Numerical and experimental study on vortex optimization in the forebay of a Sandy River

Abstract

Because the movement of water and sediment is complex, the flow pattern in a forebay can be disordered, which can significantly affect the pumping efficiency of a pump station. Using a pumping station in Ningxia, a multiphase water–sand flow model is built based on field measurements and practical engineering. The vortex flow pattern and the cause of sediment deposition are analyzed by numerical simulations and experiments. Furthermore, 36 rectification measures are proposed to improve the vortex flow pattern and sediment deposition in the forebay. The results show that various rectification measures can correct the flow pattern disorder in the horizontal section of the forebay at different angles. However, the correction effect is not obvious in the slope section. For the first time, a combination plan of adding plates to the back wall of the pumping station is proposed. This strategy not only improves the vortex area of the horizontal section of the forebay but also diverts the vortices of the slope section, reducing the vortex range and the sediment content. At the same time, the flow velocity uniformity of the inlet section of the combined optimal solution increases by 19.22%, and the shear angle decreases by 8.81°. The combination of numerical simulation and experimental analysis demonstrates the accuracy of the combined plan, corrects the flow pattern in the forebay, and reduces the sediment content.