An attempt has been made to study the two-dimensional unsteady, hydromagnetic flow of a viscous incompressible, electrically conducting fluid over a vertical surface immersed in a Darcian porous regime with the effects of viscous dissipation and heat source/ generation in presence of thermal radiation and first order chemical reaction. The Rosseland diffusion flux approximation is employed to simulate radiative heat transfer contribution. The transformed conservation equations are solved by using regular perturbation technique. The velocity and temperature profiles have been observed with the increasing heat source/generation (f). Increasing f clearly serves to decelerate both the profiles. It has been also observed that with increasing positive Eckert number (Ec), i.e., wall cooling leads to increase the flow velocity and temperature boosted in the boundary layer. The study of convection fluid in presence of magnetic field and internal heat generation/ absorption are useful application in different branches of science and technology such as geophysical science, cosmic science, fire engineering, etc.

hydromagnetic flow, Rosseland diffusion flux, viscous dissipation, heat source/generation, chemical reaction, MHD flow.