【作者】 韩清刚；

【导师】 吴建康；

【作者基本信息】 华中科技大学 ， 流体力学， 2004， 硕士

【摘要】 本文采用算子分裂/有限元法计算微极性流体润滑剂的螺旋槽径向轴承承载力、粘性阻力、润滑油膜刚度系数和阻尼系数等特征量,研究轴承的动力特性和稳定性问题。在液体润滑轴承运转过程中,润滑油膜的负压力区中会出现空泡。空泡对螺旋槽液体润滑轴承的稳定性有很大影响。在液体润滑轴承动力性能计算中,空泡区的边界条件是一个关键问题。本文采用满足全流场质量连续的JFO边界条件,采用微极性流体的广义雷诺方程来求解油膜压力分布,进而获得油膜承载力和粘性阻力等轴承动力特性量;采用小参数摄动法得出油膜压强扰动方程,并采用有限元法解出扰动压强,积分扰动压强获得油膜的阻尼系数和刚度系数,进而求得了表示轴承油膜稳定性的临界转子质量。微极性流体的粘弹特性由耦合数和分子特征长度两个参数决定。本文研究结果表明,与牛顿流体润滑液相比,以微极性流体为润滑液可以提高螺旋槽径向液体润滑轴承的承载力,和小偏心时的稳定性。同时摩擦阻力也略有增加。在高耦合数下,润滑油膜厚度和分子特征长度的比值越小,油膜承载能力越高,稳定性越好。选用合理参数的微极性流体为润滑剂,可以提高螺旋槽径向滑动轴承的承载力和稳定性。更多还原

【Abstract】 This work employs operator-splitting method (OSM) / finite element method (FEM) to study dynamic performance and the stability of liquid-lubricated herringbone grooved journal bearing (HGJB) with micro-polar lubricants. Load capacity, friction resistance, stiffness/damping coefficients and critical rotor mass were investigated. In liquid-lubricated film of a hydrodynamic bearing, cavities may occur in negative-pressure region. The film cavity plays a significant role to the film stability of a bearing. The boundary conditions of the cavity region are extremely important to bearing load capacity and film stability. In this paper, the JFO condition, satisfied with global mass continuity, is incorporated into an universal Reynolds equation with micro-polar fluid which is solved for the oil film pressure using OSM and FEM. The bearing load capacity and friction resistance were given, and stiffness/damping coefficients and critical rotor mass were obtained by solving a pressure perturbation equation with micro-polar lubricants.Visco-elasticity of micro-polar fluid is characterized by two parameters of coupling number and molecular characteristic length. Numerical results indicate that under small eccentricity the film stability and load capacity of HGJB with micro-polar fluid lubricants are generally better than those with Newtonian fluid lubricants. At the same time, the bearing friction resistance is increased slightly. Under the high coupling number, the smaller the ratio of film thickness to molecular characteristic length, the higher the load capacity and the better the stability of the HGJB. This paper also shows that load capacity and the film stability of HGJB can be improved by optimizing parameters of micro-polar lubricants.更多还原