EXPERIMENTAL STUDY ON DENSITY, THERMAL CONDUCTIVITY, SPECIFIC HEAT AND VISCOSITY OF WATER - ETHYLENE GLYCOL MIXTURE DISPERSED WITH CARBON NANOTUBES

Abstract

This article presents the effect of adding multi wall carbon nanotubes (MWCNT) in water - ethylene glycol mixture on density and various thermophysical properties such as thermal conductivity, specific heat and viscosity. Density of nanofluids was measured using standard volumetric flask method and the data showed a good agreement with the mixing theory. The maximum thermal conductivity enhancement of 11 % was noticed for the nanofluids with 0.9 wt. %. Due to lower specific heat of the MWCNT, the specific heat of the nanofluids decreased in proportion with the MWCNT concentration. The rheological analysis showed that the transition region from shear thinning to Newtonian extended to the higher shear stress range compared to that of base fluids. Viscosity ratio of the nanofluids augmented anomalously with respect to increase in temperature and about 2.25 fold increase was observed in the temperature range of 30 - 40 ˚C. The modified model of Maron and Pierce predicted the viscosity of the nanofluids with the inclusion of effect of aspect ratio of MWCNT and nanoparticle aggregates.

Keywords

Dates

  • Submission Date2014-10-15
  • Revision Date2014-12-27
  • Acceptance Date2015-03-08
  • Online Date2015-03-08

DOI Reference

10.2298/TSCI141015028G

References

  1. Ahuja, A.S., Augmentation of heat transport in laminar flow of polystyrene suspensions. I. Experiments and results, Journal Applied Physics, 46 (1975), 8, pp. 3408-3416.
  2. Choi, U.S., Eastman, J.A., Enhancing thermal conductivity of fluids with nanoparticles, ASME International Mechanical Engineering Congress and Exhibition, San Francisco, Calif, USA, 1995.
  3. Iijima, S., Helical microtubules of graphitic carbon, Nature, 354 (1991) pp. 56-58.
  4. Wang, H., Dispersing carbon nanotubes using surfactants, Current Opinion in Colloid and Interface Science, 14 (2009), 5, pp. 364-371.
  5. Shanthi, R., Shanmugasundaram, A., Velraj, R., Heat transfer enhancement using nanofluids - An overview, Thermal Science, 16 (2012), 2, pp. 423-444.
  6. Das, S.K., Choi, U.S., Patel. H.E., Heat transfer in nanofluids - A review, Heat Transfer Engineering, 27, (2006), 10, pp. 3-19.
  7. Ding et al., Heat transfer of aqueous suspensions of carbon nanotubes (CNT nanofluids), International Journal of Heat and Mass Transfer, 49 (2006), pp. 240-250.
  8. Halelfadl, S., Estellé, P., Aladag, B., Doner, N., Maré, T., Viscosity of carbon nanotubes water-based nanofluids: Influence of concentration and temperature, International Journal of Thermal Sciences 71 (2013) 111-117.
  9. Kumaresan, V., Mohaideen Abdul Khader, S., Karthikeyan, S., Velraj, R., Convective heat transfer characteristics of CNT nanofluids in a tubular heat exchanger of various lengths for energy efficient cooling/heating system, International Journal of Heat and Mass Transfer, 60 (2013), pp. 413-421.
  10. Zhou, S-Q., Ni, R., Measurement of the specific heat of water-based Al2O3 nanofluid, Applied Physics Letter, 92 (2008); dx.doi.org/10.1063/1.2890431
  11. Pak, B.C., Cho, Y.I., Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles, Experimental Heat Transfer, 11 (1998), 2, pp. 151-170.
  12. Moffat, R.J., Describing the uncertainties in experimental results, Experimental Thermal and Fluid Science, 1 (1988), 1, pp. 3-17.
  13. Alexiadis, A., Kassinos, S., The density of water in carbon nanotubes, Chemical Engineering Science, 63 (2008), 8, pp. 2047-2056.
  14. Xie, H., Chen, L., Adjustable thermal conductivity in carbon nanotube nanofluids, Physics Letter A, 373 (2009), 21, pp. 1861-1864.
  15. Chen, L., Xie, H., Li, Y., Yu, W., Nanofluids containing carbon nanotubes treated by mechanochemical reaction, Thermochimica Acta, 477 (2008), 1-2, pp. 21-24.
  16. Munkhbayar et al., An experimental study of the planetary ball milling effect on dispersibility and thermal conductivity of MWCNTs-based aqueous nanofluids, Materials Research Bulletin, 47 (2012), 12, 4187 - 4196.
  17. American Society of Heating, Refrigerating and Air-conditioning Engineers, ASHRAE Handbook: Fundamentals, Atlanta, GA, USA, 1997.
  18. Brinkman, H.C., The viscosity of concentrated suspensions and solutions, Journal of Chemical Physics, 20 (1952), 4, pp. 571-581.
  19. Brenner, H., Condiff, D.W., Transport mechanics in systems of orientable particles. Part IV Convective transport, Journal of Colloid and Interface Science, 47 (1974), 1, pp. 199-264.
  20. Maron, S.H., Pierce, P.E., Application of Ree-Eyring generalized flow theory to suspensions of spherical particles, Journal of Colloid Science, 11 (1956), 1, pp. 80-95.
  21. Pabst, W., Gregorova, E., Berthold, C., Particle shape and suspension rheology of short-fiber systems, Journal of the European Ceramic Society, 26 (2006), 1-2, pp. 149-160.