瞬态流体激励下离心泵转子振动特性研究

Research on Rotor Vibration Characteristics of Centrifugal Pump under Transient Fluid Excitation

以IS型离心泵三维模型为研究对象,采用计算流体动力学方法(CFD)对离心泵进行非定常流场数值模拟,进而得到作用在叶轮上的瞬态流体激振力。同时建立泵转子系统的二维有限元模型,将流体激振力作为外载荷施加在转子动力学模型上,研究了离心泵在不同工况下不平衡质量与所受流体激振力对叶轮处振动特性及其轴心轨迹的影响。通过对不同位置的轴承处特性进行对比,研究轴承处的振动特征。结果表明:叶轮所受流体激振力具有多种频率成分,且激振力随工况的偏移逐渐增大,泵转子系统在不平衡质量力与瞬态流体激振力作用下,叶轮处的振动幅值最大,其次为轴承处。

Taking a 3D model of IS centrifugal pump as the object of study,having CFD used to simulate the unsteady flow field of centrifugal pump was implemented to obtain the transient fluid excitation force which acting on the impeller.In addition,a 2D finite element model of the pump rotor system was established and the fluid excitation force was applied to the rotor as an external load to investigate the influence of unbalanced mass and the fluid excitation force in different operating conditions on vibration characteristics and axis trajectory of the pump;meanwhile,through comparing the characteristics of the bearing at different positions,the bearing’s vibration characteristics were studied.The results show that,the fluid exciting force of the impeller has multiple frequency components and the exciting force increases gradually with the offset of the working condition.Under the action of unbalanced mass force and transient fluid exciting force of the pump rotor system,the vibration amplitude at the impeller becomes the largest,followed by that at the bearing.