The effects of temperature and volume fraction on the thermal conductivity of functionalized DWCNTs/ethylene glycol nanofluid

In the present article, the effects of temperature and nanoparticles volume fraction on the viscosity of copper oxide-ethylene glycol nanofluid have been investigated experimentally. The experiments have been conducted in volume fractions of 0 to 1.5 % and temperatures from 27.5 to 50 °C. The shear stress computed by experimental values of viscosity and shear rate for volume fraction of 1% and in different temperatures show that this nanofluid has Newtonian behaviour. The experimental results reveal that in a given volume fraction when temperature increases, viscosity decreases, but relative viscosity varies. Also, in a specific temperature, nanofluid viscosity and relative viscosity increase when volume fraction increases. The maximum amount of increase in relative viscosity is 82.46% that occurs in volume fraction of 1.5% and temperature of 50 °C. Some models of computing nanofluid viscosity have been suggested. The greatest difference between the results obtained from these models and experimental results was down of 4 percent that shows that there is a very good agreement between experimental results and the results obtained from these models.

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Thermal Conductivity Analysis of Ethylene Glycol/H2O- Based MgFe2O4 Ferrofluid

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1048.83 ◽

2022 ◽

Vol 1048 ◽

pp. 83-88

Author(s):

K. Ajith ◽

Archana Sumohan Pillai ◽

I.V. Muthu Vijayan Enoch ◽

A. Brusly Solomon

Keyword(s):

Thermal Conductivity ◽

Magnetic Flux ◽

Surface Morphology ◽

Ethylene Glycol ◽

Structural Characterization ◽

Magnetic Nanoparticle ◽

Volume Fraction ◽

Current Investigation ◽

Step Method ◽

Volume Fractions

The current investigation aims to synthesize MgFe2O4 magnetic nanoparticle and measure the thermal conductivity of MgFe2O4 ferrofluid. Prepared MgFe2O4 nanoparticle's structural characterization, the concentration of constituents, and surface morphology were analyzed using XRD, EDAX, and TEM respectively. This study also analyses the influence of magnetic flux on the thermal conductivity of MgFe2O4/ EG: H2O (60:40) based ferrofluids formed by the two-step method. Thermal conductivity of ferrofluid measured at different volume fractions (ranging from 0.01% to 0.20%) show that thermal conductivity augmented with an escalation in volume fraction and the highest enhancement of 10.32% was reached at 0.20% volume fraction. Results indicate that the applied magnetic flux improves the thermal conductivity of ferrofluid from 10.32% to 14.75% at 0.20% volume fraction and 350 Gauss Magnetic flux.

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A Study on the Effects of Temperature and Volume Fraction on Thermal Conductivity of Copper Oxide Nanofluid

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2007.787 ◽

2007 ◽

Vol 7 (6) ◽

pp. 2161-2166 ◽

Cited By ~ 7

Author(s):

Ching-Song Jwo ◽

Ho Chang ◽

Tun-Ping Teng ◽

Mu-Jnug Kao ◽

Yu-Ting Guo

Keyword(s):

Thermal Conductivity ◽

Copper Oxide ◽

Volume Fraction ◽

Effects Of Temperature

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Empirical correlations to predict thermophysical and heat transfer characteristics of nanofluids

Thermal Science ◽

10.2298/tsci0802027v ◽

2008 ◽

Vol 12 (2) ◽

pp. 27-37 ◽

Cited By ~ 42

Author(s):

Vasu Velagapudi ◽

Krishna Konijeti ◽

Kumar Aduru

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Ethylene Glycol ◽

Volume Fraction ◽

Solid Particles ◽

Engine Oil ◽

Fluid Temperature ◽

Flow Conditions ◽

Thermophysical Characteristics ◽

Laminar And Turbulent Flow

Nanofluids exhibits larger thermal conductivity due to the presence of suspended nanosized solid particles in them such as Al2O3, Cu, CuO,TiO2, etc. Varieties of models have been proposed by several authors to explain the heat transfer enhancement of fluids such as water, ethylene glycol, engine oil containing these particles. This paper presents a systematic literature survey to exploit the thermophysical characteristics of nanofluids. Based on the experimental data available in the literature empirical correlation to predict the thermal conductivity of Al2O3, Cu, CuO, and TiO2 nanoparticles with water and ethylene glycol as base fluid is developed and presented. Similarly the correlations to predict the Nusselt number under laminar and turbulent flow conditions is also developed and presented. These correlations are useful to predict the heat transfer ability of nanofluids and takes care of variations in volume fraction, nanoparticle size and fluid temperature. The improved thermophysical characteristics of a nanofluid make it excellently suitable for future heat exchange applications. .

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The Thermal Transport Properties of Ethylene Glycol Based MGO Nanofluids

ASME 2009 7th International Conference on Nanochannels, Microchannels and Minichannels ◽

10.1115/icnmm2009-82032 ◽

2009 ◽

Cited By ~ 1

Author(s):

Wei Yu ◽

Hua-Qing Xie ◽

Yang Li ◽

Li-Fei Chen

Keyword(s):

Thermal Conductivity ◽

Ethylene Glycol ◽

Transport Properties ◽

Volume Fraction ◽

Metallic Oxide ◽

Mgo Nanoparticles ◽

Conductivity Enhancement ◽

Classical Models ◽

Constant Viscosity ◽

Solid Liquid

Ethylene glycol based nanofluids containing MgO nanoparticles (MgO-EG) were prepared, and the transport properties including thermal conductivity and viscosity were measured. The results show that the thermal conductivity of MgO-EG nanofluid depends strongly on particle concentration, and it increases nonlinearly with the volume fraction of nanoparticles. The thermal conductivity of MgO-EG nanofluids is larger than that of nanofluids containing the same volume fraction of TiO2, ZnO, Al2O3 and SiO2, maybe due to its lowest viscosity among the tested metallic oxide nanofluids. Thermal conductivity enhancement of MgO-EG nanofluids appears weak dependence on temperature from 10 to 60°C, and the enhanced ratios are almost constant. Viscosity measurements show that MgO-EG nanofluids demonstrate Newtonian behavior, and the viscosity significantly decreases with temperature. The thermal conductivity and viscosity increments of nanofluids are higher than those of the existing classical models for the solid-liquid mixture.

