Flow Pattern Analysis and Rectification Measures of Box Culvert in Urban Rainwater Pumping Station with Oblique Pipe Culvert

Abstract

 In order to study the influence of oblique pipe culvert inflow on hydraulic flow characteristics of urban rainwater pumping station and explore effective rectification measures to improve bad flow pattern, based on computational fluid dynamics (CFD) method, box culvert flow pattern analysis and rectification measures research of oblique pipe culvert inflow urban rainwater pumping station are carried out. According to the bad inlet flow state, by designing and arranging 3  different rectification measures in the gate shaft, the improvement effect of each rectification measure on the inlet flow state and water distribution uniformity of the box culvert is analyzed and compared, and the best scheme is selected and verified by physical model tests. The research shows that the oblique pipe culvert inflow is easy to cause uneven flow distribution in each hole of the box culvert and adverse flow patterns such as deflection flow, backflow, vortex and the like, thus deteriorating the inflow state of the forebay and affecting the safe operation of the pumping station;  The combined rectification measures of diversion piers, composite beams and short diversion piers arranged at the back can significantly improve the bad flow pattern at the gate shaft, box culvert and forebay inlet, and effectively improve the uniformity of flow distribution in each hole of the box culvert, wherein the imbalance of flow distribution in each hole of the box culvert is reduced to between ±0.03  and the uniformity of total flow distribution in the box culvert is improved to 0.905。" The research results of this paper can provide useful reference for the design of rainwater pumping stations in the same type of cities.