Experimental Study on Secondary Flow in Compound Open Channel

In a compound open channel, the interaction between main channel and flood plain flow is the most important problem to be clarified. This interaction affects the resistance to flow and sedimentation on the flood plain.To carry on the research of the interaction, it is necessary to clarify the flow structure in this region. Strong secondary flow near the boundary, which was showed by Sellin and another researchers, is investigated in experimental compound open channels in this paper. In spite of elusiveness of the secondary flow, many attractive photographs are obtained by the refined techniques for flow visualization. Characteristics of the secondary flow and interaction between main channel and flood plain flow are discussed here.