Dynamic Forced Performance of Fluid Film Bearings Operating with Air Entrainment

带空气运行的油膜轴承的动态受力性能

• 批准号: 9820845
• 负责人: Luis San Andres
• 金额: $ 17.21万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9820845&HistoricalAwards=false
• 关键词: Dynamic; Forced; Performance; Fluid; Film

9820845San AndresSqueeze film dampers (SFDs) are virtually the only means to provide structural isolation and vibration energy dissipation in aircraft engines and light hydrocarbon centrifugal compressors. These high performance rotor-bearing systems operate above the natural frequencies of the flexural modes. When the system passes through critical speeds large dynamic loads are induces. This may cause very high amplitude vibrations at the rotor and bearing supports. Under these operating conditions, oil lubricated SFDs as well as dynamically loaded journal bearings are prone to develop regions where the lubricant is foamy, which greatly reduces their dynamic force capacity. This pervasive phenomenon is well known in industry but still lacks proper physical understanding and sound analytical modeling. In this study measurements of dynamic pressure fields and rotor motions will be performed on a modified journal bearing and SFD test rig operating with a foam-like lubricant and under dynamic loads exerted from a shaker system. Fundamental understanding of bubbly flow fields will be gained through high-speed photography studies and image identification techniques which will be used to track the time evolution and spatial structure of the air bubbles within the thin film flow. In addition, imbalance response measurements in an industrial size rotor supported on SFDs, constructed with prior NSF support, will be conducted to identify damping force coefficients within an operating region where air entrapment occurs naturally. The research products will be valuable to the design of SFDs in critical turbomachinery applications, of process fluid film bearings and of seals in multiple-phase pump applications.***

挤压油膜阻尼器（SFD）实际上是在飞机发动机和轻烃离心压缩机中提供结构隔离和振动能量耗散的唯一方法。这些高性能的转子轴承系统在弯曲模式的固有频率以上运行。当系统通过临界转速时，会产生较大的动载荷。 这可能导致转子和轴承支撑处的非常高的振幅振动。在这些操作条件下，油润滑的SFD以及动态加载的轴颈轴承很容易出现润滑剂泡沫区域，这大大降低了它们的动态承载力。这种普遍现象在工业中是众所周知的，但仍然缺乏适当的物理理解和合理的分析建模。 在这项研究中，动态压力场和转子运动的测量将进行修改后的轴颈轴承和SFD试验台与泡沫状润滑剂和振动筛系统施加的动态载荷下运行。通过高速摄影研究和图像识别技术，将被用来跟踪薄膜流内的气泡的时间演化和空间结构的气泡流场的基本认识。此外，将在SFD上支撑的工业尺寸转子中进行不平衡响应测量，该转子由先前的NSF支持构建，以确定自然发生空气夹带的操作区域内的阻尼力系数。研究产品将对关键润滑油应用中的SFD设计、过程流体膜轴承设计和多相泵应用中的密封件设计有价值。***