巴塘水电站导流洞平面闸门流激振动试验研究

针对巴塘水电站导流洞动水闭门过程中门体出现振动的问题,根据水弹性和重力相似准则建立比尺为1∶25的物理模型。通过模型试验,对平面闸门在闭门阶段的振动加速度、持住力以及门体应变等参量进行试验测定。试验结果表明:闸门在局开挡水时,水平向最大单倍位移幅值为91.974μm,振动危害较小;结构最大Mises应力值为11.32 MPa,闸门整体应力满足强度要求,平面闸门安全可靠。通过ANSYS Workbench平台对闸门进行模态分析。结果表明:干模态基频为40.05 Hz,湿模态基频为35.40 Hz,闸门挡水时脉动主频在10 Hz以内,与湿模态第1阶频率相差较大,闸门产生共振的可能性较低。本文采取的水弹性模型试验技术能够较好地反映平面闸门的动力特性,能够较为准确地预测和分析闸门的流激振动响应特性,可为类似工程的结构优化设计及运行安全监测提供参考。

Experiments on flow-induced vibration of the plain gate in the diversion tunnel of Batang Hydropower Station

Aiming at the vibration problem of the gate body during hydrodynamic closing of the diversion tunnel in Batang Hydropower Station,a physical model with a scale of 1∶25 was established according to the criteria of hydro-elasticity and gravity similarity.The vibration acceleration,holding force and strain of the plain gate in the closing phase were measured in the model test.The results show that the maximum horizontal single-fold displacement amplitude is 91.974μm,with which the gate vibration is unlikely to happen.The maximum Mises value of the structure is 11.32 MPa,the overall stress of the gate meets the strength requirements,and the plain gate is safe and reliable.Then a modal analysis of the plain gate was carried out using ANSYS Workbench.The analysis results show that the dry mode fundamental frequency is 40.05 Hz,the wet mode fundamental frequency is 35.40 Hz,and the main pulsation frequency is within 10 Hz when the gate is retaining water,which is significantly different from the wet mode order 1 frequency,so the possibility of gate resonance is low.The hydrodynamic model test adopted in this paper is suitable for the simulation of the dynamic characteristics of plain gates,it can predict and analyze the gate response to flow-induced vibration accurately.This research can provide some reference for the structural optimization design and operation safety monitoring of plain gates in similar projects.