An experimental identification model of rotordynamic coefficients of seals using unbalanced synchronous excitation method

作者：Cao, Hao^*; Yang, Jiangang; Zhang, Wanfu; Guo, Rui

来源：Journal of Mechanical Science and Technology, 2013, 27(7): 1885-1892.

DOI：10.1007/s12206-013-0504-1

• Vibration
• Rotordynamic coefficients
• Seals
• Experimental identification

This study presents an improved impedance method based on unbalanced synchronous excitation to identify the rotordynamic coefficients of labyrinth seals. The rotordynamic coefficient test is implemented near the cylinder resonance frequency to enlarge the influence of seal force. The force generated by the rotor unbalance is used to provide synchronous frequency excitation for the rotordynamic coefficient test. Four unique equations are set up under two sets of different rotor unbalance conditions to obtain four unknown complex rotordynamic coefficients. The factors that influence the rotordynamic coefficients of seals, namely, unbalance mass, inlet/outlet pressure ratio, and rotating speed, are considered. The dynamic coefficients are minimally affected by different rotor unbalances. The direct items are nearly equal with same signs, whereas the cross-coupled items are nearly equal with opposite signs. All coefficients increase with increasing inlet/outlet pressure ratio and rotating speed. The direct stiffness coefficients increase more quickly than the cross-coupled items. In addition, the effect stiffness and effect damping coefficients are analyzed; results indicate that both coefficients increase with increasing rotating speed.

• 出版日期2013-7
• 单位东南大学