Avaliação experimental do desempenho termo-hidráulico de nanofluidos de nanotubos de carbono de parede simples em escoamento monofásico em regime turbulento

Gómez, Abdul Orlando Cárdenas

doi:10.14393/ufu.di.2015.175

Cited by 2 publications

(1 citation statement)

References 45 publications

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“…Consequently, specific heat of the mixture will decrease with increasing volumetric concentration of nanoparticles, as reported by Murshed [35]. Similar behaviors, for other fluids like mineral oil, water/ethylene glycol mixture, and nanoparticles made of carbon nanotubes and grapheme were obtained by Gómez [36], Flores [33], Oliveira (2018) [31] and Gómez [37].…”

Section: Specific Heat Resultssupporting

confidence: 73%

Experimental Evaluation of Thermal Conductivity and Other Thermophysical Properties of Nanofluids Based on Functionalized (-OH) Mwcnt Nanoparticles Dispersed in Distilled Water

Oliveira¹,

Mesquita²,

Marques³

et al. 2023

ANP

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A possible way to increase thermal conductivity of working fluids, while keeping pressure drop at acceptable levels, is through nanofluids. Nanofluids are nano-sized particles dispersed in conventional working fluids. A great number of materials have potential to be used in nanoparticles production and then in nanofluids; one of them is Multi-Walled Carbon Nano Tubes (MWCNT). They have thermal conductivity around 3000 W/mK while other materials used as nanoparticles like CuO have thermal conductivity of 76.5 W/mK. Due to this fact, MWCNT nanoparticles have potential to be used in nanofluids production, aiming to increase heat transfer rate in energy systems. In this context, the main goal of this paper is to evaluate from the synthesis to the experimental measurement of thermal conductivity of nanofluid samples based on functionalized (−OH) MWCNT nanoparticles. They will be analyzed nanoparticles with different functionalization degrees (4% wt, 6% wt, and 9% wt). In addition, it will be quantified other thermophysical properties (dynamic viscosity, specific heat and specific mass) of the synthetized nanofluids. So, the present work can contribute with experimental data that will help researches in the study and development of MWCNT nanofluids. According to the results, the maximum increment obtained in thermal conductivity was 10.65% in relation to the base fluid (water).

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Section: Specific Heat Resultssupporting

confidence: 73%

Experimental Evaluation of Thermal Conductivity and Other Thermophysical Properties of Nanofluids Based on Functionalized (-OH) Mwcnt Nanoparticles Dispersed in Distilled Water

Oliveira¹,

Mesquita²,

Marques³

et al. 2023

ANP

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Cold start analysis of an engine coolant-MWCNT nanofluid: Synthesis and viscosity behavior under shear stress

Sica

Contreras

Filho

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part D:

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During cold start of internal combustion engines, coolant temperature, and thermal conductivity are key parameters in the heat transfer processes that ultimately affect pollutant emissions and engine performance. Hereupon the use of coolants with suspended nanoparticles, to enhance thermal conductivity, emerged as a promising technology. However, for Newtonian materials, viscosity also increases with nanoparticle concentration. To overcome increased pumping power, the use of non-Newtonian nanofluids makes such application potentially feasible, specifically for shear-thinning materials, in which a higher shear rate leads to reducing shear viscosity due to higher shear stress. Accordingly, a nanofluid, suitable for engine cooling (0.2 wt.% MWCNT-engine coolant/distilled water 30/70 v/v%), was here fabricated and mapped. Shear rate and temperature were varied, with focus on cold start investigation. Shear thinning and shear thickening regions were mapped according to the shear rate levels, for each temperature considered. The nanofluid behaved as shear-thinning material for the entire range of temperatures (−10°C–25°C). Above shear rates of 500 s−1 and flow curves with temperatures below −5°C, a prominent shear thickening behavior was observed. Additionally, the relative apparent viscosity data were compared with four classical models. Regarding the curve fitting parameters of a modified Herschel-Bulkley equation, above 0°C, the apparent yield stress, [Formula: see text], was invariant with temperature. Besides, for the temperature range from 0°C to 20°C, the flow index remained approximately constant. For temperatures above −5°C, infinite-shear-rate viscosity and consistency index presented a linear decrease and a third-degree polynomial-like behavior, respectively.

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Avaliação experimental do desempenho termo-hidráulico de nanofluidos de nanotubos de carbono de parede simples em escoamento monofásico em regime turbulento

Cited by 2 publications

References 45 publications

Experimental Evaluation of Thermal Conductivity and Other Thermophysical Properties of Nanofluids Based on Functionalized (-OH) Mwcnt Nanoparticles Dispersed in Distilled Water

Experimental Evaluation of Thermal Conductivity and Other Thermophysical Properties of Nanofluids Based on Functionalized (-OH) Mwcnt Nanoparticles Dispersed in Distilled Water

Cold start analysis of an engine coolant-MWCNT nanofluid: Synthesis and viscosity behavior under shear stress

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