Flow-Establishment Length in Rectangular Channels and Ducts

Laboratory experiments related to open channel hydraulics are generally intended to be carried out in the fully developed flow region of a rectangular flume. The developing region, in channels as well as in ducts, is a complex three-dimensional flow region influenced by secondary circulation and free surface effects, and is therefore not amenable to analytical solution. Laboratory data and a numerical model have been used to study the variation of the length of flow establishment in rectangular channels.