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Nanofluids: Synthesis, Properties and Applications
Abstract
As an emerging research field, nanofluids have sparked immense interest from researchers around the world and have been a subject of intensive research in recent years. Because of their fascinating thermophysical properties and heat transfer performances, as well as enormous potential applications, nanofluids are considered the next generation heat transfer fluids. This book covers a wide range of topics from preparation methodology, properties, and theories to applications of nanofluids. In addition to the state-of-the-art reviews and analysis on the key areas of nanofluids including thermophysical and heat transfer properties of carbon nanotube and magnetic nanofluids, viscosity of metal oxide nanofluids and pool boiling of nanofluids, this book presents extensive experimental and theoretical research efforts on thermal conductivity, viscosity, convective heat transfer, capillary wetting, and transport properties of nanofluids. Studies on the application of nanofluids in droplet-based microfluidic technology are presented. Another new area of nanofluid-based optical engineering is explored in this book. It also introduces a new class of nanofluids named-ionanofluids. Featuring contributions from some of the leading researchers in the field, this book is a unique reference source and an invaluable guide to scientists, researchers, engineers, industrial people, graduate and postgraduate students, as well as academicians across the science and engineering disciplines.
... Nanofluids have unique properties that have been studied for over 25 years. They are currently being used or targeted on for use in various biomedical, cosmetic, and thermophysical technologies, as well as in the creation of advanced materials, in tribology, pharmacology, etc. [1][2][3][4][5][6][7]. Since the viscosity is a crucial factor for the potential applications of nanofluids, it has been extensively investigated. ...
... Since the viscosity is a crucial factor for the potential applications of nanofluids, it has been extensively investigated. It has been experimentally established that the viscosity of nanofluids is significantly higher than that of conventional coarse dispersed fluids [1,[8][9][10][11]. Additionally, the viscosity of nanofluids depends not only on the concentration but also on size and material of the nanoparticles [1,[8][9][10][11][12]. ...
... It has been experimentally established that the viscosity of nanofluids is significantly higher than that of conventional coarse dispersed fluids [1,[8][9][10][11]. Additionally, the viscosity of nanofluids depends not only on the concentration but also on size and material of the nanoparticles [1,[8][9][10][11][12]. With increasing the size of nanoparticles, the viscosity of the nanofluid decreases. ...
... In most of the applications traditional thermal fluids such as water and oils are used, and inherently low thermal properties of these fluids are the main barrier for the development of advanced heat transfer systems with improved performance [1]. Therefore, it was found that mixing nanoparticles of metallic or non-metallic with such common thermal fluids can result in enhancing thermal properties and features [2][3][4][5][6] and such mixture of nanoparticles and fluids are widely known as ''nanofluids'' that can be used to improve the heat transfer performance in thermal systems [7,8]. So far, diverse kinds of nanofluids have been used in literature for experimental and numerical investigations with various thermophysical properties [9,10]. ...
... Thermal conductivity and thermal diffusivity are considered the key elements responsible for assessing the heat transfer performance of the nanofluids, where enhancing those properties leads to a better heat transfer efficiency [7,[11][12]. Thermal conductivity of nanofluids has been investigated for different types of nanoparticles and their concentrations [2,9]. However, there is still a lack of investigations on some types of nanofluids regarding the nanoparticle types and the used base fluids, as well as an accurate investigation considering both thermal conductivity and thermal diffusivity for their optimum performance in applications. ...
... This behavior is considered anomalous because it cannot be fully explained by existing theories of heat transport in conventional fluids. The references to nanofluids can be found in books by Das et al. [6], Kandelousi et al. [7], Shenoy et al. [8], and Sheikholeslami [9]. ...
The hybrid nanofluids are effective in terms of cooling where the range of temperature is high and includes a significant range of thermal applications, such as cooling electrical equipment, heat exchangers, automotive industry, heat pipes, manufacturing industry, and solar energy. As a result of these facts, this particular research emphasizes on the silver- titanium oxide /water hybrid nanofuid flow through an exponentially stretching sheet. The impacts such as viscous dissipation, magneto hydrodynamics, porosity, thermal radiation and heat generation have been also taken into account. By utilizing non-dimensional quantities and similarity functions, the flow model is transformed and simplified to a system of ordinary differential equations. With the help of the numerical method Runge-Kutta with shooting technique in Matlab script, the desired system is solved. It has been discovered that stronger the porosity parameter raises the temperature while diminishing the velocity. It additionally emphasizes that augmentations in the magnetic parameter, Eckert number, radiation parameter, and volume percentage of T i O 2 and A g nanoparticles proportional to the temperature profile. The results demonstrate satisfactory congruence’s when compared to the current literature.
