Resistance Studies on Smooth Open Channels

Experiments were conducted on smooth open channels of different shapes to study the propriety of treating a channel as an equivalent pipe, the use of hydraulic mean radius and the application of pipe resistance laws to channels. The findings indicate that smooth pipe laws cannot be applied to smooth channels without reservations. A new approach has been suggested. The method takes into account the force causing motion, the geometrical parameters of the channel, and fluid properties. It is shown that it is possible to obtain mean velocity values without any need to determine the Darcy-Weisbach friction factor, f, or the mean shear stress along the boundary.