Copyright © 2009 Stanford Shateyi and Sandile Sydney Motsa. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The unsteady heat, mass, and fluid transfer over a horizontal stretching sheet has been numerically investigated. Using a similarity transformation the governing time-dependent boundary layer equations for the momentum, heat, and mass transfer were reduced to a sets of ordinary differential equations. These set of ordinary differential equations were then solved using the Chebyshev pseudo-spectral collocation method, and a parametric analysis was carried out. The study observed, among other observations that the local Sherwood number increases as the values of the stretching parameter A and the Schmidt number Sc increase. Also the fluid temperature was found to be significantly reduced by increases in the values of the Prandtl number Pr, the unsteadiness parameter A, and the radiation parameter R. The velocity and concentration profiles were found to be reduced by increasing values of the unsteadiness parameter A.