Abstract
The dynamic characteristics of cylindrical journal bearing with an axial oil supply groove are numerically analyzed by taking the film rupture and the reformation boundaries into consideration. The results, based on the assumptions of frozen cavity, constant cavity pressure, constant gas volume in the cavity and adiabatic charge of the gas are compared to each other. It is found that the oil film coefficients depend on the movement of the cavity boundary and the fluctuation of the cavity pressure. Adiabatic change is the most appropriate assumption if the gas is conserved in the cavity. However, the dynamic properties of a heavily loaded bearing can reasonably be estimated by constant pressure assumption. On the other hand, those of a lightly loaded bearing by constant volume assumption.
