Axisymmetric flow and heat transfer over an unsteady stretching sheet in power law fluid

An analysis is presented for the unsteady boundary layer flow and heat transfer of power law fluid model over a radially stretching sheet. A uniform magnetic field is applied perpendicular to the direction of the flow. With the aid of new similarity transformations, the governing time dependent nonlinear boundary layer equations are converted into nonlinear ordinary differential equations. The transformed coupled ordinary differential equations are then solved analytically by homotopy analysis method (HAM) and numerically by shooting method. The influence of different parameters like, power law index n, magnetic parameter M, unsteadiness A, suction/injection S, and generalized Prandtl number Pr on velocity and temperature profiles are presented graphically and discussed. It is found that the velocity and the thermal boundary layer thickness are the decreasing function of unsteadiness parameter. The impact of the local skin friction coefficient and local Nusselt number is presented in tabular form. (C) 2016 Published by Elsevier B.V.