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Round-robin test on thermal conductivity measurement of ZnO nanofluids and comparison of experimental results with theoretical bounds.

Lee WH, Rhee CK, Koo J, Lee J, Jang SP, Choi SU, Lee KW, Bae HY, Lee GJ, Kim CK, Hong SW, Kwon Y, Kim D, Kim SH, Hwang KS, Kim HJ, Ha HJ, Lee SH, Choi CJ, Lee JH - Nanoscale Res Lett (2011)

Bottom Line: Ethylene glycol (EG)-based zinc oxide (ZnO) nanofluids containing no surfactant have been manufactured by one-step pulsed wire evaporation (PWE) method.Round-robin tests on thermal conductivity measurements of three samples of EG-based ZnO nanofluids have been conducted by five participating labs, four using accurate measurement apparatuses developed in house and one using a commercial device.The results have been compared with several theoretical bounds on the effective thermal conductivity of heterogeneous systems.

View Article: PubMed Central - HTML - PubMed

Affiliation: Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL, USA. suschoi@uic.edu.

ABSTRACT
Ethylene glycol (EG)-based zinc oxide (ZnO) nanofluids containing no surfactant have been manufactured by one-step pulsed wire evaporation (PWE) method. Round-robin tests on thermal conductivity measurements of three samples of EG-based ZnO nanofluids have been conducted by five participating labs, four using accurate measurement apparatuses developed in house and one using a commercial device. The results have been compared with several theoretical bounds on the effective thermal conductivity of heterogeneous systems. This study convincingly demonstrates that the large enhancements in the thermal conductivities of EG-based ZnO nanofluids tested are beyond the lower and upper bounds calculated using the models of the Maxwell and Nan et al. with and without the interfacial thermal resistance.

No MeSH data available.


Thermal conductivity enhancement for the 3.0 vol.% and 5.5 vol.% ZnO nanofluids as a function of temperature. (a) Thermal conductivity enhancement data for 3.0 vol.% ZnO nanofluids. (b) Thermal conductivity enhancement data for 5.5 vol.% ZnO nanofluids.
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Figure 4: Thermal conductivity enhancement for the 3.0 vol.% and 5.5 vol.% ZnO nanofluids as a function of temperature. (a) Thermal conductivity enhancement data for 3.0 vol.% ZnO nanofluids. (b) Thermal conductivity enhancement data for 5.5 vol.% ZnO nanofluids.

Mentions: Figure 4a, b shows the thermal conductivity enhancements for the 3.0 and 5.5 vol.% ZnO nanofluids that were measured at each of the five participating labs. The thermal conductivity enhancement is defined as (keff - kf)/kf, where keff and kf are the thermal conductivity of nanofluids and base fluids, respectively. Each data point represents the ratio of the mean of 10 measured enhancements to the thermal conductivity of base fluid. Error bars show measurement uncertainty determined by the participating labs as described in the previous section. Figure 4a, b indicates that the experimental thermal conductivity data show very little dependence on temperature in the 20 to 90°C range.


Round-robin test on thermal conductivity measurement of ZnO nanofluids and comparison of experimental results with theoretical bounds.

Lee WH, Rhee CK, Koo J, Lee J, Jang SP, Choi SU, Lee KW, Bae HY, Lee GJ, Kim CK, Hong SW, Kwon Y, Kim D, Kim SH, Hwang KS, Kim HJ, Ha HJ, Lee SH, Choi CJ, Lee JH - Nanoscale Res Lett (2011)

Thermal conductivity enhancement for the 3.0 vol.% and 5.5 vol.% ZnO nanofluids as a function of temperature. (a) Thermal conductivity enhancement data for 3.0 vol.% ZnO nanofluids. (b) Thermal conductivity enhancement data for 5.5 vol.% ZnO nanofluids.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211320&req=5

Figure 4: Thermal conductivity enhancement for the 3.0 vol.% and 5.5 vol.% ZnO nanofluids as a function of temperature. (a) Thermal conductivity enhancement data for 3.0 vol.% ZnO nanofluids. (b) Thermal conductivity enhancement data for 5.5 vol.% ZnO nanofluids.
Mentions: Figure 4a, b shows the thermal conductivity enhancements for the 3.0 and 5.5 vol.% ZnO nanofluids that were measured at each of the five participating labs. The thermal conductivity enhancement is defined as (keff - kf)/kf, where keff and kf are the thermal conductivity of nanofluids and base fluids, respectively. Each data point represents the ratio of the mean of 10 measured enhancements to the thermal conductivity of base fluid. Error bars show measurement uncertainty determined by the participating labs as described in the previous section. Figure 4a, b indicates that the experimental thermal conductivity data show very little dependence on temperature in the 20 to 90°C range.

Bottom Line: Ethylene glycol (EG)-based zinc oxide (ZnO) nanofluids containing no surfactant have been manufactured by one-step pulsed wire evaporation (PWE) method.Round-robin tests on thermal conductivity measurements of three samples of EG-based ZnO nanofluids have been conducted by five participating labs, four using accurate measurement apparatuses developed in house and one using a commercial device.The results have been compared with several theoretical bounds on the effective thermal conductivity of heterogeneous systems.

View Article: PubMed Central - HTML - PubMed

Affiliation: Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL, USA. suschoi@uic.edu.

ABSTRACT
Ethylene glycol (EG)-based zinc oxide (ZnO) nanofluids containing no surfactant have been manufactured by one-step pulsed wire evaporation (PWE) method. Round-robin tests on thermal conductivity measurements of three samples of EG-based ZnO nanofluids have been conducted by five participating labs, four using accurate measurement apparatuses developed in house and one using a commercial device. The results have been compared with several theoretical bounds on the effective thermal conductivity of heterogeneous systems. This study convincingly demonstrates that the large enhancements in the thermal conductivities of EG-based ZnO nanofluids tested are beyond the lower and upper bounds calculated using the models of the Maxwell and Nan et al. with and without the interfacial thermal resistance.

No MeSH data available.