A Comparison of Empirical Correlations of Viscosity and Thermal Conductivity of Water-Ethylene Glycol-Al2O3 Nanofluids

Because of their superb thermal conductivity, nanofluids are seen as new generation of cooling mediums in many engineering applications. It is well established that even a small amount of nanoparticles mixed with a base fluid may result in distinct thermal conductivity enhancement. On the other hand, addition of nanoparticles to the base fluid results in its substantial viscosity increase. Therefore, it is very difficult to evaluate the relative importance of viscosity and thermal conductivity of the nanofluid on convective heat transfer performance. In order to estimate such resultant impact properly, it is necessary to develop reliable correlation equations for predictions of these two thermophysical properties of nanofluids. In this paper, the thermal conductivity and dynamic viscosity of five fluids, i.e., pure water, ethylene glycol (EG) and three mixtures of water and EG with volume ratio of 40:60, 50:50 and 60:40 have been experimentally determined. The aforementioned fluids served as base fluids in nanofluids with Al2O3 nanoparticles at the concentration of 0.01%, 0.1% and 1% by weight. A set of 20 correlations for prediction of thermal conductivity and dynamic viscosity of base fluids and corresponding nanofluids has been developed. Moreover, present results have been confronted with literature data and predictions made by use of carefully selected recognized literature correlations.

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

Industrial Lubrication and Tribology ◽

10.1108/ilt-03-2012-0024 ◽

2014 ◽

Vol 66 (2) ◽

pp. 238-243 ◽

Cited By ~ 2

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.

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Thermal conductivity enhancement in gold decorated graphene nanosheets in ethylene glycol based nanofluid

Scientific Reports ◽

10.1038/s41598-020-71740-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

M. C. Mbambo ◽

M. J. Madito ◽

T. Khamliche ◽

C. B. Mtshali ◽

Z. M. Khumalo ◽

...

Keyword(s):

Thermal Conductivity ◽

Ethylene Glycol ◽

Base Fluid ◽

Graphene Nanosheets ◽

Synthesis Method ◽

Particle Diameter ◽

Laser Wavelength ◽

Hybrid Nanofluid ◽

Average Particle ◽

Conductivity Enhancement

Abstract We report on the synthesis and thermal conductivity of gold nanoparticles (AuNPs) decorated graphene nanosheets (GNs) based nanofluids. The GNs-AuNPs nanocomposites were synthesised using a nanosecond pulsed Nd:YAG laser (wavelength = 1,064 nm) to ablate graphite target followed by Au in ethylene glycol (EG) base fluid to obtain GNs-AuNPs/EG hybrid nanofluid. The characterization of the as-synthesised GNs-AuNPs/EG hybrid nanofluid confirmed a sheet-like structure of GNs decorated with crystalline AuNPs with an average particle diameter of 6.3 nm. Moreover, the AuNPs appear smaller in the presence of GNs which shows the advantage of ablating AuNPs in GNs/EG. The thermal conductivity analysis in the temperature range 25–45 °C showed that GNs-AuNPs/EG hybrid nanofluid exhibits an enhanced thermal conductivity of 0.41 W/mK compared to GNs/EG (0.35 W/mK) and AuNPs/EG (0.39 W/mK) nanofluids, and EG base fluid (0.33 W/mK). GNs-AuNPs/EG hybrid nanofluid displays superior enhancement in thermal conductivity of up to 26% and this is due to the synergistic effect between AuNPs and graphene sheets which have inherent high thermal conductivities. GNs-AgNPs/EG hybrid nanofluid has the potential to impact on enhanced heat transfer technological applications. Also, this work presents a green synthesis method to produce graphene-metal nanocomposites for various applications.

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Ultrasonic and thermophysical studies of ethylene glycol nanofluids containing TiO2 nanoparticles and their heat transfer enhancements

Johnson Matthey Technology Review ◽

10.1595/205651320x15940360546454 ◽

2020 ◽

Author(s):

Mohit Gupta ◽

Devraj Singh ◽

Shakti Pratap Singh ◽

Ashish Mathur ◽

Shikha Wadhwa ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Ethylene Glycol ◽

Tio2 Nanoparticles ◽

Ultrasonic Velocity ◽

Base Fluid ◽

Sol Gel ◽

Interaction Force ◽

Thermal Conductivity Enhancement ◽

Conductivity Enhancement

In present investigation, TiO2 nanostructures were synthesized via simple sol-gel technique and characterized with XRD, SEM-EDX, HRTEM and UV-visible spectroscopy techniques. The temperature and concentration dependence of thermal conductivity enhancement and ultrasonic velocity have been explored in ethylene glycol (EG)-based TiO2 nanofluids. The obtained results showed 24% enhancement in thermal conductivity at higher temperature (80°C) of base fluid ethylene glycol by adding 1.0 wt.% of TiO2 nanoparticles. The behaviour of thermal conductivity enhancement and ultrasonic velocity with temperature in prepared nanofluids has been explained with help of existing phenomena. The increase the ultrasonic velocity in ethylene glycol with TiO2 nanoparticles shows that strong cohesive interaction force rises among the nanoparticles and base fluid. These results divulge that TiO2 nanoparticles can be considered for the applications of next-generation competent heat transfer in nanofluids.

