scholarly journals Critical Review on Nanofluids: Preparation, Characterization, and Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-22 ◽  
Author(s):  
Mohamoud Jama ◽  
Tejvir Singh ◽  
Seifelislam Mahmoud Gamaleldin ◽  
Muammer Koc ◽  
Ayman Samara ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
High Performance ◽  
Two Phase ◽  
Heat Transfer Fluids ◽  
Thermal And Electrical Properties ◽  
Improve Heat Transfer ◽  
The Stability ◽  
New Generation

Heat transfer fluids are a crucial parameter that affects the size and costs of heat exchangers. However, the available coolants like water and oils have low thermal conductivities, which put many limitations to the development of heat transfer to achieve high performance cooling. The need for development of new classes of fluids which enhance the heat transfer capabilities attracted the attention of many researchers. In the last few decades, modern nanotechnology developed nanoparticles, which have unique thermal and electrical properties that could help improve heat transfer using nanofluids. A “nanofluid” is a fluid with suspended fine nanoparticles which increases the heat transfer properties compared with the original fluid. Nanofluids are considered a new generation of heat transfer fluids and are considered two-phase fluids of liquid solid mixtures. The efficiency of the fluid could be improved by enhancing its thermal properties, especially the thermal conductivity, and it is expected that the nanofluids will have a greater thermal conductivity than the base fluids. This paper reviews the preparation of metallic and nonmetallic nanofluids along with the stability of the produced nanofluids. Physical and thermal properties as well as a range of applications are also discussed in detail.

scholarly journals Review of water-nanofluid based photovoltaic/thermal (PV/T) systems

2019 ◽  
Vol 9 (1) ◽  
pp. 134 ◽  
Author(s):  
Nur Farhana Mohd Razali ◽  
Ahmad Fudholi ◽  
Mohd Hafidz Ruslan ◽  
Kamaruzzaman Sopian
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Solar Energy ◽  
Optical Filter ◽  
Heat Transfer Fluid ◽  
Nanoparticles Concentration ◽  
Improve Heat Transfer ◽  
New Generation ◽  
To Receive ◽  
T System

<span lang="EN-US">Solar energy is secure, clean, and available on earth throughout the year. The PV/T system is a device designed to receive solar energy and convert it into electric/thermal energy. Nanofluid is a new generation of heat transfer fluid with promising higher thermal conductivity and improve heat transfer rate compared with conventional fluids. In this review, the recent studies of PV/T using nanofluid is discussed regarding basic concept and theory PV/T, thermal conductivity of nanofluid and experimentally and theoretically study the perfromance of PV/T using nanofluid. A review of the literature shows that many studies have evaluated the potential of nanofluid as heat transfer fluid and optical filter in the PV/T system. The preparations of nanofluid play an essential key for high stability and homogenous nanofluid for a long period. The thermal conductivity of nanofluid is depending on the size of nanoparticles, concentration and preparation of nanofluids.</span>

Studies on few Water Based Nanofluids Behavior at Heating

2015 ◽  
Vol 1128 ◽  
pp. 384-389
Author(s):  
Madalina Georgiana Moldoveanu ◽  
Alina Adriana Minea
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Unsolved Problem ◽  
Volume Fraction ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Heat Transfer Fluids ◽  
Surface Areas ◽  
Water Based ◽  
Semi Empirical

Application of nanoparticles provides an effective way of improving heat transfer characteristics of fluids. Particles less than 100 nm in diameter exhibit different properties from those of conventional solids. Compared with micron-sized particles, nanophase powders have much larger relative surface areas and a great potential for heat transfer enhancement. Some researchers tried to suspend nanoparticles into fluids to form high effective heat transfer fluids. Some preliminary experimental results showed that increase in thermal conductivity of approximately 60% can be obtained for some nanofluids consisting of water and 5 vol% CuO nanoparticles. So, the thermal conductivity of nanofluid was found to be strongly dependent on the nanoparticle volume fraction. So far it has been an unsolved problem to develop a sophisticated theory to predict thermal conductivity of nanofluids, although there are some semi empirical correlations to calculate the apparent conductivity of two-phase mixture. In this article, several correlations for predicting the nanofluid thermal conductivity will be compared and results will be discussed for three water based nanofluids.

Preparation and Characterization of Rutile Titania Nanofluids Stabilized in Different Surfactants Base Fluids

2020 ◽  
Vol 10 (5) ◽  
pp. 682-695
Author(s):  
Radwa A. El-Salamony ◽  
Mohamed Z. Abd-Elaziz ◽  
Rania E. Morsi ◽  
Ahmed M. Al-Sabagh ◽  
Saad S.M. Hassan
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Performance ◽  
Sodium Dodecyl ◽  
Transfer Performance ◽  
Heat Transfer Fluids ◽  
Transmission Electron ◽  
Performance Of Heat Transfer ◽  
Rutile Titania ◽  
The Stability

