WSEAS Transactions on Heat and Mass Transfer
Print ISSN: 1790-5044, E-ISSN: 2224-3461
Volume 8, 2013
Influence of Rheological Behavior of Nanofluid on Heat Transfer
Authors: ,
Abstract: The influence of rheological behavior of nanofluid on heat transfer is established. A comparative analysis is presented for heat transfer behavior of Newtonian and non-Newtonian model of nanofluid for natural convection. Ostwald–de Waele model for non-Newtonian fluid is used for calculating the shear stresses from the velocity gradients. Brinkmann model is used for incorporating the influence of volume fraction on viscosity for Newtonian model. The numerical analysis is presented for Rayleigh number (Ra) in the range of 104 to 106 and nanoparticle volume fraction (ϕ) in the range of 0.05% to 5%. For non-Newtonian model, a reduction in the average Nusselt number is observed with increase in volume fraction (ϕ) for a particular Rayleigh number. On the other hand, augmentation of Nusselt number is observed for Newtonian model. It is also observed that heat transfer rate increases with the increase in Rayleigh number for both the cases, though the augmentation in case of Newtonian model is more compared to Non-Newtonian model.