Exact solution of Marangoni convection in a binary fluid with throughflow and Soret effect

The onset of Marangoni convection in a non-reactive binary fluid layer in the presence of throughflow and Soret effect is determined. The bottom boundary of the fluid layer is assumed to be either conducting or insulating to temperature and solute concentration perturbations while the top boundary is free and insulating. The linear stability analysis is followed and an exact solution is obtained for the corresponding eigenvalue problem by assuming that stationary convection is exhibited at the neutral state. The contribution from the Soret effect is seen only when the throughflow is weak, but however for a wider range of upward throughflow when the bottom boundary is conducting. The instability gets advanced/delayed when the Soret parameter assumes negative/positive values. The results agree well with the existing results in the literature for some particular cases.