scholarly journals Enhanced Thermal Conductivity through the Development of Nanofluids

1996 ◽  
Vol 457 ◽  
Author(s):  
J. A. Eastman ◽  
U. S. Choi ◽  
S. Li ◽  
L. J. Thompson ◽  
S. Lee
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Industrial Applications ◽  
Nano Particles ◽  
Nanocrystalline Powder ◽  
Heat Transfer Fluids ◽  
New Class ◽  
Nanocrystalline Particles ◽  
Oxide Particles ◽  
Efficient Heat Transfer

ABSTRACTLow thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids required in many industrial applications. To overcome this limitation, a new class of heat transfer fluids is being developed by suspending nanocry stalline particles in liquids such as water or oil. The resulting “nanofluids” possess extremely high thermal conductivities compared to the liquids without dispersed nanocrystalline particles. For example, 5 volume % of nanocrystalline copper oxide particles suspended in water results in an improvement in thermal conductivity of almost 60% compared to water without nanoparticles. Excellent suspension properties are also observed, with no significant settling of nanocrystalline oxide particles occurring in stationary fluids over time periods longer than several days. Direct evaporation of Cu nano-particles into pump oil results in similar improvements in thermal conductivity compared to oxide-in-water systems, but importantly, requires far smaller concentrations of dispersed nanocrystalline powder.

The Thermal Conductivity and Viscosity of Non-Polar Hybrid CuO Nanofluid (CuO+ DEA + Cyclohexane) (CuO + DEA + 1-4 Dioxane)

2019 ◽  
Vol 17 (12) ◽  
pp. 965-967
Author(s):  
B. Rohini ◽  
A. Kingson Solomon Jeevaraj
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Copper Oxide ◽  
Viscosity Measurement ◽  
Nano Particles ◽  
Conductivity Measurements ◽  
Transfer Enhancement ◽  
Binary Fluid ◽  
New Class ◽  
Nano Fluid

Nano fluid is the new class of engineering fluid for the heat transfer applications. Copper Oxide (CuO) nano particles were dispersed in the binary fluid (Cyclohexane + DEA) and (1-4 dioxane + DEA) then prepared non-polar hybrid CuO nano fluid. Thermal conductivity (K ) and viscosity (η) of non-polar hybrid CuO nanofluid measured for very low concentration from 0.01 M to 0.06 M and various temperatures ranging from 298 K to 318 K. The transient hotwire method is used for the thermal conductivity measurements and viscometer is used for the viscosity measurement. As the concentration increases K decreases but it increases with the increase of temperature. η increases with the increase of concentration as well as with temperature. From the results the spectacular heat transfer enhancement occurred in the hybrid CuO nanofluid compared to the binary mixtures. The percentage increment of thermal conductivity of non-polar hybrid CuO nano fluid is of 15% to 20% and the viscosity increment is of from 18% to 25%.

scholarly journals AL2O3 Nanofluids as Heat Transfer Liquids in Automotives

2014 ◽  
pp. 206-212
Author(s):  
M. YASASWI ◽  
R.V. PRASAD ◽  
T.JAYANDA KUMAR
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ethylene Glycol ◽  
Energy Efficient ◽  
Solid Particles ◽  
Al2o3 Nanoparticles ◽  
Particle Volume ◽  
Heat Transfer Fluids ◽  
Potential Impact ◽  
Efficient Heat Transfer

The thermal conductivity of heating or cooling fluids is a very important property in the development of energy efficient heat transfer systems, which is one of the important needs of many industries. However, low thermal conductivity is a primary limitation in developing energy-efficient heat transfer fluids that are required for cooling purposes. Nanofluids are nanotechnology-based heat transfer fluids that are engineered by stably dispersing nanometer-sized (below 100nm) solid particles (such as ceramics, metals, alloys, semiconductors, nanotubes, and composite particles) in conventional heat transfer fluids (such as water, oil, diesel, ethylene glycol and mixtures) at relatively low particle volume concentrations. These suspended nanoparticles can change the transport and thermal properties of the base fluid. Adding to ethylene glycol, it has been observed that an enhancement of nearly 36 % with al2o3 nanoparticles and 40% enhancement with copper nanoparticles in the thermal conductivity. This paper focuses on some of the automotive applications such as coolant for automobiles, showcases a few of them that are believed to have the highest probability of success in this highly competitive industry and to raise the awareness on the promise of nanotechnology, its potential impact on the future of the automotive industry.

