Effects of Constant and Time-Dependent Extraction Flow Rates in a Radially Convergent Hele-Shaw Fingering Flow

Fluid displacement plays an important role in many industrial applications. Examples includeenhanced oil recovery (EOR), carbon capture and storage (CCS), biological filtration and the gasdiffusion layers of fuel cells. When a less viscous fluid (air) displaces a more viscous fluid (water),the interface between the two fluids evolves into ramified fingering patterns. Because the interfacefingering significantly decreases the displacement efficiency, understanding the fingeringmechanism and developing methods to control/suppress the interface instability cannot beoveremphasized. Recent literature shows time-dependent injection rates may suppress viscusfingering in the radial divergent Hele-Shaw flows. Theoretically, time-dependent extraction rateswould also work in the radial convergent Hele-Shaw flows; however, there has been no successfulreport of fingering suppression using time-dependent extraction rates. We speculate the combinedeffects of wettability with extracted interface velocity may be responsible for the failure. Thisproject will conduct careful experiments and computation to study the combined effects ofwettability and extraction. The project contains two parts. The first part is to experimentally clarifythe combined effects of wettability with extracted interface velocity by measuring the effective fluidthickness in the radially convergent and divergent flow, respectively. The second part is to developthe computation model to study the details of spatial and temporal behaviors of the flow, such asvelocity and pressure gradient, and to perform parametric optimization. All the work will be done in2 years. The results will improve the fingering control and benefit the technology of fluiddisplacements.