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Experimental Investigation of Thermo-Physical Properties of Tri-Hybrid Nanoparticles in Water-Ethylene Glycol Mixture

Walailak Journal of Science and Technology (WJST) ◽

10.48048/wjst.2021.9335 ◽

2021 ◽

Vol 18 (8) ◽

Author(s):

Anwar Ilmar RAMADHAN ◽

Wan Hamzah AZMI ◽

Rizalman MAMAT

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Ethylene Glycol ◽

Physical Properties ◽

Dynamic Viscosity ◽

Volume Concentration ◽

Hybrid Nanoparticles ◽

Maximum Enhancement ◽

Hybrid Nanofluids ◽

Thermo Physical Properties

In recent years, research has focused on enhancing the thermo-physical properties of a single component nanofluid. Therefore, hybrid or composite nanofluids have been developed to improve heat transfer performance. The thermo-physical properties of the Al2O3-TiO2-SiO2 nanoparticles suspended in a base of water (W) and ethylene glycol (EG) at constant volume ratio of 60:40 and different volume concentrations were investigated. The experiment was conducted for the volume concentrations of 0.05, 0.1, 0.2, and 0.3% of Al2O3-TiO2-SiO2 nanofluids at different temperatures of 30, 40, 50, 60, and 70 °C. Thermal conductivity and dynamic viscosity measurements were carried out at temperatures ranging from 30 to 70 °C by using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV III Ultra Rheometer, respectively. The highest thermal conductivity for tri-hybrid nanofluids was obtained at 0.3% volume concentration, and the maximum enhancement was increased up to 9% higher than the base fluid (EG/W). Tri-hybrid nanofluids with a volume concentration of 0.05% gave the lowest effective thermal conductivity of 4.8 % at 70 °C temperature. Meanwhile, the dynamic viscosity of the tri-hybrid nanofluids was influenced by volume concentration and temperature. Furthermore, tri-hybrid nanofluids behaved as a Newtonian fluid for volume concentrations from 0.05 to 3.0%. The properties enhancement ratio (PER) estimated that the tri-hybrid nanofluids will aid in heat transfer for all samples in the present. The new correlations for thermal conductivity and dynamic viscosity of tri-hybrid nanofluids were developed with minimum deviation. As a conclusion, the combination of the enhancement in thermal conductivity and dynamic viscosity for tri-hybrid at 0.3% volume concentration was found the optimum condition with more advantage for heat transfer than other concentrations.

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Study the Effect of Gum Arabic and Triton X-100 on Stability and Thermal Conductivity of ZnO/ethylene glycol Nanofluids

Revista de Chimie ◽

10.37358/rc.21.1.8400 ◽

2021 ◽

Vol 72 (1) ◽

pp. 18-24

Author(s):

Noor Sabeeh Majeed ◽

Hussein A. Alabdly ◽

Hussam Nadum Abdalraheem Al Ani ◽

Dumitru Pascu ◽

Aurelia Cristina Nechifor

Keyword(s):

Thermal Conductivity ◽

Zinc Oxide ◽

Zeta Potential ◽

Ethylene Glycol ◽

Base Fluid ◽

Thermal Conductivity Coefficient ◽

Uv Spectroscopy ◽

Gum Arabic ◽

The Stability ◽

Triton X

Stability of nanofluids is one of the most important factors to ensure the most benefit of the properties of nanoparticles. Zinc oxide was used in the research with concentration between (0.2-1) wt. % with ethylene glycol base fluid. The stability of ZnO nanofluid was enhanced by adding two types of surfactants Tx-100 and Gum Arabic with concentration of (0.1-0.5) vol. % to stabilize the ZnO nanoparticles in the base fluid. The results showed that the Gum Arabic surfactant led to more stable fluid than that of Tx-100; this was shown from zeta potential and UV spectroscopy measurements. The thermal conductivity coefficient was also measured, and the results showed that the thermal conductivity increased with adding surfactant than without using a stabilizer.