Experimental Analysis of Nanofluid Slurry Through Rectangular Porous Channel

2012 ◽  
Author(s):  
Navid O. Ghaziani ◽  
Fatemeh Hassanipour
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Porous Media ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Metallic Nanoparticles ◽  
Metal Foam ◽  
Nano Particles ◽  
Aluminum Oxide Nanoparticles ◽  
Efficient Heat Transfer

One of the limitations in evolution of energy-efficient heat transfer fluids in industrial application is their low thermal conductivity. Among the emerging heat transfer technologies of today are fluid additives based on metallic nanoparticles. Previous studies show that Matalic nano particles increase the heat transfer rate by their thermal conductivity. This experimental study investigates the heat transfer behavior of nanofluid slurry through metal foam. Using suspending Aluminum Oxide nanoparticles (AL2O3) in fluid flowing through porous medium leads to have an even greater augmentation in heat transfer rate. Metal foams (porous media) enhance heat transfer rate not only by their high thermal conductivity and also by their mixing effect. When these two subjects come together even more interesting behaviors happen. This paper presents the result of heat transfer enhacment by slurry of metal nanoparticles in porous media in various of flow velocities, heat flux and porous media structures e.g. PPI and particle concentration of nanofluid.

scholarly journals Thermal Conductivity Enhancement Phenomena in Ionic Liquid-Based Nanofluids (Ionanofluids)

2019 ◽  
Vol 72 (2) ◽  
pp. 21 ◽  
Author(s):  
Kamil Oster ◽  
Christopher Hardacre ◽  
Johan Jacquemin ◽  
Ana P. C. Ribeiro ◽  
Abdulaziz Elsinawi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquids ◽  
Theoretical Calculations ◽  
Industrial Applications ◽  
Theoretical Modelling ◽  
Conductivity Enhancement ◽  
Heat Transfer Fluids ◽  
Transfer Unit ◽  
Dispersion Of Nanoparticles

The dispersion of nanoparticles into ionic liquids leads to enhancement of their thermal conductivity. Several papers report on various enhancement values, whereas the comparison between these values with those from theoretical calculations is not always performed. These thermal conductivity enhancements are desired due to their beneficial impact on heat transfer performance in processes requiring the utilisation of heat transfer fluids. Moreover, on the one hand, the theoretical modelling of these enhancements might lead to an easier, cheaper, and faster heat transfer unit design, which could be an enormous advantage in the design of novel industrial applications. On the other hand, it significantly impacts the enhancement mechanism. The aim of this work is to discuss the enhancement of thermal conductivity caused by the dispersion of nanoparticles in ionic liquids, including the analysis of their errors, followed by its theoretical modelling. Furthermore, a comparison between the data reported herein with those available in the literature is carried out following the reproducibility of the thermal conductivity statement. The ionic liquids studied were 1-butyl-3-methylimidazolium dicyanamide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium ethylsulfate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-hexyl-3-methylimidazolium hexafluorophosphate, while carbon nanotubes, boron nitride, and graphite were selected as nanoparticles to be dispersed in the investigated ionic liquids to design novel heat transfer fluids.

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.

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 Transfer Properties of Engine Oils

2005 ◽  
Author(s):  
Scott Wrenick ◽  
Paul Sutor ◽  
Harold Pangilinan ◽  
Ernest E. Schwarz
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Diesel Engine ◽  
Specific Heat ◽  
Mineral Oil ◽  
Engine Oil ◽  
Group V ◽  
Engine Oils ◽  
Heat Transfer Fluids ◽  
Transfer Properties

The thermal properties of engine oil are important traits affecting the ability of the oil to transfer heat from the engine. The larger the thermal conductivity and specific heat, the more efficiently the oil will transfer heat. In this work, we measured the thermal conductivity and specific heat of a conventional mineral oil-based diesel engine lubricant and a Group V-based LHR diesel engine lubricant as a function of temperature. We also measured the specific heat of ethylene glycol. The measured values are compared with manufacturers’ data for typical heat transfer fluids. The Group V-based engine oil had a higher thermal conductivity and slightly lower specific heat than the mineral oil-based engine oil. Both engine oils had values comparable to high-temperature heat transfer fluids.

