表面粗糙对线接触低弹性模量弹流润滑性能的影响

Effect of roughness on lubrication of low elastic modulus in line contact

实际润滑表面上的粗糙会导致润滑压力和膜厚发生明显变化。由于软材料弹流润滑膜厚远小于相似情况下硬材料的膜厚，所以在软弹流润滑中考虑粗糙度的影响更为重要。利用多重网格的数值法得到了大量软弹流数值解，用它分析了表征谐调粗糙的峰高、波长和相位等参数对润滑特性的影响。由于膜厚是润滑性能的重要参数，这里着重讨论了粗糙度对各特征膜厚的影响。对计算结果的分析表明：粗糙度对膜厚的影响可以分为两个区间，小波数区和大波数区。在小波数区，粗糙的峰高、波长和相位的变化对润滑各特征膜厚的影响十分明显。随粗糙度的波数增大，粗糙的影响趋于稳定。最后给出了模拟接触区膜厚的近似公式。

The roughness on real surfaces may significantly cause the variation of pressure and film thickness of lubricant. Moreover, under a similar condition the film thickness of elastohydrodymic lubrication of the softer material is much thinner than that of the harder one. Therefore, it is more important to consider the influence of roughness in the soft elastohydrodynamic lubrication. With the multi grid method, a great number of solutions of soft elastohydrodynamic lubrication have obtained to analyse the influence of amplitude, wavelength and phase of the sinuous roughness in soft elastohydrodynamic lubrication. Since film thickness is a key parameter in lubrication, the discussion is focused on some typical film thicknesses. The calculated results show that the influence region of roughness on the film thicknesses can be divided into two parts:the large wave number part and small wave number part. In the small wave number part, the influences of the amplitude, wavelength and phase of roughness are significant. With the increase of the wave number, the influence of roughness tends to be steady. Finally, a formula is presented to simulate the lubrication film of the contact region in large wavelength number.