Study of Secondary Flow and Sediment Transport in a Laboratory-scale Model of a Meandering River

抄録

Secondary currents strongly influence shapes of meandering rivers and cause sediment deposition on the inner banks and erosion on the outer banks. We report the curved channel measurements on secondary flow effects on flow pattern and on bed formation. The laboratory experiments were performed with a steady discharge until an equilibrium conditions was reached. A physical hydraulic model of the Sai Gon river portion around Thanh Da peninsula in Ho Chi Minh City was built respectively at scales of 1:500 and 1:100 in the horizontal and vertical directions. Both streamwise velocity and transverse velocity were obtained using three-dimensional Acoustic Doppler Velocimeter while sediment transport rates were evaluated by a sand trap. Our laboratory investigation provided evidence of secondary flow development in terms of position and magnitude and the relation to the bed morphology of the studied river. These results emphasize the crucial role of secondary flow in river dynamics and can be attributed to the numerical simulation process.