基于6DOF模型及动网格的动静压轴承刚度阻尼数值计算

针对传统雷诺方程求解三维油膜流场特性的局限性,提出基于6DOF模型及动网格的动静压轴承刚度阻尼计算方法.以具有典型结构形式的液体动静压轴承为例,通过加载6DOF自定义程序,采用非线性迭代方法计算外载荷作用下轴心轨迹的瞬态变化过程,得到轴颈在外载荷作用下的静平衡位置；通过嵌入UDF宏程序以动网格更新方法实现对轴颈在静平衡位置的扰动,求解Navier-Stokes方程得到轴颈扰动前后位置变化后的瞬态油膜力,利用差分法求得动静压轴承油膜刚度和阻尼,并分析了不同转速下轴承刚度和阻尼的变化规律.

Numerical calculation of stiffness and damping for hybrid bearings based on a 6DOF model and the dynamic mesh method

To overcome the limitation of traditional Reynolds equation in solving three dimensional oil film flow field, a numerical method based on six-degree-of-freedom (6DOF) model and dynamic mesh was proposed to obtain the stiffness and damping of a hybrid bearing. The hybrid bearing with typical structure was taken as an example. By developing a customization program of the 6DOF model and using the nonlinear iterative method, the transient change process of axis trajectory under an external load was calculated, and then the static equilibrium position of axle neck under the external load was obtained. By embedding the UDF macro program, a perturbation of the axle neck in the static equilibrium position was realized by the dynamic mesh updating method. The transient oil film force caused by the perturbation was calculated by solving the Navier Stokes equation, and the oil film stiffness and damping of the hybrid bearing were obtained by the difference method. The variation of bearing stiffness and damping at different rotational speeds was also analyzed.