The 24th IAHR-APD Congress (24th IAHR-APD Congress)

70 / 2023-12-29 14:36:43

Research on the Influence of pool and point bar on Continuous Bends Flow

pool-point bar; continuous bends; 3D numerical simulation

The morphology of the riverbed formed by concave erosion and convex sedimentation is a typical feature of curved rivers, and the morphology of the riverbed has a significant impact on the flow structure of curved channels. Based on physical model experimental data, this article applies RNG k- ε Model and VOF method for three-dimensional simulation calculation of continuous curved water flow. Comparing the changes in the flow structure of continuous curved channels under the horizontal bed shape and the beach channel bed shape, the results show that the presence of a beach channel increases the longitudinal flow velocity on the convex bank side near the inlet of the curved channel, while the longitudinal flow velocity on the concave bank side decreases. The high velocity area moves faster towards the concave bank side along the curved channel, resulting in a higher longitudinal flow velocity near the concave bank downstream of the curved top and a lower longitudinal flow velocity on the convex bank side; The circulation is limited in deep grooves, and the speed of migration towards the convex bank along the way slows down. The remaining circulation in the upstream bend attenuates more slowly towards the convex bank in the downstream bend, with a longer impact distance and an increase in the intensity of circulation in the downstream bend. The research results contribute to a deeper understanding of the complex water flow structure and evolution trend of natural meandering rivers, providing scientific basis for the management of meandering rivers.