利用Navier-Stockes方程和有限体积法,求解斜面滑块润滑模型的承载力和摩擦力,研究形貌高度较大时,表面形貌影响下非牛顿介质的润滑效果,获得用传统的包含表面形貌统计模型的雷诺方程方法难以获得的流场的细节信息。数值结果显示:在规则横向条纹形貌的作用下,形貌突变处出现压力突变;当形貌高度大于1%油膜厚度时才对润滑结果有较大影响,承载力和压差阻力随形貌高度的增加而增加,摩擦阻力随之下降,总阻力基本保持不变;当形貌高度大于油膜厚度的10%时,摩擦阻力随之上升,总阻力迅速增加。非牛顿介质幂律模型参数对润滑结果的影响远大于形貌参数的影响,但其并不影响承载力等结果随形貌高度变化的趋势,选择合适的润滑材料参数是改善润滑的关键因素。
The Navier-Stockes equations and finite volume method are applied to solve the load capacity and drag force of an inclined slider model. The details of the flow field are acquired, and the effect of large amplitude surface topography in non-Newtonian fluid lubrication is studied. The numerical results show that the pressure mutation occurs at the edges of bulges of the surface topography. When the height of the bulges is more than 1% lubricant thickness, the height of the bulges takes an obvious effect on the lubrication results. The load capacity and the pressure drag increase as the height of the bulges increases, while the friction drag decreases and the total drag force keeps constant. When the height of the bulges is more than 10% lubricant thickness, the friction force begins to increase and the total drag force increases rapidly. The parameter of non-Newtonian fluid affects the lubrication results more greatly than the height of the bulges does, but it does little effect on the variation process of the forces under different surface topography. In practice application, to choose the lubricant with proper parameters is the key factor in the improvement of lubrication.