复杂环境条件下,水利工程泄洪建筑物会出现正向和侧向进水并存的复合式进水工况,导致其进水口方向与河流主流方向不一致,进水口前产生的漩涡特性复杂,使得常规消涡措施效果并不理想。针对复合式进水工况下泄洪洞存在的漩涡问题,依托某抽水蓄能电站开展模型试验研究,分析漩涡产生原因并提出消涡思路,设计消涡措施。结果表明:在水流进口侧,缩短消涡梁间距可有效截断漩涡增大路线;同时,在布置3根消涡梁基础上,增设3块贴合进口形状的30°三角消涡板,并延长中间消涡竖梁宽度的方法可增加消涡能力。该方法可将直径7.5 cm的吸气漩涡彻底消减为直径0.1~0.3 cm的表面漩涡,达到完全消除复合式进水工况下吸气漩涡的目标。研究成果可为类似进水口的消涡设计提供有效参考。

[Objective] In hydraulic projects, flood-discharge structures operating under compound water inlet conditions often exhibit complex vertical-axis vortices at the inlet in which the approach flow direction differs from the mainstream river direction. Traditional vortex elimination measures perform poorly under such conditions, and severe air-entraining vortices may threaten structural safety and operational efficiency. Based on a pumped-storage power station, this study aims to clarify vortex mechanisms through physical modelling and to develop an efficient and economical vortex elimination measure that completely suppresses air-entraining vortices, thereby providing design guidance for similar projects. [Methods] A 1∶50 undistorted clear-water physical model was built under Froude similarity to ensure geometric, kinematic, and dynamic similitude. Several operating conditions (check, design, energy dissipation, and scour protection) were simulated to reproduce actual operation. Vortex characteristics were observed (air-entraining vortices up to 7.5 cm diameter) without any suppression measures. Five vortex elimination schemes were then tested: Scheme 1—conventional vertical vortex elimination beams with an optimized inlet; Schemes 2-4 —addition of 30° triangular vortex elimination plates to the beams, adjusting beam spacing and width, and reducing the inlet angle α; Scheme 5—a comprehensive optimization scheme using monolithic concrete to simplify the structure. Digital imaging and thin-walled triangular weirs were used to quantitatively analyze vortex elimination effect and flow improvement of each scheme. [Results] (1) Cause of vortices: superposition of lateral and longitudinal inflows under compound conditions markedly increased initial circulation, generating strong vortices within 30° of the inlet (100% type-F vortices at stage 3).(2) Comparison of vortex elimination performance: conventional beams (Scheme 1) merely downgraded type-F to type-D vortices without eliminating air entrainment. Adding 30° vortex elimination plates and optimizing beam spacing (Schemes 2-4) reduced vortex diameter from 7.5 cm to 0.1-0.3 cm, leaving only minor concave vortices (type B) at stage 3. Scheme 5 (preferred) completely eliminated air-entraining vortices while simplifying construction and maintaining smooth flow under all operating conditions. (3) Innovations: 30° triangular vortex elimination plates conformed to the inlet geometry, reducing the inflow angle α and suppressing initial circulation. Widening the central vertical beam enhanced vortex interception and disrupted vortex structure. Scheme 5 replaced complex components with a monolithic concrete pour, balancing effectiveness and constructability. [Conclusions] Vortex intensity under compound water inlet conditions is directly linked to the inlet angle α and initial circulation. Lateral flow amplifies complexity and hazards. Combining vortex elimination beams with 30° triangular vortex elimination plates completely eliminates air-entraining vortices, reducing vortex size by over 98% and remaining effective under all operating conditions. The optimized Scheme 5 balances vortex elimination performance with economy and offers a transferable design paradigm. The findings overcome the limitations of traditional vortex elimination measures and provide valuable guidance for high-head, multi-directional hydraulic projects.