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that have a small diameter measured in nanoscale in various base fluids took high interest as an enhancement technique called nanofluid [ 6 ]-[ 8 ]. The effect of using this technique was examined experimentally and numerically using various

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Abstract  

This article presents a model, based on dimensionless groups, to predict the viscosity of nanoparticle suspensions, nanofluids. This empirical model expresses the viscosity of a nanofluid as a function of the following: viscosity of the base liquid, particle volume fraction, particle size, properties of the surfactant layer, and temperature. According to this model, viscosity changes nonlinearly with nanoparticle loading. Compared to other models, the new model is in good agreement with experimentally determined viscosity data for alumina–water nanofluids.

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R. A. , Abdulhussein A. A. Heat transfer enhancement using nanofluids: A review of the recent literature , American J. of Nano Research and Applications , Vol. 4 , No. 1 , 2016 , pp. 1 ‒ 5 . [4

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ways that have taken a broad interest in recent years is the use of nanofluid that is clearly shown by an increase in the number of articles in this field [ 6 ]. This method is based on improving the thermal properties of the base fluid by adding small

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requirements by removing high heat dissipation in a relatively small temperature difference. Nanofluids are a new class of thermal fluids that made from dispersing solid nanoscale materials with a range of 1-100 nm and those solids materials have thermal

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Abstract  

Thermal conductivity is an important parameter in the field of nanofluid heat transfer. This article presents a novel model for the prediction of the effective thermal conductivity of nanofluids based on dimensionless groups. The model expresses the thermal conductivity of a nanofluid as a function of the thermal conductivity of the solid and liquid, their volume fractions, particle size and interfacial shell properties. According to this model, thermal conductivity changes nonlinearly with nanoparticle loading. The results are in good agreement with the experimental data of alumina-water and alumina-ethylene glycol based nanofluids.

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Abstract  

Changes in the thermal conductivities of paraffin and mono ethylene glycol (MEG) as a function of β-SiC nanoparticle concentration and size was studied. An enhancement in the effective thermal conductivity was found for both fluids (i.e., both paraffin and MEG) upon the addition of nanoparticles. Although an enhancement in thermal conductivity was found, the degree of enhancement depended on the nanoparticle concentration in a complex way. An increase in particle-to-particle interactions is thought to be the cause of the enhancement. However, the enhancement became muted at higher particle concentrations compared to lower ones. This phenomenon can be related to nanoparticles interactions. An improvement in the thermal conductivities for both fluids was also found as the nanoparticle size shrank. It is believed that the larger Brownian motion for smaller particles causes more particle-to-particle interactions, which, in turn, improves the thermal conductivity. The role that the base-fluid plays in the enhancement is complex. Lower fluid viscosities are believed to contribute to greater enhancement, but a second effect, the interaction of the fluid with the nanoparticle surface, can be even more important. Nanoparticle-liquid suspensions generate a shell of organized liquid molecules on the particle surface. These organized molecules more efficiently transmit energy, via phonons, to the bulk of the fluid. The efficient energy transmission results in enhanced thermal conductivity. The experimentally measured thermal conductivities of the suspensions were compared to a variety of models. None of the models proved to adequately predict the thermal conductivities of the nanoparticle suspensions.

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focused on the enhancement heat transfer using different passive techniques, especially nanofluid methods. Khanafer and Vafai [ 15 ] presented the effects of inserting nanofluid as a thermal heating fluid in different applications and discussed recent

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Journal of Thermal Analysis and Calorimetry
Authors: Benigno Barbés, Ricardo Páramo, Francisco Sobrón, Eduardo Blanco, and Carlos Casanova

thermal conductivity of heat transfer fluids by dispersing and stably suspending nanometer-sized particles. The study of these thermal fluids, the so-called nanofluids, has emerged as a new field of scientific research with innovative applications. One of

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Journal of Flow Chemistry
Authors: Christine Lafforgue-Baldas, Pascale Magaud, Philippe Schmitz, Zhang Zhihao, Sandrine Geoffroy, and Micheline Abbas

I. Papautsky 2009 Microfluid Nanofluid 7 217 – 226 . 9. D. Di Carlo

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