CFD Analysis of a Combined Bearing for Gas Turbine Generator

A combined bearing, which functions as both a journal and thrust bearing, is used to support the rotor of a gas turbine generator and has a compact size. The primary objective of this study was to confirm the oil flow lines of a thrust bearing using computational fluid dynamics (CFD). The oil nozzles between the thrust pads were confirmed to supply oil to the thrust pads. Another objective was to simulate the performance of the bearing, using two-way fluid-structure interaction (FSI). The load capacity of the bearing was found to be inferior due to the incorrect position of the pivot, which is crucial for the load capacity and minimum oil gap. A design of experiment (DOE) was performed to improve the minimum oil gap. The optimal point was selected using local sensitivity curves, in which yielded a 2.7 times increase in the minimum oil gap compared to the previous pivot position.