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http://dx.doi.org/10.3795/KSME-B.2011.35.3.279

Onset of Natural Convection in Transient Hot Wire Device for Measuring Thermal Conductivity of Nanofluids  

Lee, Seung-Hyun (School of Mechanical and Aerospace Engineering, Korea Aerospace Univ.)
Kim, Hyun-Jin (School of Mechanical and Aerospace Engineering, Korea Aerospace Univ.)
Jang, Seok-Pil (School of Mechanical and Aerospace Engineering, Korea Aerospace Univ.)
Publication Information
Transactions of the Korean Society of Mechanical Engineers B / v.35, no.3, 2011 , pp. 279-285 More about this Journal
Abstract
We perform a numerical study to determine the time of onset of natural convection in a transient hot wire (THW) device for measuring the thermal conductivity of nanofluids. The samples used in this simulation are water-based $Al_2O_3$ nanofluids with volume fractions of 1%, 4%, and 10%, and the properties are calculated by theoretical models and experimental correlations. The THW apparatus using coated wire is modeled by the control-volume-based finite difference method, and the start of natural convection is determined by observing the temperature rise of the wire under a gravity field. The onset time is 11.5 s for water and 41.6 s for water-based $Al_2O_3$ nanofluids predicted by Maxwell thermal conductivity model with a 10% volume fraction. We confirm that the onset time of natural convection of nanofluids in the cylinder increases with the nanoparticle volume fraction. We suggest a correlation for predicting the onset time on the basis of the numerical results. Finally, it is shown that the measurement error due to natural convection is negligible if the measurement using the transient hot wire method is completed before the onset of natural convection in the base fluid.
Keywords
Onset Time of Natural Convection; Transient Hot Wire Method; Nanofluids; Thermal conductivity; $Al_2O_3$ Nanoparticles;
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1 Hwang, K. S., Lee, J.-H., Jang, S. P., 2007, “Buoyancy-Driven Heat Transfer of Water-Based $Al_2O_3$ Nanofluids in a Rectangular Cavity,” International Journal of Heat and Mass Transfer, Vol. 50, No. 19-20, pp.4003-4010.   DOI   ScienceOn
2 Assael, M. J., Karagiannidis, L., Malamataris, N. and Wakeham, W. A., 1998, "The Transient Hot-Wire Technique:A Numerical Approach," International Journal of Thermophysics, Vol. 19, No. 2.
3 Mohammadi, S. S., Graboski, M. S. and Sloan, E. D., 1981, “A Mathematical Model of a Ramp Forced Hot- Wire Thermal Conductivity Instrument,” International Journal of Heat and Mass Transfer, Vol. 24, No. 4, pp. 671-683.   DOI   ScienceOn
4 Rusconi R., Williams, W. C., Buongiorno, J., Piazza, R. and Hu, L.-W., 2007, "Numerical Analysis of Convective Instabilities in a Transient Short-Hot-Wire Setup for Measurement of Liquid Thermal Conductivity," Int. J. Thermophys., Vol. 28, No. 4,.
5 Carslaw, H. S. and Jaeger, J. C., 1959, Conduction of Heat in Solids, 2nd ed., Oxford University Press, London.
6 Nagasaka, Y. and Nagashima, A., 1981, “Absolute Measurement of the Thermal Conductivity of Electrically Conducting Liquids by the Transient Hot- Wire Method,” Journal of Physics E: Scientific Instruments, Vol. 14, No. 12, pp. 1435-1440.   DOI   ScienceOn
7 Zhou, S.-Q. and Ni, R., 2008, “Measurement of the Specific Heat Capacity of Water-Based $Al_2O_3$ Nanofluid,” Applied Physics Letter, Vol. 92, No. 9, pp. 093123.   DOI   ScienceOn
