基于改进C-S模型的水润滑轴承湍流流场计算方法

Turbulence field calculation method for water lubricated bearing based on improved C-S model

针对C-S湍流模型中存在对压力梯度影响考虑不够充分、只适用于以速度流动为主的动压轴承流场计算、不适于Couette流和Poiseuille流动共同作用的水润滑轴承湍流流场计算等方面的不足,该文在关于压力梯度影响方面的已有试验研究成果的基础上,对C-S模型进行了改进,充分计入压力梯度的影响,使模型更为完善。文中采用免疫粒子群算法进行数值求解。为了提高计算精度与计算效率,进行粒子群的初始化,合理确定根据改进模型得出的解析形式近似解,使其位置能充分接近精确解,从而有效减少迭代计算量。在迭代过程中,对求解变量及方程特点进行分析并采用针对性的不同变异方法加快其迭代速度。并将该文理论计算值与已有的湍流工况下轴承流场的实验结果进行了对比,发现二者之间具有较好的一致性,故该方法可用于计算分析Couette流与Poiseuille流共同作用的复杂湍流流场。

Although Cebeci-Smith turbulent model is widely used and gives satisfied results generally, some inaccurate results are obtained for turbulent flows with larger pressure gradient like water lubricated hydrostatic bearings with coupled Couette flow and Poiseuille flow. Based on available experiment results, an improved Cebeci-Smith turbulent model is presented to take the influence of large pressure gradient into account. The improved turbulent model can be applied to analyze fluid film with combined Couette flow and Poiseuille flow. By analyzing the characteristics of variables and equations in the model, simplified approximate formulae are derived to initialize particle＇s position which may close the exact solution and shorten the solution process. The numerical results by presented model agreed well with available experimental data of journal bearing in turbulent regime.