基于异频扰动和CFD技术的滑动轴承动力特性系数识别方法

目前CFD技术已广泛应用于滑动轴承的数值仿真中,但还存在两个问题,相对于传统的通过求解Reynolds方程获得流体压力场和油膜力的方法,如何通过CFD计算结果来识别得到动力特性系数,以及CFD方法误差有多大。针对这些问题,本文基于同幅异频位移激励技术,同时充分考虑惯性力、刚度、阻尼交叉项等因素给出了一套适用于挤压油膜阻尼器、可倾瓦轴承、固定瓦轴承等多种模型的动力特性识别方法,应用该方法可以一次性识别出油膜的动力特性系数。通过滑动轴承算例与短圆瓦轴承刚度阻尼理论解进行对比,验证了该方法的准确性。

Method for Identifying Dynamic Coefficients of Sliding Bearing Based on Different Frequency Disturbance and CFD Technology

CFD technology has been widely used in numerical simulation of sliding bearing, but there are still two problems. Compared with the traditional method of obtaining fluid pressure field and oil film force by solving Reynolds equation, it is important how to identify the dynamic coefficients by CFD simulation results and how much error the CFD method has. To solve those problems, considering the inertial force, stiffness, damping cross-section and other factors, a dynamic coefficients identification method is proposed based on the same amplitude and different frequency displacement excitation technology. The method can be used to identify the dynamic coefficients of the oil film at one time for squeeze film damper, tilting pad bearing, fixed tile bearing, etc. By the comparison of the cylindrical journal bearing example and the theoretical solution of stiffness and damping with the short bearing model, it is found that when eccentricity ratio is 0.5, the maximum error of main and cross stiffness coefficients is 2.1% and 18.6%, and the maximum error of main and cross damping coefficients is 30.8% and 54.6%.