基于流固耦合的滑动轴承非线性油膜动特性研究

Research on Dynamic Characteristics of Sliding Bearing Nonlinear Oil-film Based on Fluid-structure Interaction

针对采用传统静态滑动轴承动力特性系数分析转子从启动到稳定在平衡位置这段时间内瞬态响应的误差较大的问题,提出了采用有限变分法和Newmark-β法相结合的非线性油膜动特性动态分析方法。该方法首先采用有限变分法计算非线性油膜动力特性系数,解决了采用有限差分法时多次迭代的时效问题,大大提高了计算效率;然后根据计算得到的非线性油膜动力特性系数,通过Newmark-β法分析转子系统的瞬态响应,用学科间迭代方法实现了非线性油膜动力特性系数与转子瞬态响应之间的流固耦合;最后以Jeffcott转子系统为例,对比研究了传统静态分析方法与动态分析方法。结果证明,采用动态分析方法得到的转子系统瞬态响应幅值更小,精度更高。

From initial start to stabilize in a balanced position, the shaft was changing constantly during this time, analysis of rotor transient response by traditional dynamics coefficients of hydrodynamic journal bearing was not accurate. A dynamic analysis method was proposed herein to study the transient response of the dynamics characteristic coefficient of hydrodynamic journal bearing by the coupling process of variation method and Newmark-β.First, dynamics characteristic coefficient of hydrodynamic journal bearing nonlinear oil-film was achieved by the variational method instead of the finite difference method in order to solve prescription generated by the iteration. Calculation efficiency was improved greatly. Then, the fluid-structure interaction of rotor dynamics analysis based on Newmark-β and the dynamics characteristic coefficient of journal bearing was achieved by the interdisciplinary iteration at every steps. At last, the dynamic coefficient and static coefficient of Jeffcott rotor system, for example, were analyzed respectively. By the comparison of the results, the amplitude of the transient response of the rotor system by dynamic analysis method is smaller, higher accuracy is verified.