... Another method to improve the efficiency which includes thermal fluids with increased thermophysical properties of nanofluids. The traditional fluids utilized in the applications of heat transfer were replaced by nanofluids, which were considered to be of high capacity due to their high thermal conductivity [7]; they are commonly utilized in the applications of heat transfer for the purpose of increasing the energy effectiveness of numerous devices [8][9][10]. Different types of thermal solar collectors can be employed to convert solar radiation into thermal energy for heating and cooling applications. ...
In this paper, the effect of using different configurations of absorber plate, including one line finned flat absorber and two lines finned absorber plate, on the thermal performance of a flat plate – double passing solar air heater was investigated experimentally. L- shape fins are soldered on the absorber plate to roughen the absorber plate and generate vortices to enhance the heat transfer between the working fluid (air) and absorber plate to improve the thermal efficiency. The outdoor experimental test was carried out during February and May under the weather conditions of Baghdad city (Longitude 33.3 N and Latitude 44.44 E). The results show that the air temperature is 48 °C, 47.5°C, and 58.5 °Cat an air velocity of 1.7 m/s for a single line of fins which increased to 52 °C, 57.5 °C, and 66 °C at air velocity of 0.9 m/s for two lines of fins. The efficiency is increased by 28% for one line of fins and 66% for two lines of fins at an air velocity of 0.9 m/s while increased by 27% for one line of fins and 51% for two lines of fins at an air velocity of 1.7 m/s. The average exergy destruction rate increases by 37.6%, 60.6%, and 68.66% for the absorber plate, working fluid, and glass cover, respectively, for velocity increase from 0.9 m/s to 1.9 m/s. The exergy efficiency increased by 24.1% when the velocity increased from 0.9 m/s to 1.9 m/s.
... Nanofluids have a lot of thermophysical attributes like improved heat conductivity, heat diffusivity, and viscosity as opposed to their common base liquids, such as oil or water. Nanofluids applications embrace mass and thermal transportation in engineering and industrial appliances, coolant in automotive electronics, such as microscale, microchips, etc. [1]. The idea of the nanofluid was introduced for the first time by [2] in ninetieth century for enhance the heat transfer rate. ...
The evolution of nanofluids is important for improving the thermal conductivity of base fluids. The influence of thermal radiation and thermal stratification on the magnetohydrodynamic micropolar nanofluid flow through a shrinking sheet with a prescribed heat flux on the surface has been examined. The most important parts of this study are the effects of magnetohydrodynamic microrotation, thermal radiation, the magnetic field, and the Cattaneo-Christov heat flux model. The efficiency of nanoparticles, heat, and mass transference rates are influenced by the magnetic field pattern, the characteristics of the source of heat, thermal radiation, and the dispersion of volume fraction. The partial differentials are transformed into the set of nonlinear differential equations through boundary layer estimations and similarity substitutions and then computed with the use of a variational finite element procedure. A MATLAB code has been developed to assess parametric simulations for reduced skin friction factor, micro-rotation, fluid velocity, heat transfer rate, and thermal properties for the Glariken formulation. The temperature field declined due to increasing values of the thermal stratification parameter and the heat transfer rate accelerated. There is a strong link between the two sets of results, which shows that the finite element method used here is accurate.
... Nanofluids can be simply seen as a base fluid (water, oil, ethylene glycol, etc.) in which nanosized particles (metals, oxides, carbon nanotubes, etc.) are in a colloidal suspension [1][2][3][4]. Since the thermal conductivity of the nanoparticles is higher than the base fluid, heat transfer is significantly enhanced compared to conventional base fluids. ...
This work deals with a numerical investigation of a hydrodynamic–elastic problem within the framework of a double enclosure solar collector technological configuration. The solar collector presents two enclosures separated by an elastic absorber wall. The upper enclosure is filled with air, whereas the lower one is filled with Fe3O4/water nanofluid. The mathematical model governing the thermal and flow behaviors of the considered nanofluid is elaborated. The effects of imposed hot temperatures, the Rayleigh number and air pressure on the nanofluid’s temperature contours, velocity magnitude distribution, temperature evolution, velocity magnitude evolution and Nusselt number evolutions are numerically investigated. The numerical results show and assess how the increase in the Rayleigh number affects convective heat transfer at the expense of the conductive one, as well as how much the Nusselt number and the nanofluid velocity magnitude and temperature are affected in a function of the imposed hot temperature type (uniformly or right-triangular distributed on the elastic absorber wall). Moreover, the results evaluate how increases in the air pressure applied on the elastic absorber wall affects the nanofluid’s temperature distribution.
... On addressing the challenges, nanoparticles (NPs) are believed to possess promising potentials, thanks to their ultra-small size, high surface-tovolume ratio, low costs, and environmental friendliness [8][9][10]. Utilizing nanofluids, namely flooding liquids with NPs, has been a focus of interest in petroleum research and applications starting from the end of the last century [11][12][13][14]. ...
