CIESC Journal ›› 2017, Vol. 68 ›› Issue (12): 4665-4674.DOI: 10.11949/j.issn.0438-1157.20170660

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Hydrodynamic performance of spiral groove liquid film seals based on JFO boundary condition and power law model

WANG Yunlei, HAO Muming, LI Zhentao, LI Yongfan, SUN Xinhui, XU Lushuai   

  1. Institute of Sealing Technology, China University of Petroleum, Qingdao 266580, Shandong, China
  • Received:2017-05-22 Revised:2017-06-25 Online:2017-12-05 Published:2017-12-05
  • Supported by:

    supported by the National Natural Science Foundation of China (51375497) and the Key Research Program of Dongying (2016YF01).

基于JFO空化和幂律模型的螺旋槽液膜密封流体动压特性

王赟磊, 郝木明, 李振涛, 李勇凡, 孙鑫晖, 徐鲁帅   

  1. 中国石油大学(华东)密封技术研究所, 山东 青岛 266580
  • 通讯作者: 郝木明
  • 基金资助:

    国家自然科学基金项目(51375497);东营市重点研发项目(2016YF01)。

Abstract:

The performance of liquid film seals is significantly affected by non-Newtonian behavior of lubricating fluids at seal interface. A mathematical model of spiral groove non-Newtonian liquid film seal was established by combination of mass conservation at JFO cavitation boundary condition and power law model of non-Newtonian fluids. The governing equation was discretized by finite difference method and solved by SOR iterative algorithm to obtain liquid film pressure distribution. The effects of non-Newtonian fluids on sealing performance were analyzed, including load-carrying capacity, leakage, friction torque, and cavitation occurrence in liquid film. The results indicate that with the increase of power law index, the load-carrying capacity first increases then decreases but the leakage and cavitation rate always increase and the friction torque consistently decreases. At power law index n=0.96, non-Newtonian fluids had increase by 4.6% in the load-carrying capacity and 0.3% in the friction torque but decrease by 98.6% in the cavitation rate of sealing face and 5.8% in leakage than Newtonian fluids. When operating parameters were changed, non-Newtonian fluids with various power law indices showed similar trending behavior of liquid film hydrodynamic performance. Suitable lubricant selection is important to improve sealing performance of liquid films.

Key words: spiral groove liquid film seals, power law model, non-Newtonian fluids, JFO boundary condition, hydrodynamic performance

摘要:

密封端面间润滑流体的非牛顿特性对密封的性能有重要影响。基于满足质量守恒的JFO空化边界条件及描述流体非牛顿特性的幂律模型,建立了考虑流体非牛顿特性的螺旋槽液膜密封数学模型。采用有限差分法对控制方程进行离散,通过SOR迭代方法对离散方程进行求解,得到了密封端面液膜压力分布。探讨了润滑流体的非牛顿特性对螺旋槽液膜密封的液膜承载能力、泄漏量、摩擦扭矩等性能参数及液膜中空化发生情况的影响规律。结果表明:随着幂律指数的增大,液膜承载能力先增大后减小,泄漏量和空化率增大,摩擦扭矩减小;幂律指数为0.96时,相对于牛顿流体,液膜承载能力提升约4.6%,密封端面空化率下降约98.6%,泄漏量下降约5.8%,摩擦扭矩增加约0.3%;随着操作参数的改变,不同幂律指数下的流体动压性能参数变化规律具有相似性;润滑流体的合理选择对液膜密封性能改善有重要意义。

关键词: 螺旋槽液膜密封, 幂律模型, 非牛顿流体, JFO边界条件, 流体动压特性

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