An exact solution to the problem of MHD transient free convection and mass transfer flow of a viscous, incompressible, and electrically conducting fluid past a suddenly started infinite vertical plate taking into account the thermal diffusion as well as the thermal radiation is presented. Assuming the medium to be nonscattered and the fluid to be nongray, emitting–absorbing, and optically thin radiation limit properties, the equations governing the flow and heat and mass transfer are solved by Laplace transform technique. The expressions for the velocity field, the concentration field, the skin friction at the plate in the direction of the flow, and the coefficient of heat transfer and mass transfer from the plate to the fluid have been obtained, and their numerical values for different values of the physical parameters involved in the problem have been demonstrated in graphs and tables, and these are physically interpreted. It is found that the thermal radiation retards the fluid flow whereas the Soret effect accelerates the flow. The viscous drag on the plate is increased under the Soret and magnetic field effects whereas the thermal radiation reduces the skin friction. Further, the rate of heat transfer at the plate increases under thermal radiation effect. Also, in the presence of radiation, the Soret effect results in a steady increase in the mass flux from the fluid to the plate.

In this study, we investigate the heat and mass transfer in MHD convective flow past an infinite plate, through a porous media in presence of radiation, diffusion-thermo effect, and heat sink. A uniform magnetic field is applied transversely in the fluid region. The novelty of the present work is to analyze the diffusion-thermo effect on the flow phenomena in the presence of heat sink and thermal radiation. The governing equations are solved by perturbation technique to get expressions for velocity, temperature, and concentration fields. The influence of various physical quantities on the flow domain is studied graphically and in tabular form. It has been found that when heat flux is generated due to temperature gradient, the fluid velocity increases whereas the fluid temperature falls due to the diffusion-thermo effect. The current results have been compared with the existing results in some cases and it has been found that the findings of the present study are consistent with earlier findings.

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In this paper, a theoretical study of a three‐dimensional mixed convective mass transfer flow past a semi‐infinite vertical plate embedded in a porous medium has been presented. The novelty of the present work is to analyze the influence of periodic permeability on the flow and transport characteristics in the presence of viscous dissipation and chemical reaction. The equations governing the flow, heat, and mass transfer are solved analytically by using asymptotic series expansion method. The variations in fluid velocity, temperature, and concentration fields due to change of various physical parameters are demonstrated graphically, whereas the numerical values of skin friction and the rate of mass transfer at the plate are compiled in tabular form. It is found that fluid velocity is increased for increasing permeability. Further, it is seen that concentration level of the fluid drops due to chemical reaction.

The problem of a hydromagnetic convective flow of an electrically incompressible viscous conducting fluid past a uniformly moving vertical porous plate is investigated analytically, taking into consideration radiation and thermal diffusion effects. A constant suction velocity is applied to the plate. A uniformly strong magnetic field is supposed to be applied normally to the plate and directed into the fluid region. To find a solution to the problem, an asymptotic series expansion method is used. The effects of thermal diffusion, magnetic field, porosity parameter, thermal radiation, and Grashof number are mainly focused on the discussion of the current problem. Increasing Soret number (Sr) hikes the velocity profile and skin friction but declines Sherwood number. Also, it has been found that, when the magnetic parameter (M) increased, the fluid velocity and the concentration profile decreased.The current results show a good deal of agreement with previously published work. The findings of this study could be relevant in a variety of applications, including diffusion processes involving molecular diffusion of species with molar concentration.