Analysis of the laminar forced convection of a nanofluid in a channel with periodic boundary conditions

A steady laminar forced convection in a parallel–plane channel using nanofluids is studied. The flow is assumed to be fully developed, and described through the Hagen–Poiseuille profile. A boundary temperature periodically varying with the longitudinal coordinate in the thermal entrance region is prescribed. A study of the thermal behaviour of the nanofluid is performed by solving numerically the fully elliptic coupled equations. The numerical solution is obtained by a Galerkin finite element method implemented through the software package Comsol Multiphysics (ã Comsol, Inc.). The governing equations have been solved separately both for the fully developed region and for the thermal entrance region. The analysis shows non-homogeneities in the nanoparticle concentration distribution, which are wrongly neglected whenever the homogeneous model is employed.