泄洪洞工作闸室及陡坡明渠段体型优化数值模拟

对九甸峡水电站右岸泄洪洞工作闸室,包括圆直段、圆变方段、方洞段、弧形闸门段、渐变段和明渠段流场进行了数值模拟。获得了水面线、压力、空化数、流速等水力要素。成功捕捉到了压力洞出口处的水翅、突扩跌坎处侧空腔和底空腔。计算结果与实测数据符合较好,根据计算结果,提出了能解决原方案负压区严重和明渠陡坡空蚀破坏问题的泄洪洞体型修改方案。     

窄缝挑坎水翅轨迹及降雨特性研究

窄缝挑坎因边墙收缩形成的水翅击打岸坡,可能会对岸坡稳定构成威胁,而相关研究鲜见报道。为了揭示该消能工水翅运动规律及其形成的降雨强度在下游临岸侧的分布特性,通过建立系列物理模型,开展了窄缝挑坎收缩比和挑角与水翅特性间关系研究。结果表明:随着收缩比减小,水翅被抛射得越高,次生水翅引起的降雨分布区域位置上移、范围增大;随着挑角减小,水翅顺水流向运动轨迹变化不大,但横向扩散加剧导致降雨横向分布范围增大。在此基础上提出了次生水翅横向扩散系数的概念,可用于预测不同挑坎体型下次生水翅引起下游降雨范围的形状特征。该成果可丰富窄缝挑坎研究内容,扩大研究范围,并为其体型设计提供更全面的理论依据。     

Hydraulic characteristics of water-wings for the middle-pier of a discharge tunnel

1. INTRODUCTION In the design of a discharge tunnel with high water head and large flow, it is important to study the cavitation and the energy dissipation, such as the prevention of cavitation for slots of various gates [1-4], the effects of entrained ai…     

EXPERIMENTAL STUDY ON CAVITATION AND WATER-WING FOR MIDDLE-PIERS OF DISCHARGE TUNNELS

1. INTRODUCTION Discharge tunnel ,specially , deep-water one , is a sort of usual flood discharge structure with pressure flows in the inlet section,followed pres- sure flows or free flows ,and is used in flood dis- charge or emptying a reservoir , and/or washing sands .For deep-water tunnels ,the designs were u- sually adopted of the manners of the shaft ,of the inclined sectionin the inlet or in the outlet ,called visually as “Dragon up one’s head”or “Dragon down one’s tail”in Chi…     

Hydraulic characteristics of bottom underlay-type pier for water-wing control

The pier, placed at the outlet of the pressure flow section, is an effective design to deal with the problems of the manufacture and operation of the gates fbr a discharge tunnel with high water head. It is crucial to control the water-wing, induced by this type of the pier. Through observing the phenomena of the water-wing, the reason of the water-wing inception, i.e., the concave of the flow surface, was presented, and a type of the new pier with bottom underlay was designed. The hydraulic characteristics of the pier, including the variations of the water-wing features, both length and height, with the water head, as well as with the concave depth, and with the height of the bottom underlay, and the variations of the concave depth with the height of the bottom underlay, were investigated by physical model experiments. The results show that the approach of the modification of the concave through the structures with the bottom underlay-type pier is remarkably effective in the water-wing control.