Transient Boundary Layer in Stagnation-Point Flow of a Micropolar Fluid Over a Stretching Sheet

An analysis of the transient two-dimensional stagnation-point flow of a micropolar fluid past a stretching sheet in its own plane has been made in the present paper. The unsteadiness in the flow field has been introduced by the sudden change in the surface velocity. The stretching velocity is assumed to vary linearly with the distance from the stagnation-point. Two equal and opposite forces are applied along the x -axis so that the wall is stretched, keeping the origin fixed in a micropolar fluid. The transformed boundary layer equations are solved numerically for some values of the involved parameters using a very efficient numerical scheme known as Keller-box method. The computations have been carried out from the initial steady-state flow to the final steady-state flow. The velocity and micropolar profiles along with the skin friction coefficient at the sheet are analyzed and discussed in detail. When the surface velocity is suddenly raised or is suddenly reduced, it is found that the skin friction vanishes in a small time interval after the start of the impulsive motion, but it does not imply flow separation.