基于渗流模型的平面密封机理研究

Study for Planar Seal Principle based on Percolation Theory

共轨系统喷射压力的提高,对高压密封提出了严峻挑战,密封能力很大程度依赖于密封面的加工精度,在现有加工能力下经济地实现可靠密封对降低成本增加效益具有重要意义,考虑到流体在多孔介质中的流动与在密封端面间的流动具有类似特征,将渗流理论中的渗流阀值引入平面密封理论中,得出了接触率与密封性之间的关系。对于无规则纹理的随机分布粗糙表面,接触率达到41%以上时即能实现密封,仿真结果验证了这一结论的正确性。

It will put forward severe challenge to high pressure seal with the increase of common rail system injection pressure. The sealing ability largely depends on machining accuracy of sealing surface. It is of great significance to reduce costs and increase efficiency in case realizing sealing capability economically. Percolation threshold was introduced to planar seal based on percolation theory considering fluid flow in porous media and flow between sealing surfaces,therefore the relationship between contact rate and tightness was obtained. Sealing capacity can be achieved as long as contact rate is greater than 41% for random distribution of irregular texture rough surface,meanwhile simulation results verified the correctness of this conclusion.