Heat transfer in a vertical rectangular duct filled with a nanofluid for variable viscosity

Abstract

Flow and heat transfer in a vertical rectangular duct filled with a nanofluid is studied numerically assuming the viscosity to be dependent on temperature. The transport equations which are highly nonlinear and coupled are solved numerically using finite difference method. The obtained numerical solutions are presented pictorially for various non-dimensional parameters governing the flow. It is found that the copper nanoparticle shows the optimum values for velocity and temperature when compared to diamond and TiO2 for all values of viscosity variation parameter. The effects of the governing parameters on the physical characteristics such as the volumetric flow rate, skin friction, and the rate of heat transfer are also computed and are tabulated. The range of the parameters considered are Gr = 10, Br = 1, A = 1, ? = 0.02 for BV =?0.5, 0.0, 0.5 using Copper as nanoparticle. The results show that the rate of heat transfer is more for nanofluid when compared to pure fluid. The positive values of viscosity variation parameter show more contours in the right half region and negative values of the viscosity variation parameter show more velocity contours in the left half region of the duct. The rate of heat transfer for copper nanoparticle is found to be more than that for TiO2 at both the plates. © 2017 by American Scientific Publishers All rights reserved.