flow characteristics of a sinuous channel with flexible banks

Laboratory experiments have been conducted to investigate flow patterns in a sinuous curvilinear channel with flexible banks. those experiments focused primarily on rectangular or trapezoidal cross sections with rigid banks, whereas comprehensive experiments pertaining to curved cross sections with flexible banks in a sinuous/meandering channel have not been performed. hence, the flow characteristics in a curved sinuous channel with erodible banks are analyzed in this study. the velocity profile does not reflect the typical straight flow logarithmic profile owing to secondary flow. the velocity magnitude at the entry and exit of the bend is greater than that at the apex of the final and next bends, respectively. the magnitude of the depth-averaged velocity in the bend entry region is 40% greater than that in the bend exit section of the sinuous channel. a negative streamwise reynolds shear stress is observed at some locations of the bend, which confirm the presence of helical flow therein. the turbulent intensities and an analysis of the turbulent kinetic energy (tke) reveal that the magnitude of the helical flow at the inner bank is greater than that at the outer bend of the apex. the depth-averaged tke magnitude in the inner band is higher than that at the outer bend in the apex cross section by more than 50%. this finding is opposite to that pertaining to the velocity magnitude, thus indicating that a region with a greater mean velocity does not imply greater fluctuations. higher-order correlations show that the flux and diffusion of streamwise and vertical normal stresses are indicated in both positive and negative signs, thus indicating sediment mobility in the channel.