Steam flow excited vibration and dynamic characteristics of seal in different rotor whirling motion

Abstract A multi-frequency conical whirl model was established to investigate the influence of different rotor whirling motion on seal steam flow excited vibration and dynamic characteristics. The simulation method of rotor motion was improved to adapt the ultra-supercritical steam turbine, in which the whirling motion and rotational motion were decomposed by user-defined function (UDF). The seal steam flow excited vibration and dynamic characteristics of parallel whirl motion, semi and full conical whirl motion were present. The influences of different rotor motion were analyzed via pressure waveform. The dynamic coefficients have the obvious variation in semi and full conical whirl motion. The expansion profile of seal cavity caused by conical whirl motion makes the fluctuation range of circumferential pressure great.