高雷诺数下不同湍流润滑模型对水润滑橡胶轴承润滑特性的影响

Effect of different turbulent lubrication models on the lubrication characteristics of water-lubricated rubber bearings in high Reynolds number

为研究高雷诺数运行工况下的水润滑橡胶轴承的润滑特性,采用4种不同的湍流润滑数学模型,利用有限差分法,首先分析了4种不同湍流模型下的雷诺数,水膜厚度,衬层变形及水膜压力分布规律;然后对不同湍流润滑模型下的雷诺数随偏心率的变化规律进行了研究;最后讨论了4种湍流润滑模型下的承载力和最大膜压随偏心率、转速和间隙比的变化。结果表明:4种湍流润滑模型下的衬层变形和最大膜压均大于层流润滑,其大小顺序为:青木弘-原田正躬模型>Ng-Pan湍流模型>Constantinescu湍流模型>Hirs湍流模型;不同润滑模型下偏心率对雷诺数的影响不大。采用湍流润滑模型计算的承载力和膜压远大于层流润滑,层流假设不再适用高雷诺数下水润滑橡胶轴承的实际运行工况,同时在此工况下采用青木弘-原田正躬湍流润滑模型比其他3种润滑模型更为合理。随着偏心率的增大,承载力和最大膜压非线性增大;随着转速的增大,承载力和膜压近似线性增大;随着间隙比的增大,承载力非线性减小,膜压近似线性增大。

To study the lubrication characteristics of water-lubricated rubber bearings in high Reynolds number operating conditions,four different turbulent lubrication mathematical models were used,the distribution of Reynolds number,water film thickness,lining deformation and film pressure under four different turbulent lubrication models were analyzed using the finite difference method.Then the variation of Reynolds number with eccentricity under different turbulent lubrication models was investigated.Finally,the variation of the bearing capacity and maximum film pressure with eccentricity,rotating speed and clearance ratio under four turbulent lubrication models were discussed.The results show that the lining deformation and maximum film pressure of the four turbulent lubrication models are greater than that of laminar lubrication with their orders as follows:Aoki-harada turbulence model>Ng-Pan model>Constantinescu model>Hirs model;and the type of the lubrication model has slight effect on the Reynolds number.The bearing capacity and film pressure calculated by the turbulent lubrication model are far greater than those by the laminar flow model,and the laminar flow assumption is no longer applicable to the actual operating conditions of the water-lubricated rubber bearings in high Reynolds number.And the aoki-harada turbulent lubrication theory is more reasonable than the other three lubrication models.With the increase of eccentricity,the bearing capacity and the maximum film pressure increase nonlinearly;with the increase of the rotational speed,the bearing capacity and pressure increase linearly;with the increase of the clearance ratio,the bearing capacity increase nonlinearly,and the pressure increases approximately linearly.