Influence of particle size and shape on turbulent heat transfer characteristics and pressure losses in water-based nanofluids

Meriläinen, Arttu; Seppälä, Ari; Saari, Kari; Seitsonen, Jani; Ruokolainen, Janne; Puisto, S. R.; Rostedt, Niko K. J.; Ala-Nissilä, Tapio

doi:10.1016/j.ijheatmasstransfer.2013.02.032

Cited by 75 publications

(43 citation statements)

References 20 publications

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“…The PCM nanofluids reach higher Nu than water with an equal Re in both laminar and turbulent regimes, and the deviation increases with increasing concentration. Similar behavior has also been widely reported in literature for nanofluids, nanoemulsions and PCM fluids [5][6][7][8]12,19,[21][22][23][24]34]. However, this presentation method has been criticized in several recent publications, since it does not take the pumping power into account [21][22][23][24][25][26].…”

Section: Convective Heat Transfersupporting

confidence: 70%

“…Therefore, the fluids studied herein do not exhibit penalties in pressure losses, which is advantageous in terms of performance in practical applications. Previously, pressure loss penalties of various magnitudes have been reported for both nanofluids and PCM fluids [3,5,12,21,22,29]. In addition, even decreased pressure losses have been reported for PCM fluids in some cases, but that phenomenon can be mostly attributed to turbulence suppression i.e.…”

Section: Friction Factors and Pressure Lossesmentioning

confidence: 98%

“…However, the convection performance of such fluids containing nano-sized PCM particles has not been experimentally evaluated so far. The nanoscale might provide notable benefits over microscale, since suspensions containing solid nano-sized particles (nanofluids) or liquid droplets (nanoemulsions) have previously shown significantly enhanced convective heat transfer in several studies [6][7][8][9][10][11][12]19]. In addition, the smaller scale of particles may improve the stability of the fluids.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermal properties and convective heat transfer of phase changing paraffin nanofluids

Mikkola

Puupponen

Saari

et al. 2017

International Journal of Thermal Sciences

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THERMAL PROPERTIES AND CONVECTIVE HEAT TRANSFER PERFORMANCE OF SOLID-LIQUID PHASE CHANGING PARAFFIN NANOFLUIDSWe aim to combine these two concepts for the first time by studying fluids containing nano-sized phase changing particles. In this study, the convective heat transfer performance and the thermal properties of solidliquid phase changing paraffin nanofluids are experimentally examined. Three water-based paraffin nanofluids with particle mass fractions of 5-10% are prepared and measured with an annular tube heat exchanger. The heat transfer measurements cover both laminar and turbulent regimes with Reynolds numbers varying in the range of 700-11000. The measurements also include pressure losses in order to study the suitability of the fluids for practical forced convection applications. In addition, the fluids are characterized: latent heats, specific heats, viscosities, thermal conductivities, densities and particle size distributions are all determined experimentally. In agreement with previous studies, the nanofluids are found to exhibit Nusselt numbers clearly higher than water when compared on the basis of equal Reynolds numbers. However, the differences in Prandtl numbers are shown to explain these deviations in Nusselt numbers. Indeed, the well-known Gnielinski correlation is able to explain the results quite adequately and thus, significant anomalies in the convection heat transfer caused by neither the melting of the phase change material nor the presence of the nanoparticles are observed. However, the nanofluids have systematically slightly higher Nusselt numbers than the correlation would predict, but the deviations are within the accuracy of the correlation (10%). When compared by using equal pumping powers, the nanofluids exhibit heat transfer performance poorer than that of water. The positive impact of the latent heat is outweighed by the negative effects of the increased viscosity and decreased specific heat.

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Section: Convective Heat Transfersupporting

confidence: 70%

Section: Friction Factors and Pressure Lossesmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal properties and convective heat transfer of phase changing paraffin nanofluids

Mikkola

Puupponen

Saari

et al. 2017

International Journal of Thermal Sciences

Self Cite

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“…The rise in the convective heat transfer coefficient of nanofluids was more than the intensification in the effective thermal conductivity of nanofluids. Meriläinen et al (2013) showed the effect of particle size and shape on heat transfer characteristics and pressure losses in water-based nanofluids under turbulent flow regime. They found that on the basis of constant Reynolds number in range of 3000-10,000, average convective heat transfer coefficients of nanofluids improved up to 40% when compared to the base liquid.…”

Section: Comparison Study Among Two or More Nanoparticlesmentioning

confidence: 99%

A comprehensive review of experimental investigations of forced convective heat transfer characteristics for various nanofluids

Gupta

Arora

Kumar

et al. 2014

Int J Mech Mater Eng

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Nanofluids are suspension of nanoparticles (less than 100 nm) in the conventional base fluids. The dispersed solid metallic or non-metallic nanoparticles change the thermal properties like thermal conductivity, viscosity, specific heat, and density of the base fluid. Past studies focused on measuring the thermal properties of nanofluids. These suspended nanoparticles effectively improve the transport properties and heat transfer characteristics of the base fluids. Recently, heat transfer augmentation using suspensions of nanometre-sized solid particles in base liquids have been investigated by various research groups across the world. This paper reviews the state-of-the-art nanofluid studies in the area of forced convection heat transfer enhancement. The results for the heat transfer characteristics in internal flow with constant heat flux and constant wall temperature boundary conditions reported by various researchers have been compiled and reviewed. Further, in heat exchangers, the real boundary conditions are different from the constant heat flux and constant wall temperature boundary conditions. Over a span of 2 decades, the literature in this field is widespread; hence, this review would be useful for researchers to have a precise screening of a wide range of investigations in this area.

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“…In carrying out this research, a set of heat transfer devices, operating in the form of a closed cycle, was utilized for measuring the convection heat transfer coefficient experimentally under constant heat flux conditions. Distilled water was utilized as the base fluid and magnesium oxide nanoparticles, which have been understudied so far [16][17][18], were used for the preparation of nanofluid within the volume concentration of 0.02 to 0.12 % and for five different concentrations along with 16 different rates within the turbulent flow range and approximate Reynolds number in the range of 11,000-49,000. To experimentally measure the physical properties of the nanofluid, appropriate measurement devices were utilized.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of turbulent flow convection heat transfer of MgO/water nanofluid at low concentrations – Prediction of aggregation effect of nanoparticles

Motevasel¹

2017

IJHT

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The extent of increase in the convection heat transfer of MgO/water nanofluid was investigated at low concentrations within the range of 0.02 to 0.12 % vol, under turbulent flow and within the Reynolds number range of 11,000 to 49,000. It was found that at about 12 %, the heat transfer coefficient was increased compared with the base fluid, where on average, around 6 % increase was observed within the entire concentration range and the investigated Reynolds number. The aggregate effect of particles was examined in predicting the models for the determination of the physical properties of thermal conductivity and viscosity. It was observed that fractal models enjoy a greater accuracy when compared with other models. In addition, a model was proposed to predict the local heat transfer coefficient, in which the aggregate effect of nanoparticles was also investigated. It was observed that the relative average deviation of the proposed model is around 2.5 %, when compared with experimental values.

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Influence of particle size and shape on turbulent heat transfer characteristics and pressure losses in water-based nanofluids

Cited by 75 publications

References 20 publications

Thermal properties and convective heat transfer of phase changing paraffin nanofluids

Thermal properties and convective heat transfer of phase changing paraffin nanofluids

A comprehensive review of experimental investigations of forced convective heat transfer characteristics for various nanofluids

Experimental investigation of turbulent flow convection heat transfer of MgO/water nanofluid at low concentrations – Prediction of aggregation effect of nanoparticles

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