8 Maxwell, J. C., 1873, A Treatise on Electricity and Magnetism, Oxford University Press, London, 1st ed., pp. 360-366.
9 Jang, S. P. and Choi, S.U.S., 2004, “Role of Brownian Motion in the Enhanced Thermal Conductivity of Nanofluids,” Applied Physics Letter, Vol. 84, No.21, pp. 4316-4318.   DOI   ScienceOn
10 Pak, B. C. and Cho, Y. I., 1998, “Hydrodynamic and Heat Transfer Study of Dispersed Fluids with Submicron Metallic Oxide Particles,” Experimental Heat Transfer, Vol. 11, No. 2, pp. 151-170.   DOI   ScienceOn
11 Bejan, A., 2004, Convection Heat Transfer, John Wiley&Sons, 3rd ed., p.222.
12 Xie, H., Wang, J., Xi, T., Liu, Y., Ai, F. and Wu, Q., 2002, “Thermal Conductivity Enhancement of Suspensions Containing Nanosized Alumina Particles,” Journal of Applied Physics, Vol. 91, No. 7, pp. 4568-4572.   DOI   ScienceOn
13 Zhang, X., Gu, H. and Fujii, M., 2006, “Effective Thermal Conductivity and Thermal Diffusivity of Nanofluids Containing Spherical and Cylindrical Nanoparticles,” Journal of Applied Physics, Vol. 100 No.4, pp. 044325.   DOI   ScienceOn
14 Li, C. H., Williams, W., Buongiorno, J., Hu, L.-W. and Peterson, G. P., 2008, “Transient and Steady-State Experimental Comparison Study of Effective Thermal Conductivity of $Al_2O_3$/Water Nanofluids,” Journal of Heat Transfer Trans. of the ASME, Vol. 130, No. 4, pp. 042407.   DOI   ScienceOn
15 Stalhane, B. and Pyk, S., 1931, “The New Method for Determining the Coefficients of Thermal Conductivity,” Technisk Tidskrift, Vol. 61, p. 389.
16 Beck, M. P., Yuan, Y., Warrier, P. and Teja, A.S., 2010 “The Thermal Conductivity of Alumina Nanofluids in Water, Ethylene Glycol, and Ethylene Glycol+Water Mixtures,” Journal of Nanoparticle Research, Vol. 12, No. 4, pp.1469-1477.   DOI
17 Yu, W., France, D. M., Routbort, J. L. and Choi , S. U. S., 2008, “Review and Comparison of Nanofluid Thermal Conductivity and Heat Transfer Enhancements,” Heat Transfer Engineering, Vol. 29., No. 5, pp.432-460.   DOI   ScienceOn
18 Buongiorno, J. et al., 2009, “A Benchmark Study on the Thermal Conductivity of Nanofluids,” Journal of Applied Physics, Vol. 106, No. 9, pp. 094312.   DOI   ScienceOn
19 Wakeham, W. A., Nagashima, A. and Sengers, J. V., 1991, Measurement of the Transport Properties of Fluids, Blackwell Science, London, Chap. 7.
20 Healy J. J., de Groot J. J. and Kestin, J., 1976, “The Theory of the Transient Hot-Wire Method for Measuring Thermal Conductivity,” Physica, Vol. 82, No. 2, pp. 392-408.
21 Eastman, J. A., Choi, S. U. S, Li, S., Thompson, L. J. and Lee, S., 1997, “Enhanced Thermal Conductivity Through the Development of Nanofluids,” Proceeding of the Symposium on Nanophase and Nanocomposite Materials II, Material Research Society, Boston, 1997, Vol. 457, pp. 3-11.
22 Choi, S. U. S., 2009, “Nanofluids: From Vision to Reality Through Research,” Journal of Heat Transfer Trans. of the ASME, Vol. 131, No. 3, pp. 033106-1-033106-9.   DOI   ScienceOn
23 Lee, S., Choi, S. U. S., Li, S. and Eastman, J. A., 1999, “Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles,” Journal of Heat Transfer, Trans. of the ASME, Vol. 121, No. 2, pp. 280-289.   DOI