三汊河闸立面二维水动力特性及闸门上脉动压力的频谱分析

Two-dimensional Hydrodynamic Characteristics of Vertical Plane and Spectrum Analysis of Fluctuating Pressure for Sanchahe Gate

为分析三汉河闸下游的水动力特性及泄流时脉动压力对闸体振动的影响，采用数值模拟的方法，利用FLUENT流场模拟软件，对河口闸泄流过程进行立面二维模拟计算，分析了闸下游的流场、流态和沿床面的流速分布。并针对泄流时闸门振动问题，对作用在闸门上的压力特性进行脉动压力的频谱分析及脉动强度分析，得出脉动压力的能量分布和脉动强度在闸门上的分布规律。结果表明，下泄水流所产生的强紊动是造成闸门上压力脉动的主要原因，闸门上脉动压力的高能频率段为0～0．05Hz，2．2m以下的脉动压力对闸门起主要作用，闸门的自振频率大于0．05Hz时可有效避免闸门的振动破坏。

To analyze the hydrodynamic characteristics of the downstream of Sanchahe Gate and the influence of fluc- tuating pressure on gate vibration during discharging, the numerical simulation method and the FLUENT software has been used to simulate the discharge process of two dimensional gate. The flow field, flow pattern and distribution of ve- locity along the river bed have been analyzed. Aiming at the problem of gate vibration during discharging, the pressure effect on the gate has been analyzed by spectrum and fluctuation intensity. The results show that strong turbulent fluctua- tion caused by discharging is the main reason to bring about fluctuating pressure of the gate; high-energy frequency seg ment is 0~0.05 Hz, fluctuating pressure below 2.2 m play the main role on the gate; frequency of gate vibration which is greater than 0.05 Hz can effectively avoid the vibration damage of the gate.