Session: 28-02 Mistuning: Simulations & Experiments

Paper Number: 103185

103185 - Mistuning Sensitivity of a Fan Bladed-Disk With Geometrical Nonlinearities 

To decrease their environmental impact, the fan of turboengines tends to have a larger diameter while maintaining a slender profile. This design leads to more pronounced geometrical nonlinear effects. Computing the frequency forced response of such structures is complicated due to the size of their associated finite element model. Classical substructuring approaches are no longer efficient to reduce the size of the problem as all the nodes of the system are nonlinear and must be kept as master nodes. Different reduction methodologies have been defined in the past decades to tackle such nonlinear systems. One recent approach is called the Direct Normal Form, which extends the theory of normal form to finite element models. This methodology is here applied to a single blade model. Based on the assumption of a fairly rigid disk and on the nonlinear nodal diameters coupling, the reduced model of the sector is extended to create a full cyclic system reduced-order model. Such a procedure allows to perform, for instance, fast parametric studies.  The purpose of this paper is to study the sensitivity of the random mistuning on an Open Rotor system. While it is well-known that for linear bladed-disk, random mistuning modifies the level of vibration and thus has an overall detrimental effect on turbomachinery, this paper will show that the geometric nonlinearities allow to mitigate this effect.

Presenting Author: Samuel Quaegebeur Ecole Centrale de Lyon

Presenting Author Biography: After obtaining a master in McGill University, I got a PhD in Ecole Centrale de Lyon.

Authors:

Samuel Quaegebeur Ecole Centrale de Lyon
Fabrice Thouverez Ecole Centrale de Lyon