8-9th August, 2008 School of Materials Science & Nanotechnology,Jadavpur University
Comparison of Heat Transfer Enhancement due to Laminar Flow of Newtonian and non-Newtonian Nanofluid through Two Isothermally Heated Parallel Plates
Apurba Kumar Santraa*, Swarnendu Senb and Niladri Chakrabortya
a Department of Power Engineering, Jadavpur University, Salt Lake Campus, Block – LB, Plot-8, Sector – III, Salt Lake, Kolkata – 700 098, India.
b Department of Mechanical Engineering, Jadavpur University, Kolkata- 700 032, India.
* Correspondent author, e_mail: aksantra@pe.jusl.ac.in
Ph: +91 33 2335 5813/ 5215 ; Fax: +91 33 2335 7254
Abstract
Heat transfer augmentation due to laminar flow of copper-water nanofluid in a two-dimensional horizontal rectangular duct has been studied numerically. The top and bottom walls are two symmetric heat sources, which are kept at constant temperature. The governing transport equations have been discretized using a finite volume approach and have been solved iteratively The correlation proposed by Patel et al. has been used to determine the effective thermal conductivity of nanofluid, which is a function of particle diameter as well as temperature. Nanofluid has been considered Newtonian as well as non-Newtonian. For Newtonian nanofluid Brinkman viscosity model has been used, while for non-Newtonian nanofluid Ostwald-de Waele model has been used. Study for a wide range of Reynolds number (Re= 5 to 1500) and solid volume fraction (0.00 ≤φ≤ 0.050) shows that the heat transfer augmentation is almost same for both the cases The rate of heat transfer increases with the increase in flow as well as increase in solid volume fraction of the nanofluid. The wall shear stress is much higher for low Re for non-Newtonian fluid and it increases with φ. But for higher Re it decreases with φ. For Newtonian nanofluid there is almost no change in wall shear stress with φ.
Keywords: Nanofluid; Rectangular Duct; Laminar Flow; Newtonian; Non-Newtonian

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