Effect of anisotropies in formation of viscous fingering in lifting plate Hele-Shaw cell
Bharatbhushan S. Kale, Kiran S. Bhole, Chetna Sharma
Abstract
This study presents an experimental investigation of viscous fingering formation under anisotropies in Hele-Shaw cell. The lifting plate Hele-Shaw cell employed in this study comprises of two parallel plates firmly positioned one over another with a minuscule gap filled with high viscous fluid, and a low viscous fluid flows through this gap. Two fluids of different viscosity interact in this cell and instabilities are generated due to the viscosity difference. These instabilities need to be suppressed to get controlled and stabilised patterns. Literatures presented these instabilities and explored the various techniques to stabilise them. In this study, a novel strategy consists of use of anisotropy and protrusion on the lower plate of the cell to suppress instabilities is presented. The holes and protrusions explicitly generate the least resistance to the flow of low viscous fluid (air). This results in control flow and guided path for low viscous fluid (air) penetrating into a high viscous fluid. These methods have given excellent control over the instabilities, and beautifully controlled naturally inspired patterns are obtained. Microfractals present in nature, such as leaf venation, honeycomb pattern, are examined and imitated by the proposed method. Experimental results confirm the acceptability of this control strategy.