Acta Mechanica Slovaca 2012, 16(2):84-90 | DOI: 10.21496/ams.2012.023

Unsteady Boundary Layer Flow of an Incompressible Micropolar Fluid Over a Porous Stretching Sheer

K. Govardhan^*, S. Renuka, N. Kishan

Department of mathematics, Osmania University, Hyderabad 500007, A.P, India

Aim of the paper is to investigate the unsteady boundary layer flow of an incompressible micropolar fluid over a stretching porous sheet when the sheet is stretched in its own plane. The stretching velocity is assumed to vary linearly with the distance along the sheet. Two equal and opposite forces are impulsively applied along axis so that the sheet is stretched, keeping the origin fixed in a micropolar fluid. The governing non-linear equations and their associated boundary conditions are first cast into dimensionless form by a local non-similarity transformation. The resulting equations are solved numerically using the Adams- predictor corrector method for the whole transient from the initial state to final steady- state flow. Numerical results are obtained and a representative set is displaced graphically to illustrate the influence of the various physical parameters on the velocity profiles, microrotation profiles as well as the Skin friction coefficient for various values of the material parameter K. It is found that there is a smooth transition from the small- time solution to the large- time solution. Results for the local skin friction coefficient are presented in table as well as in graph.

Keywords: Unsteady flow, micro polar fluid, stretching surface, skin friction, porous medium

Received: January 14, 2012; Accepted: March 15, 2012; Published: October 31, 2012  Show citation