This paper investigates the effects of radiation and chemical reaction on the unsteady MHD oscillatory flow of viscous, incompressible, electrically conducting, optically thin fluid in a channel filled with saturated porous medium in the presence of an aligned magnetic field. The closed form of analytical solutions are obtained for velocity, temperature and concentration fields using perturbation technique in two cases of boundary conditions, namely, (1) when the plate is at constant temperature with constant concentration levels (2) when the plate is at constant heat and mass flux. Skin-friction in terms of shear stress (t), rate of heat transfer in terms of Nusselt number (Nu) and the rate of mass transfer in terms of Sherwood number (Sh) are derived. The behavior of various flow quantities such as Grashof number for heat transfer (Gr), Grashof number for mass transfer (Gm), magnetic Reynolds number (Rm), Reynolds number (Re), Peclet number (Pe), chemical reaction rate constant (Kr), radiation parameter (N), magnetic parameter (M), porosity parameter (S), frequency of the oscillation (w), a constant (l) and an angle (f) on the velocity, temperature, concentration, skin-friction coefficient and the rate of heat and mass transfer are discussed and analyzed through graphs and tables for both cases of the study. It has been found that, velocity and skin-friction increase for an increase in the thermal Grashof number and decrease for an increase in the magnetic field parameter or porosity parameter or angle f.

oscillatory flow, porous medium, heat and mass transfer, magnetic field.