CVFEM) is applied to solve the governing equations. The combined effects of ferrohydrodynamic and magnetohydrodynamic have been taken into account. The influences of Magnetic number, Hartmann number, Rayleigh number and nanoparticle volume fraction on the flow and heat transfer characteristics have been examined. Results show that enhancement in heat transfer decrease with increase of Rayleigh number while for two other active parameters different behavior is observed. Also it can be concluded that Nusselt number is an increasing function of Magnetic number, Rayleigh number and nanoparticle volume fraction while it is a decreasing function of Hartmann number.
TL;DR: In this paper, the authors present an updated review of properties of nanofluids, such as physical (thermal conductivity) and rheological properties, with emphasis on their heat transfer enhancement characteristics.
TL;DR: In this article, a CFD modeling of a horizontal circular tube was presented to investigate the effect of nanofluids on laminar forced convective heat transfer, and the results showed that the proposed mixture model revealed a better agreement with the experimental data.
TL;DR: In this article, the effects of wall slip velocity and temperature jump of the nanofluid were studied for the first time by using lattice Boltzmann method, and the results indicated that LBM can be used to simulate forced convection for the nano-fluid micro flows.
Abstract: Laminar forced convection heat transfer of water–Cu nanofluids in a microchannel was studied utilizing the lattice Boltzmann method (LBM). The entering flow was at a lower temperature compared to the microchannel walls. Simulations were performed for nanoparticle volume fractions of 0.00 to 0.04 and slip coefficient from 0.005 to 0.02. The model predictions were found to be in good agreement with earlier studies. The effects of wall slip velocity and temperature jump of the nanofluid were studied for the first time by using lattice Boltzmann method. Streamlines, isotherms, longitudinal variations of Nusselt number, slip velocity and temperature jump as well as velocity and temperature profiles for different cross sections were presented. The results indicate that LBM can be used to simulate forced convection for the nanofluid micro flows. Moreover, the effect of the temperature jump on the heat transfer rate is significant. Also, the results showed that decreasing the values of slip coefficient enhances the convective heat transfer coefficient and consequently the Nusselt number (Nu) but increases the wall slip velocity and temperature jump values.
TL;DR: In this paper, water-based nanofluids have been used to enhance the heat transfer performance of a car radiator by adding ZnO nanoparticles to base fluid in different volumetric concentrations (0.01, 0.08), 0.2% and 0.3%).
TL;DR: In this article, the authors made use of nanofluid as metal working fluid (MWF) by adding nano-particles to the base fluid to alter the lubricating properties by reducing the friction.
Abstract: Nanofluid, fluid suspensions of nanometer sized particles are revolutionizing the field of heat transfer area. Addition of nano-particles to the base fluid also alters the lubricating properties by reducing the friction. In grinding process, friction between the abrasive grains and the workpiece is a key issue governing the main grinding output. It has a direct influence on grinding force, power, specific energy and wheel wear. Moreover, high friction force increases the heat generation and lead to thermal damage in the surface layer of the ground work. Hence, any effort towards the friction control will enhance the component quality significantly. In this study, nanofluid as metal working fluid (MWF) is made by adding 0.05, 0.1, 0.5 and 1% volume concentration of Al2O3 and CuO nano-particles to the water during the surface grinding of Ti–6Al–4V in minimum quantity lubrication (MQL) mode. Surface integrity of ground surface, morphology of the wheel, and chip formation characteristics are studied using surface profilometer, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and stereo zoom microscopy (SZM). Coefficient of friction was estimated On-Machine using the measured forces. The results showed that the type of nanoparticle and its concentration in base fluid and the MQL flow rate play a significant role in reducing friction. Application of nanofluid leads to the reduction of tangential forces and grinding zone temperature. The cooling effect is also evident from the short C-type chip formation. MQL application with Al2O3 nanofluid helps in effective flushing of chip material from the grinding zone, thereby solving the main problem during the grinding of Ti–6Al–4V.
TL;DR: In this article, a well dispersed ethylene glycol (EG) based nanofluids containing ZnO nanoparticles with different mass fractions between 1.75% and 10.5% were prepared by a typical two-step method.
TL;DR: It is observed that the incorporation of the alloy nanoparticles enhances the thermal conductivity of the base fluid (water) showing nanofluid application and the nitric oxide and hydroxyl radical scavenging activity shown by the nanoparticles promise the potential application in biomedical field.
TL;DR: In this article, the impacts of different nanofluids of zirconium dioxide (ZrO2), calcium carbonate (CaCO3), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2), magnesium oxide (MgO), aluminum oxide (Al2O3), cerium oxide (CeO2) and carbon nanotube (CNT) on the wettability of carbonate rocks were investigated.
Abstract: Nanofluids have been recently proposed as new chemical agents for enhanced oil recovery from oil reservoirs. Various nanofluids have been studied in that regard and reported in the literature, verifying the capability of nanostructured materials in enhancing the oil recovery through alteration of rock wettability. In this study, the impacts of different nanofluids of zirconium dioxide (ZrO2), calcium carbonate (CaCO3), titanium dioxide (TiO2), silicon dioxide (SiO2), magnesium oxide (MgO), aluminum oxide (Al2O3), cerium oxide (CeO2), and carbon nanotube (CNT) on the wettability of carbonate rocks were investigated. A series of preliminary contact angle evaluations were performed to screen the nanoparticles. The performances of the selected nanofluids were evaluated by spontaneous imbibition and core flooding experiments. Results of spontaneous imbibition tests and coreflooding experiments confirm the active roles of CaCO3 and SiO2 nanoparticles for enhancing oil recovery. In addition, the effect of nanofl...