The non-linear analysis of the effect of support construction properties on the dynamic properties of multi-support rotor systems

The paper reports on the course of simulation research of large rotor machines (200 MW power turbine sets) carried out at the Institute of Fluid-Flow Machinery, Polish Academy of Sciences (IFFM PAS). The investigations draw on a non-linear theoretical model and a developed computer code. The paper presents the main assumptions of this model and examples of its experimental verification. An attempt is made to classify the hydrodynamic instability of the system, in a diagnostic manner. The analysis of dynamic properties of a 200 MW turbo-set is concentrated on two selected problems, the first of which is the effect of thermoelastic deformation of the bearing bushes on the lateral forced vibration of the rotor line system. The simulation research is conducted on the basis of a three-dimensional elastodiathermal model of the bearing nodes. This enables the modelling of complex processes of heat transfer in the bearing, as well as the validation of arbitrary methods of fixing and action areas of the initial clamping forces. The second problem is the analysis, based on the finite element method, of dynamic properties of the LP casing at the fixing points of the bearing bushes. (C) 1997 Academic Press Limited.