Mahdad Seyedi - MSc student, Tarbiat Modares University, Tehran,Iran
Mohammad Mahdi Heyhat - Assistant Professor of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
Majid Siavashi - Associate Professor of Mechanical Engineering, Iran University of Science and technology, Tehran, Iran

In this work, laminar flow forced convective heat transfer of Al2O3/water nanofluid over a rectangular fin with constant substrate temperature was investigated numerically. An empirical correlation was used for predicting the effective thermal conductivity and dynamic viscosity of nanofluids. The heat transfer coefficients of nanofluids were obtained for different nanoparticle concentrations as well as various diameters. Three different considered nanoparticle volume concentrations were 1%, 2% and 3%, while the nanoparticle diameters were 20nm, 40nm and 80nm. The results showed that heat transfer coefficient increased by increasing the concentration of nanoparticles and by decreasing the diameter of them. Numerical results emphasize the enhancement of 18% in heat transfer coefficient by using 20nm nanoparticles compared to 80nm nanoparticles.

Heat Transfer Enhancement, Nanofluids, Rectangular Fin, Nanoparticle Diameter