中文摘要：

洞、渠组合的长距离泄流系统受大变幅水流条件的影响和局部边界约束,沿程流态十分复杂,因此泄流安全的研究十分必要.本文借助水力模拟与理论分析,以某抽水蓄能电站水库的明流泄洪洞、渠系统为例,研究了复杂运用条件的水力学特性.研究发现泄流过程中因边界约束出现的洞内水跃使跃后缓流段过流能力剧减,引发洞内壅塞与明渠局部漫溢,出现水深随流量改变呈驼峰曲线变化的泄流特异性.这一特异性与洞内水跃的发生及当地的流态转换密切相关,表现为无量纲水深与水流Fr的波状函数关系,相应的特征水深则随Fr呈幂函数规律变化.针对洞内水跃引发的洞内壅塞与明渠漫溢等泄流安全问题,基于多目标、多约束条件的水力优化分析,提出了＂抑制洞内水跃强度、控制流量与流态协调性＂的泄流运行原则,并据此对泄流系统进行了体型优化.试验研究表明通过调整泄流系统的纵横剖面,协调各段的泄流能力与流态,控制特殊部位的水流能量关系,可以有效削弱、控制局部边界约束引发的泄流特异性,消除洞内壅塞,满足复杂水流条件下的泄流安全要求.

英文摘要：

Flow regime of the long-distance discharging system combined by the tunnel and channel is extremely complicated under the combined effect of the flow conditions with large amplitude and the boundary constraint. Therefore, the operation safety during this flood discharging process deserves more attention. By means of hydraulic modeling and theory analysis, taking the discharging system combined with the spillway tunnel and the open channel in the reservoir of a pumped storage power station as an example, we investigate the hydraulic characteristics under the complicate operation conditions. We find that the hydraulic jump in tunnel caused by the boundary constraint reduces the discharging ability of the subcritical flow section after jump sharply ,which may cause the tunnel b[ockage and the channel overflow partly. A specificity that the water depth presents a hump curve with the discharge increasing is found during the discharging process. Analysis shows that the specificity is closely associated with the occurrence of the hydraulic jump in tunnel and the local flow regime transformation, and can be presented by the wavy function between the dimensionless water depth and the flow Froude number Ft. However,the correlation of the characteristic water depth and Fr can be expressed in power function. Besides ,for the problems against discharging safety like tunnel blockage and channel overflow,caused by hydraulic jump in tunnel, we also propose the guide line for the similar discharging operation that ＂reducing the strength of the hydraulic jump in tunnel, coordinating the relationship between the flow discharge and the flow regime＂, based on the hydraulic optimization analysis considering multiple objects and constraint conditions. According to this, the body of the discharging system is optimized. Experiments indicate that, by adjusting the longitudinal and cross profile of the discharging system, coordinating the discharging ability and flow regime of each section, and controlling the water energy relationship