Internal flow and bearing characteristics in tilting pad journal bearing with fluid structure intersection

Abstract

Journal bearings have the advantage of being damped. However, at high rotational speeds, self-excited oscillations called oil whip occur, leading to damage of bearing and shafts. Tilting Pad Journal Bearings are used in high-speed rotating machinery as they are effective against oil whip. The Reynolds equation has been used as a typical calculation method to investigate bearing characteristics, but it is difficult to apply when the bearing is complex. In this paper, a prediction method of bearing characteristics of Tilting Pad Journal Bearing using CFD was constructed. To simulate the motion of the pad as it oscillates against the fluid force, Dynamic Fluid Body Intersection was studied. In order to compare with the calculation results, an active oscillating rotor using magnetic bearings was constructed. As a result, the calculation results were roughly consistent with the experimental results, and a prediction method by CFD was constructed.