粘弹性非Newton介质润滑流变特性的频域分析

为了解粘弹性非Newton介质在径向轴承润滑中的效果,定义了差分粘度和剪切频率表示非Newton介质的流变特征。差分粘度的幅频响应特性表明,非Newton介质的粘度变化不仅受润滑材料动态参数的影响,而且与润滑所处的剪切频率有关。基于非Newton介质的普遍Reynolds方程,对非Newton介质的径向轴承润滑进行数值计算,在不同的动态参数和剪切频率范围的影响下,非Newton介质润滑的承载力、摩擦力等并不总是高于或低于Newton介质的润滑结果。这一结果对选择合适的材料参数和工作转速以改善非Newton介质的润滑效果具有指导意义。

Frequency-domain analysis of rheological properties of viscoelastic non-Newtonian medium

The effects of viscoelastic non-Newtonian lubricants in journal bearing lubrication were analyzed based on the differential viscosity and the shear frequency defined in the frequency domain which were used to represent the rheological properties of non-Newtonian fluids. The amplitude frequency response of the differential viscosity shows that the viscosity variation is not only affected by the material parameters of the lubricants, but also by the shear frequency. A modified Reynolds equation was then used to analyze the journal bearing lubrication. The load capacity and the friction force of non-Newtonian lubricants for different material parameters and shear frequencies are not always higher and not always lower than those of Newtonian lubricants. The amplitude frequency response of the differential viscosity can be used to improve the lubrication effect by properly selecting the lubricant's material parameters and the working speed.