Convective heat transfer characteristics of nanofluids under laminar and turbulent flow conditions

Kim, Doo-Hyun; Kwon, Yong Hoon; Cho, Yonghyeon; Li, Chengguo; Cheong, Seongir; Hwang, Yujin; Lee, Jae-Keun; Hong, Daeseung; Moon, Sung-Won

doi:10.1016/j.cap.2008.12.047

Cited by 480 publications

(155 citation statements)

References 12 publications

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“…When comparing the data with each other at the same fluid velocity, the nanofluids showed a decrease in heat transfer coefficient when compared with water. This was due to the fact that MWCNT-water nanofluids have a larger viscosity than water and the data shifted to lower Reynolds numbers, therefore it was considered to compare the data with correlations Figure 10 Tables Table 1: Comparison of previous work in terms of flow range, type of nanofluid and enhancement [9] Laminar Graphite-water 22% enhancement at 50°C 15% enhancement at 70°C Ding et al [3] Laminar MWCNT-water 350% enhancement at the entrance region Murshed et al [11] Laminar TiO 2 -water 12% and 14% enhancement at the entrance region Garg et al [12] Laminar MWCNT-water 32% enhancement Kim et al [13] Laminar and turbulent …”

Section: Resultsmentioning

confidence: 99%

“…The pressure loss equation is used to calculate the friction factor: ( 13 ) which was then simplified to:…”

Section: Data Reductionmentioning

confidence: 99%

“…A possible reason for the increase in heat transfer is that the nanoparticles presented in the base liquid increase the thermal conductivity, delay and disturb the thermal boundary layer and accelerate the energy exchange process in the fluid due to the chaotic movement of the nanoparticles [13,17,39]. The increase in the thermal conductivity leads to an increase in heat transfer performance whereas the increase in viscosity leads to an increase in boundary layer thickness, which results in a decrease in heat transfer performance [40].…”

Section: Convective Heat Transfer Of Mwcnt-water Nanofluidsmentioning

confidence: 99%

“…At a volume concentration of 18.9%, the heat transfer enhancement was approximately 50% for a Reynolds number greater than 1 000. Evaluating the literature shows that there are few works [6,7,8,9,10,11,13,14,17,18] that have reported on convective heat transfer characteristics of nanofluids, especially CNT nanofluids [3,12,15,16]. All of the studies considered in literature either test in the laminar [3,7,8,9,10,11,12,13,14,15] or high turbulent flow range [6,7,13,15,16,17] and very few tested in the transitional flow range [19].…”

Section: Introductionmentioning

confidence: 99%

“…Kim et al [13] used two different nanofluids in their experiments. They tested in the laminar and turbulent flow range.…”

Section: Introductionmentioning

confidence: 99%

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The influence of multi-walled carbon nanotubes on single-phase heat transfer and pressure drop characteristics in the transitional flow regime of smooth tubes

Meyer

McKrell

Grote

2013

International Journal of Heat and Mass Transfer

115

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In this paper, the convective heat transfer enhancement of aqueous suspensions of multiwalled carbon nanotubes flowing through a straight horizontal tube was investigated experimentally for a Reynolds number range of 1 000 -8 000, which included the transitional flow regime. The tube was made out of copper with an internal diameter of 5.16 mm.Experiments were conducted at a constant heat flux of 13 kW/m 2 with 0.33%, 0.75% and 1.0% volume concentrations of multi-walled carbon nanotubes. The nanotubes had an outside diameter of 10 -20 nm, an inside diameter of 3 -5 nm and a length of 10 -30 µm.Temperature and pressure drop measurements were taken, from which the heat transfer coefficients and friction factors were determined as a function of Reynolds number. It was found that heat transfer was enhanced when comparing the data on a Reynolds-Nusselt graph but when comparing the data at the same velocity, it was shown that heat transfer was not enhanced. Performance evaluation of the nanofluids showed that the increase in viscosity was four times the increase in the thermal conductivity, which resulted in an inefficient nanofluid.

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Section: Resultsmentioning

confidence: 99%

“…The pressure loss equation is used to calculate the friction factor: ( 13 ) which was then simplified to:…”

Section: Data Reductionmentioning

confidence: 99%

Section: Convective Heat Transfer Of Mwcnt-water Nanofluidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Kim et al [13] used two different nanofluids in their experiments. They tested in the laminar and turbulent flow range.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The influence of multi-walled carbon nanotubes on single-phase heat transfer and pressure drop characteristics in the transitional flow regime of smooth tubes

Meyer

McKrell

Grote

2013

International Journal of Heat and Mass Transfer

115

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Theoretical analysis of heat transfer and friction factor for turbulent flow of nanofluids through pipes

et al. 2016

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A numerical model for determining the turbulent characteristics of fluid flow and heat transfer is presented, treating certain constants in the van Driest eddy diffusivity equation of momentum and heat as variables. The viscosity and thermal conductivity of nanofluids are estimated using regression equations. It was observed that the turbulent characteristics of nanofluids are different from those of water. The numerical results indicate a higher velocity of SiO 2 nanofluid and lower eddy diffusivity compared to Cu under similar operating conditions. The nanofluid temperature gradient increases with concentration and decreases with temperature. However, the temperature gradient is significantly influenced by the particle density. Equations for estimating the coefficient and the Prandtl index in the eddy diffusivity equations of momentum and heat, respectively, are developed as a function of Reynolds number, concentration, and nanofluid properties. The Prandtl index value decreases with increasing concentration, reflecting the reduction in heat transfer coefficients observed at lower operating temperatures.

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Numerical study of ferrofluid flow and heat transfer in the presence of a non‐uniform magnetic field in rectangular microchannels

Mohammadpourfard

2012

Heat Trans. Asian Res.

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This paper presents a numerical investigation of the hydro‐thermal behavior of a ferrofluid in rectangular minichannels in the presence of a non‐uniform magnetic field using a two‐phase mixture model and control volume technique. Effects of increasing the diameter of nanoparticles, and channel aspect ratio have also been studied. It is concluded that the magnetic field with a negative gradient increases the Nusselt number and the rate of this increment depends on the channel aspect ratio. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21004

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Convective heat transfer characteristics of nanofluids under laminar and turbulent flow conditions

Cited by 480 publications

References 12 publications

The influence of multi-walled carbon nanotubes on single-phase heat transfer and pressure drop characteristics in the transitional flow regime of smooth tubes

The influence of multi-walled carbon nanotubes on single-phase heat transfer and pressure drop characteristics in the transitional flow regime of smooth tubes

Theoretical analysis of heat transfer and friction factor for turbulent flow of nanofluids through pipes

Numerical study of ferrofluid flow and heat transfer in the presence of a non‐uniform magnetic field in rectangular microchannels

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