低水头坝消力池内倾斜悬栅辅助消能工的优化试验研究OA

Background Stilling basins are commonly used energy dissipation structures in hydraulic engineering,particularly for low-head dams,where they facilitate hydraulic jumps to dissipate energy and ensure smooth flow transition.In certain projects,optimizing flow patterns requires not only high energy dissipation efficiency but also effective control of the maximum water depth within the basin to suppress downstream surges and ensure channel stability.However,due to constraints such as topography and geology,expanding the basin dimensions is often impractical,making auxiliary energy dissipation structures critical for enhancing performance.Objective This study aims to systematically investigate the impact of suspended grid arrangements on energy dissipation efficiency and water surface fluctuation suppression in low-head dam stilling basins.An innovative bidirectional cross-inclined suspended grid configuration was proposed to overcome the limitations of traditional horizontal layouts,which often require multi-layer structures and increase cost and complexity.Methods Physical model tests were conducted based on Froude similarity criteria(geometric scale:1:20).The experimental setup included an overflow dam model with a stilling basin,where suspended grids with rectangular cross-sections were installed.Four inclination angles(15°,25°,35°,and 45°)and three grid spacings(6 cm,9 cm,and 12 cm)were tested under three configurations:horizontal,unidirectional inclined,and bidirectional cross-inclined.A total of 28 test scenarios(including a control group without grids)were evaluated,with each test repeated four times to ensure reliability.Key parameters measured included water level difference(ΔH),energy dissipation rate(η),and flow patterns.Statistical analysis(ANOVA and Tukey HSD tests)was employed to validate the significance of results.Results The bidirectional cross-inclined configuration demonstrated superior performance in reducing water level differences and stabilizing flow patterns.Compared to horizontal and unidirectional inclined layouts,the average reduction in water level difference increased by 45.67%and 48.9%,respectively.The optimal configuration(35° inclination with 6 cm spacing)achieved a breakthrough reduction in water level difference(>75%)and significantly suppressed water surface fluctuations.Statistical analysis confirmed the superiority of the bidirectional inclined design(p<0.001).While all grid configurations marginally improved energy dissipation efficiency(average η increase:0.85%～1.58%),the primary benefit lay in flow stabilization.Conclusion The bidirectional cross-inclined suspended grid arrangement effectively enhances energy dissipation and flow stability in low-head dam stilling basins.The recommended optimal parameters(35° inclination with 6 cm spacing)provide a cost-efficient solution without requiring complex multi-layer structures.This study offers theoretical insights and practical guidelines for optimizing suspended grid designs in hydraulic engineering applications.