基于系统响应特征的指尖密封泄漏特性分析

结合指尖密封动态工作特点,通过研究转速和转子不平衡力与转子跳动之间的关联规律,得到转子的位移激励,构建了指尖密封系统的动态计算模型,依据指尖密封的系统响应特征研究其泄漏间隙的获取办法,进而基于泄漏间隙特征建立了指尖密封动态泄漏量计算方法.针对某型发动机转子进行了动态泄漏量分析,结果表明:在转子每个转动周期内,指尖密封的动态响应跟随转子激励周期性变化,由此产生的动态迟滞泄漏间隙也随时间而周期性变化,迟滞泄漏的大小随着密封上下游压差的增加而增大,随着转子转速的升高先增加后减小；设置一定的装配过盈量能够一定程度地减小迟滞泄漏；指尖密封磨损后迟滞泄漏规律表现出先减小后增加再降低的变化趋势；与国内外试验结果的对比分析初步验证了提出的计算方法,为指尖密封动态性能设计方法研究提供了参考.

Analysis of leakage characteristics of finger seal based on system responses

The current work obtained the seal rotor displacement excitation through studying the association rules of rotor speed,rotor unbalanced force and rotor runout based on dynamic working characteristics of finger seal.Then,a dynamic computational model of finger seal system was constructed.The leakage clearance computation method was researched according to the dynamic displacement response characteristics from the constructed model.Then the dynamic leakage calculation method was constructed and the leakage analysis work was conducted.The results preliminarily shows that dynamic displacement response changes with the rotor excitation time in every rotation period.The dynamic leakage clearance produced by dynamic displacement response also changes with the rotor excitation time.The results also indicate that leakage numerical size is affected by working conditions,installation conditions and the abrasion degree of finger boots.The method was validated by the computational example of a special engine and the comparison of calculating results and test data in references.The research work can provide valuable reference for dynamic performances design and study of finger seal.