A Methodology for The Appropriation And The Isolation of Nodal Diameter Modes in Cyclic Symmetric Structures

This paper presents a methodology enabling the appropriation and the isolation of a chosen nodal diameter modes in cyclic symmetric structures. In particular, a study about the minimum number and the optimized location of the excitation sources required in laboratory conditions to isolate a specific nodal diameter mode is conducted. This work includes a theoretical approach based on energy concepts. It is followed by the numerical and experimental validations on a stator stage of an axial compressor. The concept of modal appropriation is investigated here as the first step of the calibration procedure before engine tests.