金属封严环泄漏率预测方法

针对金属封严环设计中泄漏率估算问题，综合对密封系统宏观结构和微观表面接触变形的考量，提出一种基于数值计算的泄漏率预测方法。对密封整体结构进行计算，以计算值（接触应力、接触面积）为输入参数，以表面粗糙度为评价指标建立微观粗糙表面，使用有限元法（FEM）进行接触计算后建立泄漏通道模型，在对泄漏缝隙内流体流动特性确定后通过计算流体力学（CFD）方法计算得到泄漏率。使用密封试验台进行泄漏率试验，将计算值与试验结果相比较。研究表明:随着接触应力增加、表面粗糙度值降低以及内外腔压差增长，密封系统泄漏率逐渐减小；所提出的方法极大地摆脱了泄漏率获取对于试验仪器的依赖性，并能够较为有效地预测金属密封结构的泄漏率，对先进的金属封严环的设计和评估具有重要意义。 

Method to predict leakage rate of metal seal ring

Targeting the problem of estimating the leakage rate in the design of metal seal ring, a method to predict the leakage rate based on numerical calculation was proposed. This method combined the macro-structure of the sealing system and micro-surface contact deformation considerations. The overall structure of the seal was calculated firstly, and its calculated values (contact stress, contact area) were taken as the input parameters. The rough microscopic surface with the surface roughness as the evaluation index was established. Using finite element method (FEM) for contact calculation, the leak channel model was established. After the fluid properties in the leakage gap were determined, the leakage rate was calculated by computational fluid dynamics (CFD) method. Leakage rate test was performed using a sealed test bench and the calculated values were compared with the test results. The result shows that as the contact stress increases, the surface roughness decreases, and the pressure difference increases, the leakage rate of the seal system gradually decreases. With this proposed method, the aquisition of leakage rate value relies little on the test equipment, helping to predict the leakage rate of metal seal structure effectively, while playing an important role in the design and evaluation of advanced metal seal rings.