MODELLING AND SIMULATION OF DYNAMIC BEHAVIOR OF WAVE JOURNAL BEARINGS USING A TRANSIENT APPROACH

摘要

The purpose of this paper is to present a theoretical model to simulate the dynamic behaviour of a wave journal bearing by using a transient approach. The main advantage of this model is that it can predict what happens after the bearing film instability occurs. The journal centre trajectory is obtained by integrating the non linear differential equations of motion. The bearing fluid film forces are calculated by solving the transient Reynolds equation at each time-step location of the journal centre. The turbulence effects and the variation of the lubricant properties with temperature are also considered. The model is validated by comparing the numerical simulations with experimental data. Two types of simulations, with and without taking into account the inherent small unbalance of the shaft, were performed. It was found that under unstable conditions only the simulations that take into consideration the small shaft run out can predict the presence of both the synchronous and sub-synchronous frequencies.