Variations of an EHL Film Under Boundary Slippage
Variations of an EHL Film Under Boundary Slippage
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EHL 薄膜在边界滑移下的变化
DOI：
10.1007/1-4020-4533-6_20
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
P. Wong
中科院分区：
文献类型：
--
作者：
F. Guo;P. Wong
在经典的EHL理论中，典型的薄膜形状具有平行的平坦接触区和出口的收缩，这已经很容易地被数值分析和实验室试验所证明。近年来，润滑剂的极限剪切应力特性和边界滑移已被纳入EHL数值计算中。与传统EHL膜的平行平坦部分不同，在入口处出现了凹陷（膜厚增加），在下游接触区出现了凸起（膜厚减少）。在作者以前的一篇论文中，进行了一些故意设计的试验，得到了与数值结果定性相同的带有入口凹陷的膜形。最近，在广泛的滑滚比范围内进行了测试，发现了薄膜形状的有趣变化。本文报告了其中的一些结果。为了解释油膜偏差，我们暂时提出了一个粘度楔，即润滑油在边界面附近的有效粘度急剧下降。
The typical film shape in the classical EHL theory, featuring a parallel flat contact region and a constriction at the outlet, has been readily demonstrated by both numerical analyses and laboratory tests. Recently, the lubricant limiting-shear-stress property and boundary slippage have been incorporated into EHL numerical computations. Instead of the parallel flat part in the conventional EHL film, a dimple (film thickness increasing) occurs at the inlet, and a bump (film thickness decreasing) appears in the downstream contact region. In a previous paper by the authors, some purposely devised tests were carried out and a film shape with an inlet dimple, qualitatively the same as the numerical results, was obtained. More recently, tests have been carried out over an extensive range of slide-roll ratios and interesting variations of film shape are found. The present paper reports some of the results. A viscosity wedge, referred to as the drastic drop of the effective viscosity of lubricant adjacent to the bounding surfaces, is proposed tentatively to explain the film deviation.