The flow between two concentric cylinders is called annular flow. Find velocity distribution in a cross section for hydrodynamically fully develop annular flow with constant thermophysical properties and incompressible flow. The continuity and momentum equations in cylindrical coordinate system for flow with constant thermophysical properties and incompressible flow neglecting body forces are Continuty Eq. v +-+ = 0 ar r Momentum Eq. in flow (x)direction P(V L +u- ar Ra -- ap + ": + dr2 rar. R