Effect of starvation on film thickness and traction under elastohydrodynamic rolling and sliding conditions
Effect of starvation on film thickness and traction under elastohydrodynamic rolling and sliding conditions
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弹性流体动力滚动和滑动条件下饥饿对薄膜厚度和牵引力的影响
DOI：
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发表时间：
1975
期刊：
影响因子：
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通讯作者：
L. Wedeven
中科院分区：
文献类型：
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作者：
L. Wedeven
牵引测量饥饿的弹流条件下获得的点接触几何形状。同时测量膜厚度和入口润滑剂边界的位置。采用光学干涉法测量薄膜厚度。滚动和滑动组合条件下的饥饿膜厚度随入口边界位置的变化而变化，与之前在纯滚动条件下发现的情况相同。当通过雷诺润滑分析计算入口区域中的流体速度分布时，可以看到回流发生在入口区域的一部分上。回流对于建立淹没条件是必不可少的。如文献中所建议的，入口区域内某些流体速度条件的位置并不能充分描述饥饿的开始。对于相同的滑滚比，观察到饥饿薄膜比淹没薄膜具有更大的牵引力。饥饿条件下的牵引力测量也进行了比较，在赫兹区域的等效剪切速率与淹没条件下。当赫兹区域内的剪切速率低且膜严重饥饿时，测得的牵引力低于预期。这可能是由于当入口区域严重不足时，在入口区域中产生的大的压力梯度所产生的大的剪切应力。
Traction measurements under starved elastohydrodynamic conditions were obtained for a point-contact geometry. Simultaneous measurements of the film thickness and the location of the inlet lubricant boundary were made. Optical interferometry was used to measure film thickness. The thickness of a starved film for combined rolling and sliding conditions varies with the location of the inlet boundary in the same way as previously found for pure rolling conditions. When the fluid velocity distribution is calculated in the inlet region by a Reynolds lubrication analysis, backflow is seen to occur over a portion of the inlet region. Backflow is essential for the establishment of a flooded condition. The location of certain fluid velocity conditions within the inlet region, as suggested in the literature, does not adequately describe the onset of starvation. For the same slide-roll ratio a starved film was observed to possess greater traction than a flooded film. Traction measurements under starved conditions were also compared with those under flooded conditions for equivalent shear rates in the Hertzian region. When the shear rates within the Hertzian region were low and the film was severely starved, the measured tractions were lower than expected. This may be due to large shear stresses developed by the large pressure gradients that are generated in the inlet region when it is severely starved.