Janus nanoparticles (NPs) hold great potential in enhanced oil recovery (EOR), although the mechanism remains unclear. In the study, the displacement dynamics of trapped oil in the rough channel by Janus NPs are unraveled through atomistic modeling. The results indicate that Janus NPs with large polar faces significantly recover more oil from the nano-pocket (nano groove of the surface). The structure of adsorbed NPs on the wall of oil-trapping nano-pockets strongly causes the local wettability alteration, which ultimately determines the oil recovery. The crucial events in oil recovery by Janus NPs, termed ‘adsorption invasion process’, are identified, which comprise of anchoring onto the surface, pinning at the edge, and entering inside the pocket. The controlling factors are further detailed, including identification of the residual oil, displacement pressure, and the geometry of the oil-water interface inside nano-pockets. With the proposed analysis, the “huff-n-puff” mode is verified as the optimized application method for Janus NPs. For the first time, our results bring to light the dynamic wettability alteration on the rough surface by Janus NPs from atomistic insights. The findings reveal the intrinsic EOR mechanism of Janus NPs, which could guide the design and application of Janus NPs in EOR.
... On the one hand, their small size allows them to transport into the small channels. On the other hand, their high surface energy and reactivity are conducive to modify the properties of fluids and rock surfaces, thereby improving oil displacement [13,14]. So far, NPs have achieved highly encouraging results in both laboratory and field experiments [12]. ...
It is well accepted that nanofluids have great potential in enhanced oil recovery (EOR). However, the EOR mechanisms by nanofluids largely remain elusive. In the study, the displacement dynamics of residual oil trapped in rough channels by different nanofluids under varied injection pumping forces are investigated by atomistic modeling. Our results indicate that both hydrophilic nanoparticles (NPs) and Janus NPs have highly obvious oil displacement effects. Specifically, hydrophilic NPs increase the viscosity and enlarge the sweeping scope of injected fluid, while Janus NPs favor either staying at the oil–water interface to reduce the interfacial tension or adsorbing onto the convex surface. Under the drag of the injecting flux, Janus NPs displace trapped oil molecules and alter the local surface wettability by sliding along the surface. In contrast, hydrophobic NPs are prone to migrate into the oil phase, which not only reinforces the trapping effect of the oil molecules by the rough surface but also poses a risk of channel blockage. Despite that the oil displacement effect of all the injection fluids is found to be less significant with low pumping force, the Janus NPs are able to maintain a stable oil displacement performance under low pumping force thanks to their sufficiently long contact time with the oil phase. Furthermore, analysis on capillary number indicates that Janus NPs have outstanding application potentials in reservoirs under realistic flooding conditions. Our findings provide atomistic insights into the mechanism of nanofluids in EOR and shed light on the selection and optimization of NPs.
... Nanofluids have a lot of thermophysical attributes like improved heat conductivity, heat diffusivity, and viscosity as opposed to their common base liquids, such as oil or water. Nanofluids applications embrace mass and thermal transportation in engineering and industrial appliances, coolant in automotive electronics, such as microscale, microchips, etc. [1]. The idea of the nanofluid was introduced for the first time by Choi [2] in 1995 for enhance the heat transfer rate. ...
Bioconvection phenomena for MHD Williamson nanofluid flow over an extending sheet of irregular thickness are investigated theoretically, and non-uniform viscosity and thermal conductivity depending on temperature are taken into account. The magnetic field of uniform strength creates a magnetohydrodynamics effect. The basic formulation of the model developed in partial differential equations which are later transmuted into ordinary differential equations by employing similarity variables. To elucidate the influences of controlling parameters on dependent quantities of physical significance, a computational procedure based on the Runge–Kutta method along shooting technique is coded in MATLAB platform. This is a widely used procedure for the solution of such problems because it is efficient with fifth-order accuracy and cost-effectiveness. The enumeration of the results reveals that Williamson fluid parameter λ, variable viscosity parameter Λμ and wall thickness parameter ς impart reciprocally decreasing effect on fluid velocity whereas these parameters directly enhance the fluid temperature. The fluid temperature is also improved with Brownian motion parameter Nb and thermophoresis parameter Nt. The boosted value of Brownian motion Nb and Lewis number Le reduce the concentration of nanoparticles. The higher inputs of Peclet number Pe and bioconvection Lewis number Lb decline the bioconvection distribution. The velocity of non-Newtonian (Williamson nanofluid) is less than the viscous nanofluid but temperature behaves oppositely.
This book features a dozen high-quality research studies and reviews on different types of nanofluids and their important topics related to thermophysical and electrical properties, as well as convective and boiling heat transfer characteristics, contributed by renowned researchers around the world. It is expected to be a useful resource for related industrial professionals and researchers in this emerging and popular field of nanofluids.
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