中文摘要：

针对传统频域识别密封动力特性系数方法存在的问题，提出利用转子不平衡实现同频激励，在2组不平衡状态下构建4个独立方程，建立密封动力特性系数识别模型。在密封试验台上研究了转子不平衡、转速、进出口压比等因素对密封动力特性系数的影响。试验结果表明动力特性系数中直接项系数相近，交叉项大小相同，符号相反。随着进出口压比和转速的增大，8个密封动力特性系数都增大，直接刚度项增大幅度较交叉刚度项更为明显，直接阻尼项增大幅度与交叉阻尼项接近。同时发现相对振动大小对动力特性系数影响并不大。对影响动力特性系数识别精度的因素进行了分析，提出了试验转速、不平衡工况的合理选择方法。

英文摘要：

Considering the disadvantage of traditional frequency-domain identification method for rotordynamic coefficients of seals, a method of synchronous frequency excitation using rotor unbalance was proposed. 4 independent equations were built under 2 sets of rotor unbalance conditions. Influences of rotor unbalance, rotating speed, inlet/outlet pressure ratio on dynamic coefficients was tested. Results show that the direct rotordynamic coefficients are nearly equal and with same sign in the directions of vertical and horizontal. The cross-coupled items are nearly equal but with opposite sign. 8 rotordynamic coefficients all increase with increasing of inlet/outlet pressure ratio and rotating speed. The direct stiffness coefficients increase more quickly than the cross-coupled. The increasing trend of direct and cross-coupled damping coefficients is almost same. We also find the dynamic coefficients are little affected by different rotor unbalances. Finally, the paper analyzes the influence factors for the identification accuracy, and proposes the choose method for range of rotating speed and rotor unbalance conditions.