三峡永久船闸输水廊道第一分流口体形研究

Optimization of the first diversion port in the conduit system of Three Gorges Ship Lock

抽水调试期间的原型观测表明,三峡永久船闸输水廊道第一分流口附近存在较强的空化噪声;抽干检查发现,第一分流口的隔板上发生了轻微空蚀破坏。本文根据原型观测结果,采用三维紊流模型成功地反演了第一分流口周围的流速场和压强场,研究表明第一分流口隔板体形是引起空化空蚀的主要原因。文中模拟了8种分流口隔板体形对周围流场的影响,分析表明,减免空蚀的切实可行的工程措施是将第一分流口隔板进口体形由圆弧面改为椭圆曲面,椭圆曲面的长、短轴之比建议取2.25。

The prototype observation during the test of Three Gorges Ship Lock shows that there is strong cavitation near the first diversion port of the conduit system. After the test, the inspection shows that there is slight cavitation damage on the division plate of the first diversion port. The turbulent flow field near the first diversion port is successfully simulated by means of the standard k-ε model and the calculated initial conditions are based on the prototype observatiohs. It is shown that the shape of the division plate of the first diversion port causes the cavitation. For avoiding cavitation, the best way is to modify the structure of the first diversion port. The influence of 8 kinds of division plates on the circular turbulent flow field is simulated. The optimized structure of the division plate is recommended, that is the head form of the division plate changed from semi-cireular to semi-elliptic, and the length ratio of the major axis to the minor axis is recommended to be 2.25.