Executive Summary : | The study aims to investigate the global stability of single and stratified two-phase flow in a rectangular duct with a soft, deformable wall. Previous studies have shown that the presence of a soft wall can induce new instabilities or inhibit existing ones. The infinite parallel plate assumption reduces complexity by assuming that the basic state depends on cross-flow spatial coordinates. However, real flows occur in rectangular/square ducts, where the basic state depends on two spatial coordinates (cross-flow and span-wise directions). The parallel flow approximation reduces complexity but may not accurately capture the behavior of real systems, as confinement leads to flow stabilization. The presence of a soft wall could induce a destabilizing/stabilizing mechanism. The study aims to systematically evaluate the stability boundaries for single and two-liquid flow in a rectangular duct. The results could be useful in enhancing mixing efficiencies in microfluidic devices made of soft elastomers by tuning the elastic modulus of the soft wall. For two-fluid flow cases, the results could offer insight into controlling different flow regimes using wall compliance. |