Numerical Study of Forced Convective Heat Transfer of Nanofluids inside a Vertical Tube
Pages : 10-15
In this study, laminar forced convective heat transfer of nanofluids consisted of alumina/water and zirconia/water through a vertical tube under constant heat flux boundary condition was investigated numerically. Single phase and two phase mixture models were used for analyzing thermal behavior of nanofluids. Furthermore, effects of Reynolds number, nanoparticle types and nanoparticles volume fraction on the convective heat transfer coefficient were studied. The results of single phase and mixture models were compared with the experimental data. The results of the mixture model for prediction of the convective heat transfer coefficient showed better agreement with the experimental data, while the prediction of nanofluid mean bulk temperature distribution inside the tube by the single phase model was better than the mixture model compared to the experimental data. In addition, according to the results of numerical data, the convective heat transfer of nanofluids is higher than that of water similar to the experimental data. The average relative error for predicting convective heat transfer coefficient between experimental data and single-phase model was 13% and 8% for alumina/water and zirconia/water nanofluids, respectively while for mixture model was 8% and 5%.
Keywords: Nanofluid, Forced convection, Heat transfer coefficient, Single phase model and Mixture model.
Article published in International Journal of Thermal Technologies, Vol.3, No.1 (March- 2013)