3-D Numerical Simulation of Flow Structures in a Sharp Bend of the Lower Yangtze River

The three-dimensional (3-D) flow structures in the Taiziji Waterway of the Lower Yangtze River were simulated by a 3-D numerical model, where the river plan form is a sharp bend and island-braided. The verification results of the 3-D model indicated that the simulated results agree with the measured data. The patterns of 3-D flow structures in this sharp bend with different discharge were analyzed based on the calculated results.The simulated results demostrated that strong 3-D features of flow structures can be found in the sharp bend of Taiziji Waterway, the bottom velocity vectors point to the convex bank while the surface vectors point to the concave bank. The velocity distribution alone the lateral direction in the sharp bend depends mostly on the flow discharge. The discharge ratio of the left branch increases as flow discharge increases.