Study of couple stresses on MHD Poiseuille flow through a porous medium past an accelerated plate^*

In this paper, we discuss an analytical study of the unsteady MHD flow of an incompressible electrically conducting couple stress fluid in the presence of porous medium between two parallel plates when the lower plate is accelerating while the upper plate is at rest, taking into account the pulsation of the pressure gradient effect and under the influence of a uniform magnetic field of strength B₀. The solution to the problem is obtained with the help of the perturbation technique. Analytical expressions are given for the velocity field, the shear stresses on the boundaries and the discharge between the plates and the effects of the various governing parameters entering into the problem are reported graphically to depict the interesting aspects of the solution.