Background: Improvement of conventional heat transfer fluids for achieving higher energy efficiencies in thermal equipment is a key parameter to conserve energy in industries. The heat transfer fluids such as water, oil and ethylene glycol greatly suffer low heat transfer performance in industrial processes. There is a need to develop new types of heat transfer fluids that are more effective in terms of heat transfer performance. Nanofluids enhance thermal conductivity and improve the thermal performance of heat transfer systems. Methods: New titania nanofluid samples consisting of 0.0625 to 1% TiO2 nanoparticles were prepared and characterized. The method of preparation was based on prior precipitation of TiO2 from an ammoniacal solution of pH 9 and calcination at 900°C. Solubilization, homogenization and stabilization of the of the nanoparticles were performed by sonication in the presence of sodium dodecyl sulfate (SDS) anionic surfactant and cetyltrimethylammonium bromide (CTAB) cationic surfactant. Results: This treatment was also utilized to increase the stability and improve the thermal properties of the fluid. Conclusion: Several characterization techniques including measurements of hydrodynamic size distribution, zeta potential, transmission electron microscopy (TEM), viscosity, density, specific heat, thermal conductivity, and sedimentation photo capturing were used to measure and confirm the stability and sedimentation rate of the prepared nanofluids.

Analytical Technique for Estimating the Termophysical Properties of Hybrid Nanofluids

2017 ◽  
Vol 1143 ◽  
pp. 207-213
Author(s):  
Madalina Georgiana Moldoveanu ◽  
Tudor Mihai Simionescu ◽  
Alina Adriana Minea ◽  
Adrian Dima
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
High Performance ◽  
Solid Particles ◽  
Drilling Fluids ◽  
Distilled Water ◽  
Worst Case ◽  
Analytical Technique ◽  
Heat Transfer Fluids ◽  
High Concentrations

Over the past years, the development of functional heat transfer fluids by compounding different substances or different phases of matter (solid, liquid, or gas) has raised increasing interest in view of their potential applications in technologies. In particular, the nanofluids in which the solid particles (<100 nm or smaller) are incorporated as the dispersed phase in the suspensions, are currently focus of great attention because of their perspective potentials as high-performance heat transfer fluids. The potential advantage of utilizing the nanofluid lies mainly in its drastic increase in the thermal conductivity. This paper presents a study of the thermophysical characteristics of some nanofluids and their hybrids. General correlations for the effective thermal conductivity and viscosity of nanofluids are used for this analysis. Regarding the importance of thermophysical properties of water based drilling fluids, the effects of insertion of two oxides in an alumina-water nanofluid on the thermal conductivity, viscosity and density of distilled water were investigated. According to the results, viscosity and density of the nanofluids increased with the concentration. At high concentrations, the least increase in the viscosity of distilled water by adding the nanomaterials is related to H2 (8.2% increase at 1.0 wt.%). As the results show, increase in the density of distilled water by adding the nanomaterials is insignificant, that in the worst case it did not exceed 0.9%. The least increase in the density of base fluid at high concentrations was for H1.

Nanofluids: From Vision to Reality Through Research

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Stephen U. S. Choi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Future Directions ◽  
Fundamental Limits ◽  
Heat Transfer Fluids ◽  
Size Dependent ◽  
New Class ◽  
Scientists And Engineers ◽  
Basic And Applied Research

Nanofluids are a new class of nanotechnology-based heat transfer fluids engineered by dispersing and stably suspending nanoparticles with typical length on the order of 1–50 nm in traditional heat transfer fluids. For the past decade, pioneering scientists and engineers have made phenomenal discoveries that a very small amount (<1 vol %) of guest nanoparticles can provide dramatic improvements in the thermal properties of the host fluids. For example, some nanofluids exhibit superior thermal properties such as anomalously high thermal conductivity at low nanoparticle concentrations, strong temperature- and size-dependent thermal conductivity, a nonlinear relationship between thermal conductivity and concentration, and a threefold increase in the critical heat flux at a small particle concentration of the order of 10 ppm. Nanofluids are of great scientific interest because these unprecedented thermal transport phenomena surpass the fundamental limits of conventional macroscopic theories of suspensions. Therefore, numerous mechanisms and models have been proposed to account for these unexpected, intriguing thermal properties of nanofluids. These discoveries also show that nanofluids technology can provide exciting new opportunities to develop nanotechnology-based coolants for a variety of innovative engineering and medical applications. As a result, the study of nanofluids has emerged as a new field of scientific research and innovative applications. Hence, the subject of nanofluids is of great interest worldwide for basic and applied research. This paper highlights recent advances in this new field of research and shows future directions in nanofluids research through which the vision of nanofluids can be turned into reality.

