Experimental Investigation of the Growth of Mixing Zone in Miscible Viscous Fingering

An experimental study is performed to study the growth of the mixing zone in miscible viscous fingering. Rectilinear flow displacement experiments are performed in a Hele-Shaw cell over a wide range of viscosity ratios (1 to 700) by injecting water into Glycerol solutions at different flow rates. A linear growth in mixing zone is observed in all the experiments. The mixing zone velocity increases with the viscosity ratio up to viscosity ratios of 330 and the trend is consistent with Koval's model (Koval 1963). However, at higher viscosity ratios the mixing velocity plateaus signifying no further effect of viscosity contrast on the growth of mixing zone.