Abstract:
We investigate the influence of a magnetic field on the single diffusive pressure driven miscible displacement of a low viscous fluid by a high
viscous one in a channel using the streamline upwind Petrov-Galerkin based finite element method. We perform transient numerical simulations of the governing continuity and Navier–Stokes equations with magnetohydrodynamic effects coupled with the convection–diffusion
solute concentration equation. We have assumed concentration-dependent viscosity and neglected the density contrast. Our computational
results are found to match quite well with the other results from the literature. We report that the presence of a magnetic field can suppress
the interface instabilities characterized by intense convective mixing and roll-up phenomena for the classical situation of a less viscous fluid
displacing a more viscous one. We have found various new types of instability patterns with the combined influences of the Hartmann number, Reynolds number, and Schmidt number. We show that the mushroomlike structure at the tip of the leading finger grows in volume with
enhancing magnetic field strength, whereas follows the reverse trend as the Reynolds number is increased. Finally, to examine the effect of
magnetic field on the global stability characteristics, we have performed a dynamic mode decomposition analysis. Our analysis demonstrates
that by effectively maneuvering the dimensionless parameters, the displacement rate can be enhanced, and this is attributed to the acceleration in fluid mixing. Apart from the fundamental importance, we trust that the results obtained from this study may help in improving the
operating efficiency of the modern generation process industries.
