锥形间隙孔型阻尼密封动力特性分析及抑振机理

应用非定常动网格技术建立了锥形间隙孔型阻尼密封动力特性多频椭圆涡动求解模型，研究了锥形度和涡动频率对孔型阻尼密封泄漏特性与动力特性的影响，分析了锥形间隙孔型阻尼密封的抑振机理。结果表明:锥形间隙增强了孔型阻尼密封的泄漏直通效应，增加了密封泄漏量。在平均间隙相等的情况下，收敛间隙孔型阻尼密封泄漏量小于发散间隙孔型阻尼密封；在同一涡动频率下，刚度系数随着锥形度的增加而增大，阻尼系数随着锥形度的增加而减小；收敛间隙孔型阻尼密封具有较大的正直接刚度，增加了转子系统的固有频率，发散间隙孔型阻尼密封产生较大的负直接刚度；收敛间隙孔型阻尼密封具有较大的有效刚度和穿越频率，较小的有效阻尼，发散间隙孔型阻尼密封具有较大的有效阻尼，较小的有效刚度和穿越频率；在锥形间隙孔型阻尼密封结构设计时，需要同时考虑转子系统固有频率和同心度的影响。 

Rotordynamic characteristics analysis and suppression vibration mechanism of taper clearance hole-pattern damper seal

A solution model of the rotor dynamic characteristics for taper clearance hole-pattern damper seal using unsteady transient solution combined with mesh deformation technique was established. The influences of taper degrees and whirling frequencies on the leakage rates, rotor dynamic characteristics, and suppression vibration mechanism of taper hole-pattern damper seal were studied. Results showed that, the leakage straight-through effect of the hole-pattern damper seals was enhanced by taper clearance, which increased the leakage rates. The leakage rates of convergent-clearance hole-pattern damper seals were less than the divergent-clearance hole-pattern damper seals when there was the same average seal clearance. The stiffness coefficients increased with the increase of taper degrees, while there was an opposite trend for the damping coefficients under the same whirling frequency of the rotor. The convergent-taper hole-pattern damper seals had large posi tive direct stiffness, and increased the natural frequency of rotor system, while divergent-taper hole-pattern damping seals had large negative direct stiffness. The convergent-taper hole-pattern damping seals had large effective stiffness and cross-over frequency, and small effective damping. The divergent-taper hole-pattern damper seals had large effective damping, small efective stiffness and cross-over frequency. The concentricity and the natural frequency of rotor system should be considered when design of taper clearance hole-pattern damper seals.