Application of model updating techniques to turbomachinery rotor components

Abstract

Model updating techniques are commonly used to improve simulation accuracy. Experimental data of component testing under laboratory conditions are normally used to improve analytical predictions of that component under operational conditions. In this study, we have applied these techniques to the dynamics of turbomachinery components. Dynamics of turbomachinery rotor components are normally analysed assuming perfect cyclic symmetry of the basis sector (one blade and its corresponding part of the disc) and this sector is mechanically the same in every angular position. However, the manufacturing process introduces small differences among sectors (mistuning) and changes the global dynamic behaviour. There are several analytical approaches in the literature to model these differences with reduced order models of the whole rotor that include the frequency differences among sectors, which can be obtained experimentally in a component test. Several approaches in the literature use experimental results from a test with a particular set-up in order to obtain the inputs for the models. The approach proposed in this article is just to perform a standard modal test that generates the input for model updating and to extract from the updated model the required input for representing the mistuning phenomena in turbomachinery rotor components.