Hydrodynamics of lube oil–water flow through 180° return bends

In the present work, the hydrodynamics of high viscous oil–water flow through return bends have been studied. Two bend geometries (U and rectangular) and three flow directions through the bend (up, down and horizontal flow) are considered. It is noted that the direction of flow of two-phase mixture through the bend has a significant influence on the downstream phase distribution while the bend geometry has a negligible influence on the same. The pressure drop is higher across the rectangular bend as expected and the loss coefficients are independent of flow patterns in all the cases.