Abstract: This paper.Studies power law no-Newtonian fluid rotative flow. in an annularpipe. The governing equation is nonlinear one, we linearized the governing equationby assuming that partial factor is at state. With Laplace transform we obtain ananalytical solution of the problem In the paper several groups of curves are given.these curves reflect the temporal change law and. spatial distribution of fluid velocity.In addition.we study the effection of power law index on the flow field the resultindicates that when the power law index n < 1. the flow velocity is highly sensitive tothe index. and this fact is importanl in related engineering decisions.

Key words: non-Newtonian power law fluid, annular pipe rotative flow, integral transform, approximate solution