Galmiche Bénédicte, Ponjavic Aleks, Wong Janet S S
Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK.
J Phys Condens Matter. 2016 Apr 6;28(13):134005. doi: 10.1088/0953-8984/28/13/134005. Epub 2016 Mar 3.
A novel methodology, based on the use of phosphorescence imaging, is applied to determine the local through-thickness velocity profile of lubricant in an elastohydrodynamic contact. The technique has spatial and temporal resolutions of 40 μm and 340 μs respectively and thus allows lubricant rheology to be investigated at conditions close to service conditions. The capability of the newly-developed method is verified by examining the flow of 5P4E polyphenyl ether, a lubricant base fluid used in very high temperature applications and is well-known for its high viscosity-pressure coefficient. Experimental results highlight the effect of the contact pressure on the velocity profile of this fluid in lubricated contacts. At low pressures, the velocity profile of 5P4E is close to linear, characteristic of Couette flow. As the local pressure increases, its velocity profile progressively deviates from a Couette profile and shear banding is evident at high pressure.
一种基于磷光成像的新型方法被应用于确定弹性流体动力接触中润滑剂的局部厚度方向速度分布。该技术的空间分辨率和时间分辨率分别为40μm和340μs，因此能够在接近实际工况的条件下研究润滑剂的流变学。通过研究5P4E聚苯醚（一种用于高温应用的润滑剂基础液，以其高粘度-压力系数而闻名）的流动，验证了新开发方法的能力。实验结果突出了接触压力对该流体在润滑接触中速度分布的影响。在低压下，5P4E的速度分布接近线性，这是库埃特流的特征。随着局部压力增加，其速度分布逐渐偏离库埃特分布，在高压下剪切带明显可见。
