基于LMS Virtual.Lab的多级离心泵数值模态分析

Numerical Modal Analysis of Multistage Centrifugal Pump Based on LMS Virtual.Lab Software

选取一典型的多级离心泵,采用LMS Virtual.Lab软件进行数值模态分析,基于分块Lanczos法提取多级离心泵叶轮和壳体的固有频率及振型。结果表明:叶轮结构可以有效地避免共振现象。但是壳体的1阶固有频率与激励频率相近,且其第4阶固有频率及第7阶固有频率分别与二次及三次谐波频率相近,这可能会导致共振现象的发生。该多级离心泵壳体的主要振动方式是弯曲变形,进出口处以及出口端盖处变形较大,所以在设计时应该考虑增强这几个部分的刚度以优化其振动特性。

A multistage centrifugal pump was chosen, LMS Virtual.Lab software was adopted to perform numerical modalanalysis, the natural frequencies and modes of vibration of the impeller and the shell of the multistage centrifugal pump were extracted based on the block Lanczos method. Result shows that the resonance phenomenon can be avoided effectivelybecause of the impeller structure. The natural frequency of the first modal is close to that of the vibration frequency, the natural frequencies of the fourth modal and the seventh modal are close to the frequencies of the second and third harmonic respectively, this may lead to resonancephenomenon. The main vibration mode of the casing of the multistage centrifugal pump is bending deformation. There is large deformations in the import, export and outlet end cap, so it should be considered to enhance the stiffness of these parts in the design to optimize its vibration characteristics.