竖井消能工折板压强及脉动特性分析*

为研究泄流过程中折板式竖井消能工水动力荷载作用，以某深隧排水工程竖井为研究对象，开展正态水力模型试验，研究恒定流与非恒定流条件下折板压强分布规律及脉动特性，分析折板间距和倾角对频谱特征影响。结果表明:上层折板承受时均压强为中层和下层折板1.5~3倍；恒定流条件下折板瞬时压强脉动幅值随入流量和折板间距增大而增大，随折板倾角增大而减小，功率谱密度优势频段为0~2.5 Hz；非恒定流条件下折板瞬时压强自上而下依次减小，功率谱密度优势频段介于0~4.0 Hz。研究结果可为竖井折板结构防振设计提供参考。

Analysis of baffle-drop pressure and fluctuation characteristics of shaft energy dissipator

In order to study the hydrodynamic load effect of baffle-drop shaft energy dissipator during the discharge process,taking the shaft of a deep tunnel drainage engineering as the research object,the hydraulic model tests were conducted to investigate the distribution laws and fluctuation characteristics of baffle-drop pressure under the steady flow and unsteady flow conditions,and the influence of baffle-drop spacing and angle on the spectrum characteristics was analyzed.The results showed that the time-average pressure of the upper baffle-drop was 1.5~3 times that of the middle and lower baffle-drops.The fluctuation amplitude of instantaneous pressure under the steady flow condition increased with the increase of inflow rate and baffle-drop spacing,while decreased with the increase of baffle-drop angle,and the dominant frequency band of the power spectral density concentrated at 0~2.5 Hz.The instantaneous pressure of baffle-drop under the unsteady flow condition decreased from top to bottom,and the dominant frequency band of the power spectral density was 0~4.0 Hz.The research results can provide reference for the anti-vibration design of baffle-drop structure in the shaft.