The paper presents some examples of simulation research carried out in view of large turbomachinery diagnostics. On the basis of computer simulations of some typical damages, such as “unbalanced” and hydrodynamic instability, it was possible to obtain the trajectories of the journal and the disc centre, as well as the amplitudes and the phase angles.
The paper refers to an example of two-point-supported rotor modelled using the Finite Element Method. The calculations were made on the basis of the complex elastodia-thermic model of the hydrodynamic slide bearing and also on the non-linear analysis of the system motion equations. The non-linear analysis made it possible to generate a characteristic vibration spectrum for every diagnostic relation. It refers especially to the computer simulations of the oil whirls and the oil whip, carried out for the various conditions of the rotor-machinery operation.