基于流固耦合的卧式轴流泵叶轮模态分析

研究轴流泵转轮的振动特性,对于避免轴流泵工作时发生共振、保证水泵安全稳定运行有重要意义。运用有限元软件ANSYS Workbench,结合流固耦合方法,分析某泵站卧式轴流泵的模态,计算轴流泵叶轮转子在空气和水中的各阶固有频率及其振型,并分析了叶轮固有频率的变化规律及其原因。结果表明,水介质会引起叶轮各阶固有频率的降低,各阶固有频率降低系数的范围为0.10~0.38,降低系数大小与各阶振型有关,水中振型和空气中的振型相似,振幅有所减小,水体的附加振动质量是引起叶轮各阶自振频率降低的原因。

Modal Analysis of Horizontal-axial-flow Pump Impeller Based on Fluid Solid Coupling

It is important to analyze the vibration characteristics of the axial-flow pump impeller for avoiding resonance and ensuring the safe and stable operation of the pump. A modal analysis has been conducted on a horizontal-axial-flow pump in a certain pump station using the finite element software ANSYS Workbench combined with fluid solid coupling method. And then the natural frequencies and mode shapes of the impeller in air and water were calculated, respectively. Finally, the laws and the reasons that cause natural frequency changes have been analyzed. The results show that the fluid will lead to decrease of natural frequencies of the impeller, and the reduction coefficients is in the range of 0.1 and 0.38; the value of reduction coefficients is related to the corresponding mode shapes; the vibration modes in air and in water is similar, and the vibration amplitude is lower than that in air; the fluid added mass effect is the reason that cause the natural frequency reduction in water.