Speaker
Description
The displacement of one wetting fluid by another immiscible fluid, i.e., dewetting, in a confined geometry is an essential process in many engineering practices, including enhanced oil recovery, NAPL removal, and microfluidics. For dewetting in uniform tubes, the fluid-fluid interface loses stability once the dewetting velocity attains a threshold and a liquid film is entrained. In this work, we study this stability transition in complex capillary tubes with an emphasis on the geometry effects. We investigate the interfacial evolution in gradient tubes including expanding and contracting ones using phase-field simulations and lubrication theory. The results suggest that unlike in uniform tubes, the film entrainment could be suppressed due to the expanding geometry even though the capillary number once reaches or go beyond the critical value. We further numerically and experimentally investigate the dewetting processes in a necking tube with a parabolic profile, i.e., contracting first and then expanding. Three dewetting patterns are observed including stable displacement, phase trapping, and pinch-off bubbling, which depends on the capillary number and wall wettability.
| Participation | In-Person |
|---|---|
| Country | Sweden |
| MDPI Energies Student Poster Award | No, do not submit my presenation for the student posters award. |
| Acceptance of the Terms & Conditions | Click here to agree |
