The Effect of Anisotropic Support on Rotor Instability Due to Fluid Leakage

The instability caused by fluid leakage leads to limited performance in turbomachines. This instability may be improved by using flexible bearing supports with anisotropic stiffness. With a simplified model this effect is investigated, including the influence of many parameters. The results show that the optimum range of anistropy is strongly dependent on the parameters of the rotor-bearing system. In this paper an explanation from an energy point of view is presented to clarify the different stability behaviors with anisotropic bearing support.