龙滩工程底孔弧形闸门的自振特性

建立了龙滩底孔弧形闸门有限元模型,并根据Westergaard公式编制程序在闸门面板上施加流固耦合引起的"附加质量".在模态分析中,计算了闸门在空气和水中不同开度下的自振频率,并分析了闸门自振振型,讨论了"附加质量"对闸门自振特性的影响,为弧形闸门动力特性优化设计提供了参考依据.计算结果表明,龙滩底孔弧形闸门自振频率偏低,前三阶自振频率处于水流主要脉动频率范围内,建议优化支臂结构,提高支臂刚度,以避免在水流脉动下引起闸门强烈振动.

Free vibration characteristics of bottom outlet radial gate for Longtan Project

The free vibration characteristics of bottom outlet radial gate for Longtan Project is studied by three-dimensional finite element analysis.According to Westergaard expressions,the additional mass due to fluid-structure coupling motion is taken into account.The free vibration frequencies of the radial gate in the water as well as in the air at the different gate's openings are calculated.The influences of additional mass on the tainter gate are discussed so as to provide scientific basis for the dynamic optimization design of the gate.The study shows that the free vibration frequencies of the radial gate in the water are on the low side;the first three are exactly between the dominant frequencies of water flow.It is suggested that the support arm should be optimized so as to improve its rigidity to avoid the intense vibration of gate.