抄録
It is important to consider the bifurcation caused by the journal bearing at the design stage of the rotor system. In this paper, nonlinear approximate modeling of fluid film force of a finite length model of the journal bearing is performed by discretizing the Reynolds equation using the finite difference method. Bifurcation analysis considering the influence of the bearing shape, such as oil inlet and groove, will be possible by using this model. In this model, the fluid film coefficients considering up to the third order are numerically calculated. In order to achieve compatibility between calculation cost and calculation accuracy, the relationship between the mesh number (mesh size) of the finite difference method and the accuracy of the fluid film coefficient is investigated, and an appropriate number of mesh is examined. Bifurcation analysis of the flexible rotating shaft system supported by the journal bearing is performed. The analytical results of the proposed model is compared with the analytical results of the fluid film force model using infinitesimally short journal bearing model applying the half-Sommerfeld boundary conditions, and its usefulness is validated.
