基于分形理论的接触式机械密封端面泄漏模型

Leakage Model of Contacting Mechanical Seal Based on Fractal Theory

目前对于密封的大多数研究都基于密封端面形貌和摩擦条件不变的假设,且大多忽略了密封端面形貌对泄漏的影响,也并未从微观角度考虑端面形貌的影响.基于分形理论,将动、静环端面的接触简化为粗糙表面与理想刚性平面的接触,建立了机械密封的泄漏模型,并对各分形参数、端面比载荷和材料参数对泄漏率的影响进行了研究,得到了机械密封分形维数D和端面比载荷p_g与其泄漏量Q成反比;而特征长度尺度参数G和综合弹性模量E与其泄漏量Q成正比.计算泄漏率与实验数据验证了模型的准确性.

At present,most studies about the seal are based on the assumption that the seal surface topography and friction conditions are changeless. The influence of the seal surface topography on the leakage is mostly ignored as well as the effect of the microscopic perspective. Based on the fractal theory,the contact betw een surfaces of dynamic and static rings was simplified to the contact betw een rough surface and the ideal rigid plane,and a mechanical seal leakage model was established. The effects of fractal parameters,the surface unit load and material parameters on leakage rate were studied to obtain that the mechanical seal fractal dimension D and the end face specific load p_g were inversely proportional to the leakage amount Q. The characteristic length scale parameter G and the comprehensive elastic modulus E were proportional to its leakage amount Q. The calculated leakage rate and experimental data verify the accuracy of the model.