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Optimization, modeling and accurate prediction of thermal conductivity and dynamic viscosity of stabilized ethylene glycol and water mixture Al 2 O 3 nanofluids by NSGA-II using ANN

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2016.08.015 ◽

2017 ◽

Vol 82 ◽

pp. 154-160 ◽

Cited By ~ 86

Author(s):

Mohammad Hemmat Esfe ◽

Peyman Razi ◽

Mohammad Hadi Hajmohammad ◽

Seyed Hadi Rostamian ◽

Wail Sami Sarsam ◽

...

Keyword(s):

Thermal Conductivity ◽

Ethylene Glycol ◽

Dynamic Viscosity ◽

Accurate Prediction ◽

Water Mixture ◽

Nsga Ii ◽

Optimization Modeling

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An experimental study on the thermal conductivity and dynamic viscosity of TiO 2 -SiO 2 nanofluids in water: Ethylene glycol mixture

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2017.05.024 ◽

2017 ◽

Vol 86 ◽

pp. 181-189 ◽

Cited By ~ 75

Author(s):

M.F. Nabil ◽

W.H. Azmi ◽

K. Abdul Hamid ◽

Rizalman Mamat ◽

Ftwi Y. Hagos

Keyword(s):

Thermal Conductivity ◽

Experimental Study ◽

Ethylene Glycol ◽

Dynamic Viscosity

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Change of Thermal Conductivity and Cooling Performance for Water Based Al2O3-Surfactant Nanofluid with Time Lapse

International Journal of Air-Conditioning and Refrigeration ◽

10.1142/s2010132518500098 ◽

2018 ◽

Vol 26 (01) ◽

pp. 1850009 ◽

Cited By ~ 3

Author(s):

Man Bae Kim ◽

Hong Gen Park ◽

Chang Yong Park

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Cooling System ◽

Pure Water ◽

Sodium Dodecyl ◽

Convection Heat Transfer ◽

Sodium Dodecyl Benzene Sulfonate ◽

Time Lapse ◽

Convection Heat ◽

Conductivity Enhancement

An experimental research was performed to study the effect of time lapse on the change of water-Al2O3 nanofluid thermal conductivity and its convection heat transfer. The size of Al2O3 nanoparticle size was 20[Formula: see text]nm and 70[Formula: see text]nm, and initial volumetric concentration range was from 0.5% to 3%. A surfactant was added to the nanofluid and the change of thermal conductivity and convection heat transfer was also measured. The surfactant was Sodium Dodecyl Benzene Sulfonate (SDBS) and its mass fractions in the nanofluid were from 0.5% to 3.0%. Thermal conductivity of water and nanofluid was measured by the transient hot wire method. The accuracy of the measurement method was confirmed by the measurement error with 0.92% for distilled water at 20[Formula: see text]C. The thermal conductivity of the nanofluid without SDBS increased up to 11.3% and the enhancement decreased with time lapse. The reduction of thermal conductivity enhancement with the time lapse could be retarded by the addition of SDBS and its effect became higher with the increase of its mass fraction. The convection heat transfer characteristics of the nanofluid was measured in a small cooling system. Compared with pure water, nanofluid convection heat transfer could be enhanced but higher pressure drop also occurred. Compared with the convection heat transfer enhancement for the nanofluid without SDBS, the addition of SDBS decreased the enhancement at the initial stage of the experiment, but it could retard the reduction of convection heat transfer with time lapse.

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Thermal Transport Properties of Nanofluids Containing Carbon Nanotubes

ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2008-62210 ◽

2008 ◽

Cited By ~ 1

Author(s):

Huaqing Xie ◽

Lifei Chen ◽

Yang Li ◽

Wei Yu

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Base Fluid ◽

Volume Fraction ◽

Thermal Conductivity Enhancement ◽

Mechanochemical Reaction ◽

Multiwalled Carbon ◽

Conductivity Enhancement ◽

Lower Viscosity ◽

Potential Applications

Multiwalled carbon nanotubes (CNTs) have been treated by using a mechanochemical reaction method to enhance their dispersibility for producing CNT nanofluids. The thermal conductivity was measured by a short hot wire technique and the viscosity was measured by a rotary viscometer. The thermal conductivity enhancement reaches up to 17.5% at a volume fraction of 0.01 for an ethylene glycol based nanofluid. Temperature variation was shown to have no obvious effects on the thermal conductivity enhancement for the as prepared nanofluids. With an increase in the thermal conductivity of the base fluid, the thermal conductivity enhancement of a nanofluid decreases. At low volume fractions (<0.4 Vol%), nanofluids have lower viscosity than the corresponding base fluid due to lubricative effect of nanoparticles. When the volume fraction is higher than 0.4 Vol%, the viscosity increases with nanoparticle loadings. The prepared nanofluids, with no contamination to medium, good fluidity, stability, and high thermal conductivity, would have potential applications as coolants in advanced thermal systems.

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