Influence of heat transfer on MHD flow in a pipe with expanding or contracting permeable wall

The present study investigates the effects of heat transfer on MHD laminar viscous flow in a pipe with expanding or contracting permeable wall. The pipe wall expands or contracts uniformly at a time dependent rate. The governing equations are reduced to ordinary differential equations by using a similarity transformation. An analytical approach, namely the homotopy analysis method (HAM) is applied in order to obtain the solutions of the ordinary differential equations. The effects of various emerging parameters on flow variables have been discussed numerically and explained graphically. Further, we find a good agreement between the HAM solutions and solutions already reported in the literature. (C) 2014 Production and hosting by Elsevier B.V. on behalf of Ain Shams University.