射流簇底流消能泄水诱发场地振动特性研究

射流簇底流消能具有消能率高、低雾化影响等优点,但流态复杂,易诱发下游场地振动。通过对某大型水电站泄水下游场地振动原型监测,揭示了场地振动响应的随机分布规律、时域数字特征,利用水工模型试验,分析了场地振动频域能量分布特性,探明了振源。结果表明,场地振动过程表现为连续型平稳随机振动并伴有冲击特征;场地振动主频为0.5~3.0Hz,与消力池水流脉动主频基本一致;水流脉动荷载为场地振动的振源,为振动量预测及减振抑振措施提供了参考依据。

Study on Field Vibration Characteristics Induced by Energy Dissipation with Jet Flow Clusters

Energy dissipation by hydraulic jump with jet flow clusters has the advantage of high energy dissipating ratio and low atomization. But its flow pattern is complex and it may easily induce downstream field vibration. With field monitoring of downstream field vibration of a large hydropower station, random distribution characteristics and time-domain amplitude characteristics were revealed. By hydraulic model test, frequency-domain energy characteristics were analyzed and the vibration source was proved. The results show that the vibration process manifests continuous stationary random vibration with impact feature. The main frequency of vibration is between 0.5 Hz-3.0 Hz, which is basically consistent with the flow fluctuation of still basin. Flow fluctuation is the vibration source. So, it provides reference basis for response prediction and suppression measures of vibration.