In the field of turbomachinery such as centrifugal compressors and steam turbines, the aim has been to reduce the size and number of stages by increasing the speed and load. As a result, however, the rotordynamics stability margin tends to decrease due to the increase in the fluid destabilization force (hereinafter referred to as destabilization force) generated in the impeller and blade area, as well as the sealing areas. In order to increase the speed and load of turbomachinery, it is indispensable to improve the rotordynamics stability by reducing the destabilization force. On the other hand, it is difficult to predict the destabilization force, which is related to the flow phenomena in a narrow area and small flow rate. Therefore, we have developed a structure for reducing the destabilization force for centrifugal compressors using numerical analysis technology.