Analysis of nanofluids as a means of thermal conductivity enhancement in heavy machineries

2014 ◽  
Vol 66 (2) ◽  
pp. 238-243 ◽  
Author(s):  
Ayush Jain ◽  
Imbesat Hassan Rizvi ◽  
Subrata Kumar Ghosh ◽  
P.S. Mukherjee
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ethylene Glycol ◽  
Base Fluid ◽  
High Concentration ◽  
Content Type ◽  
Conductivity Enhancement ◽  
Heavy Machinery ◽  
Heat Transfer Fluids ◽  
Experimental Findings

Purpose – Nanofluids exhibit enhanced heat transfer characteristics and are expected to be the future heat transfer fluids particularly the lubricants and transmission fluids used in heavy machinery. For studying the heat transfer behaviour of the nanofluids, precise values of their thermal conductivity are required. For predicting the correct value of thermal conductivity of a nanofluid, mathematical models are necessary. In this paper, the effective thermal conductivity of various nanofluids has been reported by using both experimental and mathematical modelling. The paper aims to discuss these issues. Design/methodology/approach – Hamilton and Crosser equation was used for predicting the thermal conductivities of nanofluids, and the obtained values were compared with the experimental findings. Nanofluid studied in this paper are Al2O3 in base fluid water, Al2O3 in base fluid ethylene glycol, CuO in base fluid water, CuO in base fluid ethylene glycol, TiO2 in base fluid ethylene glycol. In addition, studies have been made on nanofluids with CuO and Al2O3 in base fluid SAE 30 particularly for heavy machinery applications. Findings – The study shows that increase in thermal conductivity of the nanofluid with particle concentration is in good agreement with that predicted by Hamilton and Crosser at typical lower concentrations. Research limitations/implications – It has been observed that deviation between experimental and theoretical results increases as the volume concentration of nanoparticles increases. Therefore, the mathematical model cannot be used for predicting thermal conductivity at high concentration values. Originality/value – Studies on nanoparticles with a standard mineral oil as base fluid have not been considered extensively as per the previous literatures available.

scholarly journals Phase change dispersion, potentially a new class of heat transfer fluids

2016 ◽  
Vol 745 ◽  
pp. 032133 ◽  
Author(s):  
L J Fischer ◽  
S von Arx ◽  
U Wechsler ◽  
S Züst ◽  
J Worlitschek
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Heat Transfer Fluids ◽  
New Class

scholarly journals Investigation of heat transfer enhancement in an annular conduit with angled fins using functionalized GNP colloidal suspension

2021 ◽  
Vol 945 (1) ◽  
pp. 012058
Author(s):  
Sayshar Ram Nair ◽  
Cheen Sean Oon ◽  
Ming Kwang Tan ◽  
S.N. Kazi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Power Plants ◽  
Colloidal Suspension ◽  
Industrial Applications ◽  
Point Of View ◽  
Solid Particles ◽  
Working Fluid

Abstract Heat exchangers are important equipment with various industrial applications such as power plants, HVAC industry and chemical industries. Various fluids that are used as working fluid in the heat exchangers such as water, oil, and ethylene glycol. Researchers have conducted various studies and investigations to improve the heat exchanger be it from material or heat transfer point of view. There have been attempts to create mixtures with solid particles suspended. This invention had some drawbacks since the pressure drop was compromised, on top of the occurrence of sedimentation or even erosion, which incurs higher maintenance costs. A new class of colloidal suspension fluid that met the demands and characteristics of a heat exchanger was then created. This novel colloidal suspension mixture was then and now addressed as “nanofluid”. In this study, the usage of functionalized graphene nanoplatelet (GNP) nanofluids will be studied for its thermal conductivity within an annular conduit with angled fins, which encourage swirling flows. The simulation results for the chosen GNP nanofluid concentrations have shown an enhancement in thermal conductivity and heat transfer coefficient compared to the corresponding base fluid thermal properties. The data from this research is useful in industrial applications which involve heat exchangers with finned tubes.

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