International Scientific Journal

Thermal Science - Online First

online first only

Toward improved heat dissipation of the turbulent regime over backward-facing step for the alumina-water nanofluids ― an experimental approach

Experimental study of nanofluid flow and heat transfer to fully developed turbulent forced convection flow in a uniformly heated tubular horizontal backward-facing step has reported in the present study. To study the forced convective heat transfer coefficient in the turbulent regime, an experimental study is performed at a different weight concentration of Al2O3 nanoparticles. The experiment had conducted for water and Alumina-water nanofluid for the concentration range of 0 to 0.1 wt.% and Reynolds number of 4000 to 16000. The average heat transfer coefficient ratio increases significantly as Reynolds number increasing, increased from 9.6% at Re of 4000 to 26.3% at Re of 16,000 at the constant weight concentration of 0.1%. Alumina-water nanofluid exhibited excellent thermal performance in the tube with a backward-facing step in comparison to distilled water. However, the pressure losses increased with the increase of the Reynolds number and/or the weight concentrations, but the enhancement rates were insignificant.
PAPER REVISED: 2018-05-15
PAPER ACCEPTED: 2018-07-07
  1. H. Mohammed, A. Al‐aswadi, H. Abu‐Mulaweh, N. Shuaib, Influence of nanofluids on mixed convective heat transfer over a horizontal backward‐facing step, Heat Transfer—Asian Research 40 (2011) 287-307.
  2. H. Abu-Mulaweh, A review of research on laminar mixed convection flow over backward-and forward-facing steps, International Journal of Thermal Sciences 42 (2003) 897-909.
  3. H. Masuda, A. Ebata, K. Teramae, Alteration of thermal conductivity and viscosity of liquid by dispersing ultra-fine particles. Dispersion of Al2O3, SiO2 and TiO2 ultra-fine particles, (1993).
  4. P. Keblinski, S. Phillpot, S. Choi, J. Eastman, Mechanisms of heat flow in suspensions of nano-sized particles (nanofluids), International journal of heat and mass transfer 45 (2002) 855-863.
  5. H.-q. Xie, J.-c. Wang, T.-g. Xi, Y. Liu, Thermal conductivity of suspensions containing nanosized SiC particles, International Journal of Thermophysics 23 (2002) 571-580.
  6. B.-X. Wang, L.-P. Zhou, X.-F. Peng, A fractal model for predicting the effective thermal conductivity of liquid with suspension of nanoparticles, International Journal of Heat and Mass Transfer 46 (2003) 2665-2672.
  7. S. Özerinç, S. Kakaç, A.G. Yazıcıoğlu, Enhanced thermal conductivity of nanofluids: a state-of-the-art review, Microfluidics and Nanofluidics 8 (2010) 145-170.
  8. M.P. Beck, Y. Yuan, P. Warrier, A.S. Teja, The effect of particle size on the thermal conductivity of alumina nanofluids, Journal of Nanoparticle Research 11 (2009) 1129-1136.
  9. C. Murugesan, S. Sivan, Limits for thermal conductivity of nanofluids, Thermal Science 14 (2010) 65-71.
  10. H. Chen, S. Witharana, Y. Jin, C. Kim, Y. Ding, Predicting thermal conductivity of liquid suspensions of nanoparticles (nanofluids) based on rheology, Particuology 7 (2009) 151-157.
  11. K. Solangi, S. Kazi, M. Luhur, A. Badarudin, A. Amiri, R. Sadri, M. Zubir, S. Gharehkhani, K. Teng, A comprehensive review of thermo-physical properties and convective heat transfer to nanofluids, Energy 89 (2015) 1065-1086.
  12. H. Mohammed, A. Al-Aswadi, N. Shuaib, R. Saidur, Convective heat transfer and fluid flow study over a step using nanofluids: a review, Renewable and Sustainable Energy Reviews 15 (2011) 2921-2939.
  13. R. Sadri, K. Zangeneh Kamali, M. Hosseini, N. Zubir, S.N. Kazi, G. Ahmadi, M. Dahari, N.M. Huang, A.M. Golsheikh, Experimental study on thermo-physical and rheological properties of stable and green reduced graphene oxide nanofluids: Hydrothermal assisted technique, Journal of Dispersion Science and Technology 38 (2017) 1302-1310.
  14. M. Hosseini, R. Sadri, S.N. Kazi, S. Bagheri, N. Zubir, C. Bee Teng, T. Zaharinie, Experimental Study on Heat Transfer and Thermo-Physical Properties of Covalently Functionalized Carbon Nanotubes Nanofluids in an Annular Heat Exchanger: A Green and Novel Synthesis, Energy & Fuels (2017).
  15. L. Boelter, G. Young, H. Iversen, An Investigation of Aircraft Heaters XXVII: Distribution of Heat-transfer Rate in the Entrance Section of a Circular Tube, (1948).
  16. A. Ede, C. Hislop, R. Morris, Effect on the local heat-transfer coefficient in a pipe of an abrupt disturbance of the fluid flow: abrupt convergence and divergence of diameter ratio 2/1, Proceedings of the Institution of Mechanical Engineers 170 (1956) 1113-1130.
  17. R. Seban, Heat transfer to separated and reattached subsonic turbulent flows obtained downstream of a surface step, Journal of the Aerospace Sciences (2012).
