干气密封摩擦界面法向接触刚度分形模型

Fractal model for the normal contact stiffness of frictional interface in dry gas seals

为揭示干气密封摩擦界面的摩擦振动规律,用分形参数表征干气密封摩擦界面形貌特性,根据重新建立的微凸体接触变形方式,以及概率理论建立了干气密封摩擦界面法向接触刚度分形模型。通过与相关实验数据和模型的对比,验证了该模型的合理与正确。对影响法向接触刚度的关键因素进行了数值分析,研究结果表明:法向接触刚度随分形维数、真实接触面积的增大而增大;当接触面积一定时,法向接触刚度随特征尺度、摩擦因数的增大逐渐减小。相比于分形维数、特征尺度对法向接触刚度的影响,摩擦因数的影响相对较小。该研究结果为进一步研究干气密封摩擦振动奠定了基础。

In order to reveal the frictional vibration behaviors of the frictional interface in dry gas seals,the end face morphology of dry gas seals was characterized by fractal parameters.According to a re-established contact deformation model for the micro-convex body and the probability theory,a fractal model for the normal contact stiffness of dry gas seals was established.The rationality and correctness of the model was verified by the comparison of the related experimental data with the model results.The key factors influencing the normal contact stiffness were analyzed numerically,and the results show that the normal contact stiffness increases with the increase of the fractal dimension and real contact area.When the contact area is fixed,the normal contact stiffness decreases with the increase of the characteristic scale and friction coefficient.The effect of the coefficient of friction on the normal contact stiffness is relatively small compared to the fractal dimension and the characteristic scale.The results provide a foundation for further study of the frictional vibration of dry gas seals.