A comparison of theoretical and empirical viscosity models for a nanofluid in a non-isothermal channel flow

Abstract

This study investigates the nanofluid for a nonisothermal channel flow under the effect of a constant pressure gradient acting along the channel axis. In the present study, the theoretical and experimental models commonly encountered in the literature (Einstein, Batchelor, Brinkman, Wang, Chen and Heyhat models) are compared by observing temperature and velocity profiles and are examined for compliance with each other. The effects of volume fraction, pressure gradient and Reynolds numbers on velocity and temperature profiles are investigated for the alumina-water nanofluid. Twodimensional, non-isothermal, hydrodynamically and thermally fully developed, steady flow of an incompressible fluid inside a channel is taken into consideration. Upper and lower walls of the channel are kept at the same constant heat flux and it is assumed that alumina-water nanofluid is a homogeneous and single-phase fluid. Discretization is performed using a Pseudospectral technique based on Chebyshev polynomial expansions. The resulting nonlinear, coupled boundary value problem is numerically solved using FORTRAN computer program. © Copyright 2017 American Scientific Publishers All rights reserved.