Homotopy analysis of unsteady boundary layer flow adjacent to permeable stretching surface in a porous medium

This communication deals with the unsteady boundary layer flow of a viscous fluid in porous medium started due to the impulsively stretching of the plane wall. The wall is assumed to be porous so that suction or injection is possible. Complete analytic solution which is uniformly valid for all the dimensionless times 0 ⩽ τ < 0 in the whole spatial region 0 ⩽ η < ∞ is obtained by a purely analytic technique, namely the homotopy analysis method. Results are discussed through graphs.