航空发动机刷式密封迟滞特性数值研究

Numerical study on hysteresis characteristics of aero-engine brush seals

为揭示刷式密封的迟滞规律,针对其结构特点,采用有限元方法分析了刷式密封系统动力学参数和结构工况参数之间的关系,在刷丝受力分析的基础上建立刷式密封系统质量—弹簧—阻尼等效动力学模型,研究了结构和工况参数对迟滞量、迟滞率和迟滞时间的影响规律,并进一步分析了结构参数对刷式密封迟滞特性影响的灵敏度。研究结果表明:迟滞量和迟滞率随刷丝直径的增大而减小,随刷丝长度、刷丝排列角度、后挡板保护高度的增大而增大;后挡板保护高度对迟滞时间没有影响。结构参数对迟滞量影响的灵敏度由小到大依次为后挡板保护高度、刷丝直径、刷丝排列角度、刷丝长度。将难以分析的数值模型转化为可控数值计算的研究方法,可为刷式密封的多目标结构优化研究提供一种新的研究思路。

In order to reveal the hysteresis law of a brush seal,according to its structural characteristics,this paper analyzes the relationship between the dynamic parameters of the brush seal system and the structural working parameters by using the finite element method.Based on the force analysis of the brush wire,a mass-spring-damping equivalent dynamic model of the brush seal system is established.The influence of the structural and working parameters on hysteresis amount,hysteresis rate and hysteresis time is studied,and the sensitivity of the structural parameters to the hysteresis characteristics of the brush seal is further analyzed.The results show that the hysteresis amount and hysteresis rate decrease with the increase of brush wire diameter,and increase with the increase of brush wire length,brush wire arrangement angle and rear baffle protection height.The rear baffle protection height has no effect on the lag time.The sensitivity of the structural parameters to the hysteresis is in an order of the rear baffle protection height,brush wire diameter,brush wire arrangement angle and brush wire length,from low to high.The research method of transforming the numerical model which is difficult to analyze into a research method of controllable numerical calculation can provide a new research idea for multi-objective structural optimization of brush seals.