纳米气泡润滑动压水润滑轴承的静动态特性

Static and Dynamic Characteristics of Water-lubricated Hydrodynamic Bearings Considering Nano-bubbles Effects

空化、两相流现象是滑动轴承润滑中的典型现象之一,影响着水润滑轴承的静态和动态特性。基于统计物理学及多相流理论,建立大量纳米气泡对流体的阻力模型,以及含纳米气泡的两相流体动力润滑理论模型,并采用有限差分法求解得到压力场、空化气泡数分布及动压水润滑轴承静、动态特性系数,分析并讨论空化两相流对水润滑轴承静、动态特性的影响。结果表明,与Reynolds边界相比,空化条件下轴承的承载力和偏位角均呈增大趋势,动态刚度和阻尼系数也出现不同程度的增加。

Phenomena of cavitation and two phase flow are often occurred in hydrodynamic bearings, and have an influence in the static and dynamic characteristics of the water-lubricated bearing.A drag model about a large number of nanobubbles was built based on statistical physics and multi-fluid theory, and a hydrodynamic lubrication theoretic model with nano-bubbles of two phase flow was set up.The circumferential pressure, cavitation bubble number distribution and static and dynamic characteristics of water-lubricated bearing were solved by using finite difference method.The effect of cavitation and two phase flow on the static and dynamic characteristics of water-lubricated bearing were analyzed.The results show that bearing capacity and attitude angle are all increased under cavitation condition compared with Reynolds boundary condition, and the dynamic stiffness and damping coefficient are also increased in different extend.