基于有限元仿真的指尖密封准动态性能分析方法

Quasi-Dynamic Performances Analysis of Finger Seal Based on Finite Element Simulation

关键词:  指尖密封  磨损  泄漏  准动态性能  柔性密封  有限元仿真

Key words:  Finger seal  Wear  Leakage  Quasi-Dynamic performance  Flexible seal  Finite element simulation

摘要:

指尖密封性能的量化表达和计算效率一直是设计人员关心的问题。针对指尖密封的工作特点，对其泄漏机理和磨损特性进行了分析。基于有限元分析构建了指尖密封性能量化表达的准动态性能模型，解决了理论设计中磨损和泄漏特性难以计算和计算工作量较大的问题。采用该方法的研究结果表明环境温度升高到300℃时，泄漏率较之27oC条件下降低了65%，磨损率升高了约4%；指尖片厚度从0.1mm增加到0.5mm时，泄漏率降低了70%，磨损率升高了28%；同时指尖曲梁个数、转子转速和压差对指尖密封性能同样具有重要影响。分析初步表明，提出的计算方法能够较好地反映指尖密封实际动态特性，为指尖密封性能设计提供了快捷高效计算方法。

Abstract:

Quantitative expression and calculation efficiency of finger seal performance are always the concern problems for designers. The Leakage mechanism and wear characteristics are analyzed in this work based on the working characteristics of finger seal. Then，the quasi-dynamic computation model of wear and leakage for finger seal system is built by using finite element analysis method. The problems that quantitative expression and calculation efficiency of the wear and leakage performances are usually hardly calculated or need huge calculation in theoretical design are completely solved by using this quasi-dynamic computation model. The research results based on the provided method show that the leakage in 300℃ is even 65% smaller than the leakage in the 27℃，and the rate of wear rises 4%. When the thickness of finger element rises from 0.1mm to 0.5mm，the leakage reduces 70%，and the rate of wear rises 28%. At the same time，the study results show that the finger seal performances are also obviously affected by the number of finger stem，the rotor speed and pressure difference between high pressure chamber and low pressure chamber. The study results indicate preliminarily that the real dynamic performances of finger seal can be well reflected by the proposed calculated method. Therefore，the proposed method provides an efficient method for performances design as well as a theoretical reference in dynamical design to finger seal.