Improving the flow pattern in the inlet forebay with diffusion angle in the Xuliu Irrigation Station

Abstract

【Objective】 The inlet forebay with a diffusion angle is a component of pump stations that helps distribute water flow evenly before it reaches the pump. We present a method in this paper to optimize the design of the inlet forebay, using the Xuliu Irrigation Station as a case study. 【Method】 The proposed method utilized the Navier-Stokes equations and the RNG k-ε turbulence model. Three-dimensional water flow in the forebay was numerically simulated under various scenarios, including the current configuration, modifications to the guide walls, and the addition of support columns. The optimal forebay design was determined by comparing the flow patterns generated in each scenario. 【Result】 Both guide walls and support columns improve flow patterns. Installing support columns increases the uniformity of average axial flow velocity distribution and the velocity-weighted average angle at the channel outlet to 97.74% and 88.42°, respectively, slightly surpassing the performance of the guide wall scheme and improving by 1.14% and 1.25° over the current configuration. At the channel inlet, the uniformity of average axial flow velocity distribution and velocity-weighted average angle were 62.86% and 65.82°, respectively, which were significantly higher than those achieved with the guide wall scheme and represented increases of 26.4% and 36.9° over the current configuration. The support column scheme also reduced the proportion of the vortex area in the forebay to 5%, compared to 7% with the guide wall scheme and 45% with the current configuration. 【Conclusion】 Installing support columns effectively improves the uniformity of water flow diffusion and reduces vortex areas, enhancing flow patterns in the forebay compared to the guide wall scheme. These results provide guidance for renovating the forebay at the Xuliu Irrigation Station and similar irrigation projects.

Keywords

• xuliu irrigation station
• forebay
• large diffusion angle
• flow pattern
• rectification measures
• numerical simulation