Flow and heat transfer of Powell-Eyring fluid over a shrinking surface in a parallel free stream

The present work extends the recently published paper by Jalil et al. (2013) [12] on the boundary layer flow and heat transfer of Powell-Eyring fluid over a permeable surface in a parallel free stream that is moving out of the origin to the case when the surface is moving into the origin (shrinking surface). The governing boundary layer equations are transformed to self similar nonlinear ordinary differential equations using similarity transformations. Numerical results of the resulting equations are obtained using the function bvp4c from Matlab for different values of the governing parameters. Dual solutions are found for negative values of the moving parameter lambda. A stability analysis has been also performed to show that the first (upper branch) solutions are stable and physically realizable, while the second (lower branch) solutions are not stable and, therefore, not physically possible. We notice that these flow characteristics have not been presented by Jalil et al. (2013) [12]. The results are new and original. (C) 2013 Elsevier Ltd. All rights reserved.