中文摘要：

引入转子动力学双平面平衡理论,将多级密封内的分布气流力等效到气缸两个端面上,建立多级密封动力特性系数识别模型。该模型考虑气缸平动和偏摆混合运动情况,并通过共振的方法放大气流力影响,从而提高识别精度。构建密封动力特性试验台,研究进出口压比、转速、偏心、间隙等因素对密封动力特性系数的影响。试验结果表明,8个刚度阻尼系数随着进出口压比增大有明显增大,且垂直和水平方向存在耦合效应。随转速增大,交叉耦合刚度系数和直接阻尼系数随转速变大趋势明显,而直接刚度系数和交叉阻尼系数变化不很明显。偏心状态下的交叉耦合刚度系数比同心状态下变大,而直接阻尼系数则减小,说明转子在偏心状态下比同心状态下更容易失稳。随密封平均间隙变小,8个动力特性系数绝对值增大。

英文摘要：

Dual plane balance theory of rotor dynamics is introduced,the distributed Alford forces in multilevel seals are done to be equivalent on two end planes of cylinder,and an identification model of dynamic coefficients for multilevel seals is set up.The mixed movement of translation and oscillation occurring on cylinder is considered in this model,and cylinder resonance is used to enlarge the influence of Alford force,thus improving the identification accuracy is accordingly enhanced.An experiment rig for seal dynamic characteristics is constructed to research the influences of inlet/outlet pressure ratio,rotating speed,eccentricity and clearance on dynamic coefficients.Results show that eight stiffness damping coefficients increase obviously with the growth of inlet/outlet pressure ratio,and coupling effects exist in vertical and horizontal directions.The cross-coupled stiffness and direct damping coefficients increase with rotating speed,but the direct stiffness and cross damping coefficients have no obvious change.The cross-coupled stiffness coefficient in eccentric state is greater than that in concentric state,but the direct damping coefficient decreases,which means that the seal-rotor system in eccentric state is easier loss of stability than in concentric state.With the decrease of average clearance of seal,the absolute values of eight dynamic coefficients increase.