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Effect of Volume Fraction and Temperature on Thermal Conductivity of SiO2 Nanofluids

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.1178 ◽

2011 ◽

Vol 306-307 ◽

pp. 1178-1181 ◽

Cited By ~ 1

Author(s):

Bao Jie Zhu ◽

Wei Lin Zhao ◽

Dong Dong Li ◽

Jin Kai Li

Keyword(s):

Thermal Conductivity ◽

Ethylene Glycol ◽

Volume Fraction ◽

Experimental Results ◽

Transient Hot Wire ◽

Hot Wire ◽

Transient Hot Wire Method ◽

Wire Method ◽

Thermal Conductivities

Thermal conductivities of two kinds of nanofluids (SiO2-water and SiO2-ethylene glycol) were measured by transient hot-wire method at different volume fraction and temperature. Influences of volume fraction of particles and temperature on thermal conductivities of nanofluids were analyzed. The Experimental results show that thermal conductivities of nanofluids are higher than those of base fluids, and increase with the increase of volume fraction and temperature. When approximately 0.5% volume fraction of SiO2nanoparticles are added into water and ethylene glycol at the temperature 50°C, the thermal conductivities are enhanced 46.2% and 62.8% respectively.

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Nanofluids as a Coolant in Functional Units’ Coolers of Automotive Equipment

Elektrotekhnologii i elektrooborudovanie v APK ◽

10.22314/2658-4859-2021-68-3-137-141 ◽

2021 ◽

Vol 3 (44) ◽

pp. 137-141

Author(s):

Ekaterina P. Parlyuk ◽

Keyword(s):

Thermal Conductivity ◽

Ethylene Glycol ◽

Copper Nanoparticles ◽

Volume Fraction ◽

Research Purpose ◽

Heat Conducting ◽

Main Function ◽

Metal Consumption ◽

Heat Carriers ◽

Base Liquid

One of the most important elements of the cooling system of any automotive internal combustion engine is a coolant. Most often, water and a mixture of water with antifreeze are used as a coolant. Its main function is to transfer heat or to cool the engine. Nanofluids are promising heat carriers, with the help of which it is possible to reduce the metal consumption of aggregates, increase safety in emergency transient modes accompanied by boiling. (Research purpose) The research purpose is studying the possibilities, features and prospects of using innovative heat carriers as coolants of automotive equipment, which will allow overcoming the ineﬃciency of water and ethylene glycol mixtures, which consists in low thermal conductivity. (Materials and methods) Nanofluids consisting of a base liquid and nanoparticles of a highly heat-conducting material were proposed as innovative heat carriers. Their use in transport power plant coolers will reduce their volume and weight. Mixing of ethylene glycol and copper nanoparticles is eﬀective, in such cases it is important to investigate the eﬀect of the volume fraction of copper nanoparticles and the base liquid on thermal characteristics or to reduce the size of the radiator. Copper nanoparticles have better thermal conductivity than other nanoparticles (for example, aluminum oxide). (Results and discussion) It has been proved that the use of nanofluids in heating and ventilation systems can give a significant increase in heat transfer. At present the science of nanofluids is in its initial stage, for the development of this direction it is necessary to conduct comprehensive experimental studies of their chemical and physical properties, theoretical analysis, and compilation of general calculated correlations. (Conclusions) It was revealed that nanofluids can be eﬀectively used as heat carriers of transport engines, with their use the metal consumption of coolers is reduced, the safety of units in emergency modes, including those accompanied by boiling, is increased.

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A Study of Some Mechanical and Physical Properties for Palm Fiber/Polyester Composite

Engineering and Technology Journal ◽

10.30684/etj.v38i3b.598 ◽

2020 ◽

Vol 38 (3B) ◽

pp. 104-114

Author(s):

Samah M. Hussein

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Dielectric Constant ◽

Date Palm ◽

Volume Fraction ◽

Unsaturated Polyester ◽

Dielectric Strength ◽

Palm Fiber ◽

Mechanical And Physical Properties ◽

Polyester Composite

This research has been done by reinforcing the matrix (unsaturated polyester) resin with natural material (date palm fiber (DPF)). The fibers were exposure to alkali treatment before reinforcement. The samples have been prepared by using hand lay-up technique with fiber volume fraction of (10%, 20% and 30%). After preparation of the mechanical and physical properties have been studied such as, compression, flexural, impact strength, thermal conductivity, Dielectric constant and dielectric strength. The polyester composite reinforced with date palm fiber at volume fraction (10% and 20%) has good mechanical properties rather than pure unsaturated polyester material, while the composite reinforced with 30% Vf present poor mechanical properties. Thermal conductivity results indicated insulator composite behavior. The effect of present fiber polar group induces of decreasing in dielectric strength, and increasing dielectric constant. The reinforcement composite 20% Vf showed the best results in mechanical, thermal and electrical properties.

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