Abstract:
We perform linear stability analyses and direct numerical simulations to investigate
the influence of the dynamic viscosity on viscous fingering instability in miscible slices. Selecting
the characteristic scales appropriately, the importance of the magnitude of the dynamic viscosity
of individual fluids on viscous fingering in miscible slice has been shown in the context of the
transient interfacial tension. Further, we have confirmed this result for immiscible fluids and
shown the similarities between viscous fingering in immiscible and miscible slices with transient
interfacial tension. In a more general setting, the findings of this letter will be very useful for
different viscous flows, such as displacement of a buoyant miscible layers in a vertical Hele-Shaw
cell, viscous fingering instability with viscosity-dependent dispersion, etc.
