Development of new correlations for convective heat transfer and friction factor in turbulent regime for nanofluids

Vajjha, Ravikanth S.; Das, Debendra K.; Kulkarni, Devdatta

doi:10.1016/j.ijheatmasstransfer.2010.06.032

Cited by 394 publications

(175 citation statements)

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“…Aluminum oxide and copper oxide nanoparticles at concentrations ranging from 0 to 6% by volume were assessed. The fluid properties were taken at 298K (76.7°F), a temperature where properties are available in the existing databases 3,4 , that is approximately equal to the average inner loop fluid temperatures. The properties for each nanofluid are shown in Table 2.…”

Section: Study Methodologymentioning

confidence: 99%

Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

Ungar

Erickson

2011

AIAA SPACE 2011 Conference &Amp; Exposition

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The addition of metallic nanoparticles to a base heat transfer fluid can dramatically increase its thermal conductivity. These nanofluids have been shown to have advantages in some heat transport systems. Their enhanced properties can allow lower system volumetric flow rates and can reduce the required pumping power. Nanofluids have been suggested for use as working fluids for spacecraft Active Thermal Control Systems (ATCSs). However, there are no studies showing the end-to-end effect of nanofluids on the design and performance of spacecraft ATCSs.In the present work, a parametric study is performed to assess the use of nanofluids in a spacecraft ATCSs. The design parameters of the current Orion capsule and the tabulated thermophysical properties of nanofluids are used to assess the possible benefits of nanofluids and how their incorporation affects the overall design of a spacecraft ATCS. The study shows that the unique system and component-level design parameters of spacecraft ATCSs render them best suited for pure working fluids. The addition of nanoparticles to typical spacecraft thermal control working fluids actually results in an increase in the system mass and required pumping power. The addition of metallic nanoparticles to a base heat transfer fluid can substantially increase its thermal conductivity. These nanofluids have been shown to have advantages in some heat transport systems. Their thermal properties allow the system volumetric flow rate to be reduced, thus reducing the required pumping power. Nanofluids have been suggested as working fluids in spacecraft Active Thermal Control Systems (ATCSs). However, spacecraft ATCSs are unique in that they have stringent temperature control requirements and use specialized heat transfer devices. In the present work, a parametric study was performed to assess the use of nanofluids in spacecraft ATCSs. The tabulated thermophysical properties of various nanofluids, the design requirements of NASA's Orion ATCS and the performance parameters of its key heat transfer components were used to assess the effects of the incorporation of nanofluids. The study shows that the unique system and component-level design parameters of spacecraft ATCSs do not lend themselves to the use of nanofluids. The addition of nanoparticles to typical spacecraft internal flow loop working fluids actually results in an increase in either the system mass or the required pumping power, the opposite of the hoped-for effect. The intermediate results obtained in the study also suggest that that the addition of nanoparticles to an external ATCS loop is not likely to result in a significant overall system benefit.

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Section: Study Methodologymentioning

confidence: 99%

Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

Ungar

Erickson

2011

AIAA SPACE 2011 Conference &Amp; Exposition

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“…The numerical results employing the property relations indicate that the experiments could have been undertaken at 30 o C and 70 o C by Kulkarni et al [10] and Vajjha et al [11] respectively.…”

Section: Resultsmentioning

confidence: 96%

“…(7) and (14) given by Sharma [15] for base liquid and nanofluid respectively are in good agreement with the experimental data with a maximum deviation of 14% among all concentrations, shown plotted in Fig.2. The experimental determination of heat transfer coefficients with base liquid EG-water 60:40 mixture were performed by Kulkarni et al [10] and Vajjha et al [11] in the turbulent range Fig.1 Comparison of thermal conductivity data with theory Fig.2 Comparison of viscosity data with theory of Reynolds Number at unspecified temperatures. The temperatures are predicted using the theoretical results which is observed to be in agreement with the base liquid experimental ata at 30 o C and 70 o C for Kulkarni et al [10] and Vajjha et al [11] with a maximum deviation of 20% and 15% respectively as shown plotted in Fig.3.…”

Section: Resultsmentioning

confidence: 99%

“…The heat transfer enhancement reported by Vajjha et al [11] is 82% with Al2O3 nanofluid while Kulkarni et al [10] reported only 16% with SiO2 nanofluid at the same volume concentration of 10%. The reason for the deviation in heat transfer enhancement with Al2O3 and SiO2 nanofluids has not been explained by the authors in the turbulent range and hence numerical analysis is undertaken in the turbulent range of Reynolds number for EG-water mixtures of 60:40 ratio.…”

Section: Introductionmentioning

confidence: 90%

“…Experiments for the determination of nanofluid forced convection heat transfer coefficients in the turbulent range are undertaken with Al2O3 (45nm), CuO (29nm), and SiO2 (20, 50, 100nm) for a maximum concentration of 10.0% for temperature varying from 20-90 o C by Vajjha and Das [11] in base liquid EG-water mixture in 60:40 ratio. They have reported an enhancement of 81.74% in heat transfer for Al2O3 nanofluid at a concentration of 10%.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of nanofluid heat transfer properties with theory using generalized property relations for EG-water mixture

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Energy Transfers by Convection

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Development of new correlations for convective heat transfer and friction factor in turbulent regime for nanofluids

Cited by 394 publications

References 17 publications

Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

Comparison of nanofluid heat transfer properties with theory using generalized property relations for EG-water mixture

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