ANALYTICAL AND LEVEL-SET METHOD-BASED NUMERICAL STUDY FOR TWO-PHASE STRATIFIED FLOW IN A PLANE CHANNEL AND A SQUARE DUCT

The present work involves detailed nondimensional study of density-matched viscosity-stratified flow at various viscosity ratio (eta) and Reynolds number. For fully-developed flow with increasing eta, it is found that the maximum U-velocity (U-max), and pressure gradient increases whereas interface height decreases monotonically. For developing flow, it is shown that the U-max increases whereas the interface height decreases asymptotically along the axial direction. However, the increase and decrease is more for square duct as compared to the plane channel. Furthermore, a set of development-length correlations are proposed for the plane channel. The present results can be used for the efficient transportation of a more viscous fluid.