高水头船闸第二分流口自分流体型水力特性研究

Numerical study of hydraulic characteristics of self-diffluence structure in second diversion port of high-head lock

高水头船闸输水水流能量巨大,水力指标高,对输水系统布置和型式提出了更高要求。大藤峡水利枢纽工程船闸最大设计水头40.25 m,输水系统第二分流口拟采用空腔自分流型式,在国内外尚无先例。通过采用三维数值模拟的技术手段对该分流口型式及输水系统整体分流性能进行系统研究,详细分析在各典型充、泄水时刻第二分流口部位的水动力特性,论证在工程实际应用中的可行性。研究结果表明,在合理布置各分支廊道的出水支孔尺寸后,该分流口型式在充、泄水过程中分流效果较好,但在分流口内部存在典型流速、压力分布区域,特别是在泄水工况下分流口大墩头附近存在较大范围三角低流速紊动区域,可能会对分流口结构造成不利影响。研究成果可为全面掌握该分流口型式的水力特性以及进一步改进优化提供技术参考。

The water flow energy of high-head lock is huge, and the hydraulic indexes are quite high, which puts forward higher requirements for the layout and type selection of the filling and emptying system. The maximum design head of Datengxia single-step lock is 40. 25 m. The second diversion port of the filling and emptying system is intended to adopt a self-diffluence structure and there is no precedent at home and abroad. A systematic research on the diversion port and the performance of filling and emptying system is carried out in this study by means of three-dimensional numerical simulation. The hydrodynamic characteristics of the second diversion port at typical charging and discharging time are analyzed in detail. What＆#39;s more, the feasibility of its application in practical engineering is demonstrated. The results show that the diffluence effect is relatively good in the process of charging and discharging through reasonable arrangement of the outlet hole size of each branch corridor. However, the typical flow velocity and pressure distribution area will appear inside the diversion port, especially in the case of discharging. There is a large region of triangular low velocity turbulent flow near the big pier head, which may have an adverse impact on the structure of the diversion port. The research results can provide reliable technical reference for fully understanding the hydraulic characteristics of this type of diversion port and also contribute to its further improvement and optimization.