  18. D. Abbott, S. Kline, Experimental investigation of subsonic turbulent flow over single and double backward facing steps, Journal of basic engineering 84 (1962) 317-325.
  19. E. Filetti, W.M. Kays, Heat transfer in separated, reattached, and redevelopment regions behind a double step at entrance to a flat duct, Journal of Heat transfer 89 (1967) 163-167.
  20. R.J. Goldstein, V. Eriksen, R. Olson, E. Eckert, Laminar separation, reattachment, and transition of the flow over a downstream-facing step, Journal of Basic Engineering 92 (1970) 732-739.
  21. E. Abu-Nada, Application of nanofluids for heat transfer enhancement of separated flows encountered in a backward facing step, International Journal of Heat and Fluid Flow 29 (2008) 242-249.
  22. A.A. Al-aswadi, H.A. Mohammed, N.H. Shuaib, A. Campo, Laminar forced convection flow over a backward facing step using nanofluids, International Communications in Heat and Mass Transfer 37 (2010) 950-957.
  23. A.S. Kherbeet, H.A. Mohammed, B.H. Salman, The effect of nanofluids flow on mixed convection heat transfer over microscale backward-facing step, International Journal of Heat and Mass Transfer 55 (2012) 5870-5881.
  24. A.S. Kherbeet, H. Mohammed, K.M. Munisamy, B. Salman, Combined convection nanofluid flow and heat transfer over microscale forward-facing step, International Journal of Nanoparticles 7 (2014) 1-25.
  25. A.S. Kherbeet, H.A. Mohammed, K.M. Munisamy, B.H. Salman, The effect of step height of microscale backward-facing step on mixed convection nanofluid flow and heat transfer characteristics, International Journal of Heat and Mass Transfer 68 (2014) 554-566.
  26. A.S. Kherbeet, H. Mohammed, B. Salman, H.E. Ahmed, O.A. Alawi, M. Rashidi, Experimental study of nanofluid flow and heat transfer over microscale backward-and forward-facing steps, Experimental Thermal and Fluid Science 65 (2015) 13-21.
  27. W. Yu, D.M. France, D.S. Smith, D. Singh, E.V. Timofeeva, J.L. Routbort, Heat transfer to a silicon carbide/water nanofluid, International Journal of Heat and Mass Transfer 52 (2009) 3606-3612.
  28. W. Yu, D.M. France, E.V. Timofeeva, D. Singh, J.L. Routbort, Comparative review of turbulent heat transfer of nanofluids, International Journal of Heat and Mass Transfer 55 (2012) 5380-5396.
  29. S.M. Ahmed, S.N. Kazi, G. Khan, R. Sadri, M. Dahari, M.N.M. Zubir, M. Sayuti, P. Ahmad, R. Ibrahim, Effect of various refining processes for Kenaf Bast non-wood pulp fibers suspensions on heat transfer coefficient in circular pipe heat exchanger, Heat and Mass Transfer (2017).
  30. A.S. Kherbeet, H. Mohammed, B. Salman, The effect of nanofluids flow on mixed convection heat transfer over microscale backward-facing step, International Journal of Heat and Mass Transfer 55 (2012) 5870-5881.
  31. S. Choi, Z. Zhang, W. Yu, F. Lockwood, E. Grulke, Anomalous thermal conductivity enhancement in nanotube suspensions, Applied physics letters 79 (2001) 2252-2254.
  32. S. Lee, S.-S. Choi, S. Li, and, J. Eastman, Measuring thermal conductivity of fluids containing oxide nanoparticles, Journal of Heat transfer 121 (1999) 280-289.
  33. A. Amiri, M. Shanbedi, A.R. Rafieerad, M.M. Rashidi, T. Zaharinie, M.N.M. Zubir, S.N. Kazi, B.T. Chew, Functionalization and exfoliation of graphite into mono layer graphene for improved heat dissipation, Journal of the Taiwan Institute of Chemical Engineers 71 (2017) 480-493.
  34. R. Sadri, M. Hosseini, S.N. Kazi, S. Bagheri, N. Zubir, G. Ahmadi, M. Dahari, T. Zaharinie, A novel, eco-friendly technique for covalent functionalization of graphene nanoplatelets and the potential of their nanofluids for heat transfer applications, Chemical Physics Letters 675 (2017) 92-97.
  35. D. Wen, Y. Ding, Effect of particle migration on heat transfer in suspensions of nanoparticles flowing through minichannels, Microfluidics and Nanofluidics 1 (2005) 183-189.
  36. S.J. Aravind, P. Baskar, T.T. Baby, R.K. Sabareesh, S. Das, S. Ramaprabhu, Investigation of structural stability, dispersion, viscosity, and conductive heat transfer properties of functionalized carbon nanotube based nanofluids, The Journal of Physical Chemistry C 115 (2011) 16737-16744.
  37. A. Amiri, H.K. Arzani, S. Kazi, B. Chew, A. Badarudin, Backward-facing step heat transfer of the turbulent regime for functionalized graphene nanoplatelets based water-ethylene glycol nanofluids, International Journal of Heat and Mass Transfer 97 (2016) 538-546.
  38. S.M. Ahmed, S.N. Kazi, G. Khan, M. Dahari, M.N.M. Zubir, P. Ahmad, E. Montazer, Experimental investigation on momentum and drag reduction of Malaysian crop suspensions in closed conduit flow, IOP Conference Series: Materials Science and Engineering 210 (2017) 012065.