화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.9, 4119-4133, 2020
Multiphase Viscoplastic Flows in a Nonuniform Hele-Shaw Cell: A Fluidic Device to Control Interfacial Patterns
Inspired by the problem of the removal of in situ gel-like materials via a displacement flow process, we use a fluidic device known as Hele-Shaw cell to study the flow parameters related to the displacement flow efficiency. In a displacement flow process, when a less viscous fluid displaces a more viscous fluid, exotic interfacial patterns known as viscous fingering appear. Motivated by the recent developments in the literature, we experimentally study the effects of a simple cell nonuniformity with various gap gradients in the flow passage on the viscous fingering problem in the displacement of a viscoplastic gel (Carbopol) by air. We show that a linearly converging/diverging cell can be used to control certain interfacial patterns and improve the displacement efficiency. We classify the flow regimes into smooth finer and rough finger patterns, using the average capillary number ((C) over bara) and the average Bingham number ((B) over barn) or their combinations.