Preparation and Characterisation of Graphene Nanofluid: To Be Used As Coolant

2020 ◽  
Author(s):  
Senthil Kumar Velukkudi Santhanam ◽  
Dolly Austen Thomas ◽  
Mystica Augustine Michael Duke ◽  
Viswanathan Doraiswamy
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Base Fluid ◽  
Solid Phase ◽  
Nano Particles ◽  
Planar Geometry ◽  
Phase System ◽  
Transfer Coefficients ◽  
Two Phase ◽  
The Stability

Abstract In the recent years, nanofluids embarked as a new class of fluids with improved thermophysical properties such as thermal conductivity, thermal diffusivity, viscosity, and convective heat transfer coefficients thus promoting better heat transfer. Nanofluids consists of two-phase system where the nano sized solid phase (nanoparticles) is dispersed into a base fluid. Graphene is a material which has two-dimensional planar geometry with thermal conductivity of the order of 5000 W/mK. Nanoparticles in the form of thin flakes as small as 50 nm, 100 nm has been used in this study. Two step technique is the used method for preparing nanofluids. Inclusion of additives in small quantity, enhance the durability of the nano particles inside the conventional base fluids. The stability of the solid nano particles inside the conventional base fluid is increased by using surfactants. The heat transfer capacity and stability of the fluids are considered as the basic properties for investigation. The nanofluids characterization studies were drawn from the SEM, XRD and thermal conductivity results. Hot wire method was used to determine the thermal conductivity of the nanofluids. The preparation and properties of graphene based nanofluids which can be used as coolant are studied in this work.

Heat Transfer Characteristics of 1-D Ferromagnetic Nanofluid

2020 ◽  
Author(s):  
Ali Imran Shiave ◽  
Ram Mohan
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
High Performance ◽  
High Surface ◽  
Electronic Devices ◽  
Stable Suspension ◽  
Mineral Oils ◽  
Increase Productivity ◽  
Cooling Media

Abstract Improving the efficiency of the cooling medium to increase productivity and decrease energy consumption is one of the biggest challenges in the current world. Industries, including transportation, manufacturing, and electronic devices, etc. need efficient thermal management and can benefit from the use of efficient cooling media. Industrial coolants i.e. water, ethylene glycol (EG), or mineral oils have long been used for heat transport though the low thermal conductivity (TC) of these coolants has made them inefficient options for high-performance operations. Metal nanofluids can be potential candidates to replace these inefficient coolants because of their superior thermal properties such as high thermal conductivity, diffusivity, and heat transfer coefficient compared to the base fluids. Nanofluids are a stable suspension of nanoparticles in base media which can offer better thermal conductivity and efficiency. However, preparing stable suspension is one of the major challenges of preparing nanofluids as nanoparticles can aggregate faster over time because of their high surface energy which in turn can have an adverse effect on thermal properties. So far, most research investigations have been done on 0-D nanofluids whereas 1-D nanostructure-based nanofluid study is still very limited. In this work, we have developed a suitable route to prepare novel water-based Cobalt nanowire nanofluids and studied their thermal conductivities. Our study shows that the prepared nanofluid is stable and the thermal conductivity is increased by up to 8.5% compared to base fluid (water).

A Brief Review on Thermal Behaviour of PANI as Additive in Heat Transfer Fluid

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
A.G.N. Sofiah ◽  
◽  
M. Samykano ◽  
S. Shahabuddin ◽  
K. Kadirgama ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Conducting Polymers ◽  
Volume Fraction ◽  
Corrosion Property ◽  
Environmental Stability ◽  
Heat Transfer Fluid ◽  
Thermal Engineering ◽  
Engineering System ◽  
Heat Transfer Fluids

Since a decade ago, investigation on nanofluids has grown significantly owing to its enhanced thermal properties compared to conventional heat transfer fluids. This engineered nanofluid has been widely used in the thermal engineering system to improve their energy consumption by improving the thermal efficiency of the system. The addition of nano-size particles as additives dispersed in the base fluids proved to significantly either improve or diminish the behaviour of the base fluids. The behaviour of the base fluid highly depends on the properties of the additives material, such as morphology, size, and volume fraction. Among the variety of nanoparticles studied, the conducting polymers have been subject of high interest due to its high environmental stability, good electrical conductivity, antimicrobial, anti-corrosion property and significantly cheap compared to other nanoparticles. As such, the main objective of the present review is to provide an overview of the work performed on thermal properties performance of conducting polymers based nanofluids.

Study of thermal conductivity of nanofluids for the application of heat transfer fluids

2007 ◽  
Vol 455 (1-2) ◽  
pp. 66-69 ◽  
Author(s):  
Dae-Hwang Yoo ◽  
K.S. Hong ◽  
Ho-Soon Yang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Fluids

Heat Exchange Between a Tube and Water-Saturated Soil

1986 ◽  
Vol 108 (4) ◽  
pp. 298-302 ◽  
Author(s):  
C. A. van der Star ◽  
G. A. M. van Meurs ◽  
C. J. Hoogendoorn
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Saturated Soil ◽  
Mutual Distance ◽  
Tube Material ◽  
Surrounding Water ◽  
Analytical Approximations ◽  
Water Saturated ◽  
Regional Groundwater

The heat transfer between a cylinder and the surrounding water-saturated soil is studied numerically. Parameters which influence this heat transfer are thermal properties of the soil, dimension and thermal conductivity of the tube material, and a regional groundwater flow. The results are compared to analytical approximations. When two tubes are present, their mutual distance is also such a parameter.

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