Author(s): Iehisa Nezu; Wolfgang Rodi
Linked Author(s): Iehisa Nezu, Wolfgang Rodi
Keywords: No Keywords
Abstract: Many observations of straight river have revealed the maximum velocity dip below the free surface, the periodic spanwise variations of sediment concentration, the spanwise formation of the low and high speed zones on the free surface and also the longitudinal ridges and troughs on the river bed. All of these phenomena suggested an existence of cellular secondary currents. So, a three-dimensional behaviour of river flow can be envisaged. An investigation of cellular secondary currents is very important in hydraulic engineering, because they might cause three- dimensional variations of flow patters, bed shear stress, sediment transport and bedforms. It is however difficult to measure accurately the secondary currents in water flows by making use of hot-films because their velocity magnitude is only with 5% of the mainstream velocity.
Year: 1985