径流式叶轮周期性有限元强度振动数值研究

Numerical Research on the Periodic Finite Element Strength and Vibration of the Radial-flow Impeller

径流式叶轮是向心透平、离心压缩机和离心泵等旋转机械的重要部件,在工作状态下承受着巨大的离心力,其安全可靠性至关重要。以某向心透平叶轮为研究对象,基于周期循环对称叶轮强度振动有限元分析理论,建立了向心透平叶轮周期循环对称数值计算模型,分析获得了其在工作转速状态下的变形、应力、固有频率及振型,计算结果表明:向心透平叶轮的最大等效应力为113MPa,位于叶轮本体内环表面靠近进口处,该值远小于材料的屈服极限,说明叶轮满足强度要求;进一步将计算结果与整圈模型计算结果进行对比,不仅验证了周期循环对称模型计算结果的可靠性,还说明采用周期对称模型对径流式叶轮进行强度和振动分析可以在保证计算精度的前提下极大地提高计算效率。

Radial-flow impeller is the key component of the rotation machinery, such as the radial-inflow turbine, centrifugal compressor and centrifugal pump. Large centrifugal force is applied to the impeller under working condition. The security of the impeller is very important. A realistic radial-inflow turbine impeller is selected as the study object. Based on the periodic cyclic symmetric impeller strength and vibration finite element analysis theory, the periodic cyclic symmetric impeller numerical computation model is established. The deformation, stress, natural frequency and vibration shape of the impeller are obtained under working condition. The results show that the maximum value of the impeller equivalent stress is 113MPa. The position of maximum stress is on the inner circle face of the impeller. The impeller meets the strength requirements for the value of the maximum stress is less than the yield limit of the material. The reliability of the cyclic symmetric model computation results are verified by the comparison between the cyclic symmetric model computation results and that of the whole circle model. On the other hand, the computational efficiency of the radial-flow impeller strength and vibration analysis is improved dramatically by the periodic cyclic symmetric model.