Laminar Flow

Flow in which the head loss is proportional to the first power of the velocity. The flow field can be characterized by layers of fluid, one layer not mixing with adjacent ones. The flow is laminar or turbulent depending on the value of the Reynolds number, which is a dimensionless ratio of the inertial forces to the viscous forces. In laminar flow, viscous forces are dominant and the Reynolds number is relatively small. In turbulent flow, the inertial forces are very much greater than the viscous forces and the Reynolds number is large. Laminar flow occurs very infrequently in open channel flow.