An analytical solution for boundary layer flow of a nanofluid past a stretching sheet

In this paper, the problem of boundary layer flow of a nanofluid past a stretching sheet has been investigated analytically by using the Homotopy Analysis Method. Both the effects of Brownian motion and thermophoresis are considered simultaneously. An analytical solution is presented which depends on the Prandtl number Pr, Lewis number Le, Brownian motion number Nb and thermophoresis number Nt. The results show that the reduced Nusselt number is a decreasing function of each dimensionless number, while the reduced Sherwood number is an increasing function of higher Pr and a decreasing function of lower Pr number for each Le, Nb and Nt numbers like the results presented by Khan and Pop. Contrary the results presented by Khan and Pop, It is found that the reduced Nusselt number decreases with the increase in Pr for many Nb numbers. However for a special Nb, there are conversely interesting results that are clearly discussed in this paper. (C) 2011 Elsevier Masson SAS. All rights reserved.