Session: 22-02 Compressor Aerodamping, Forced Response, and Mistuning

Paper Number: 152790

Improved Strain-Energy Based Mistuning Models - Part II: Understanding the Mistuned Blade Response for a Non-Isolated Family of Modes 

The second part of the two-part paper describes the impact of the improved strain energy-based model on the mistuned blade response of a non-isolated mode family. An improvement to the FMM method, this paper concentrates on coupling aerodynamic and structural dynamics into the mistuning model and incorporating a strain energy parameter that can help improve the accuracy of the mistuned prediction, especially in the "veering" region. One gap in the literature is the absence of a robust strain energy-based model, which can help improve the accuracy, particularly for cases in which the system mode family is not isolated, i.e., the mode family lies in the veering region, which in turn leads to a significant amount of strain energy in the disk. The current paper extends part I of this study and describes in detail the impact of modelling a different strain energy at every ND and validates the non-dimensional mistuning parameters against experimental data. The paper also describes the impact of different mistuning models on the mistuning amplification factor that includes the impact of system mode frequencies for the Purdue rotor. The key conclusions are: 1) The improved strain energy formulations lead to a significant improvement in the mistuning amplification factor for a non-isolated mode family and help couple the physics better in addition to better predictions for a non-isolated family of modes. 2) Perturbing the system mode frequency of a single ND has a significant impact on the mistuning amplification factor and is dependent on the mistuning model of choice.

Keywords: Compressor, Forced Response, Multi-Row, Mistuning, FMM, CMM, Disc Modes, Sidebands

 

Presenting Author: Shreyas Hegde Pratt&Whitney

Presenting Author Biography: Shreyas is a senior engineer, compressor system aerodynamics at Pratt&Whitney

Authors:

Shreyas Hegde Pratt&Whitney
Robert Kielb Duke University