Heat and mass transfer analysis of MHD couple stress fluid flow through expanding or contracting porous pipe with cross diffusion effects

This article investigates the effects of an incompressible laminar magnetohydrodynamic flow of couple stress fluid through an expanding or contracting porous pipe with cross diffusion has been considered. It is assumed that the pipe wall expands or contracts uniformly at time dependent rate. The system of governing partial differential equations and with associate boundary conditions are transformed into non-linear coupled system of equations by using suitable similarity transformations and obtained a solution by homotopy analysis method based Mathematica package BVPh2.0. The behaviour of various non-dimensional important parameters on velocity profiles, temperature and concentration distributions and also the rate of heat and mass transfers are studied and exhibited in the form of graphs. We noticed that the temperature of the fluid is enhanced by cross diffusion effects, whereas the concentration of the fluid decreased. In addition, the concentration of the fluid is decreased as Hartmann and inverse Darcy’s parameters increase.