Experimental investigation of the evolution of secondary motion in a large amplitude meandering flume

The development of secondary motion along open-channel bends strongly affects the bed deformation and the channel plane evolution. Recent experimental results obtained at the apex section of a large amplitude meandering flume have confirmed that besides the main central circulation cell a second counter-rotating cell develops near the free surface of the outer bank. In the light of such results, in this work the attention is devoted to the analysis of the evolution of the observed secondary motion along whole bend. The analysis is conducted on the basis of flow velocity data collected in five transversal sections along half wave-length of the same large amplitude meandering flume.