Dynamic property study on directly-driven rotor system for centrifugal compressors

By establishing a finite element model for a specific directly-driven rotor system,the inherent reverse frequency is calculated.With response to the impact of bearings,the inherent system bending properties are analyzed regarding fixed stiffness and rotary-speed-varied rigidity.In addition,the movement stability is analyzed using the logarithmic decay rate.Subject to API617-related standards,two excitation conditions are imposed for imbalanced response calculation.To this end,a comparison between calculation and testing results has been conducted.