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Aero‐elastic bearing effects on rotor dynamics: a numerical analysis
Author(s) -
Barzem L.,
BouSaid B.,
Rocchi J.,
Grau G.
Publication year - 2013
Publication title -
lubrication science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.632
H-Index - 36
eISSN - 1557-6833
pISSN - 0954-0075
DOI - 10.1002/ls.1218
Subject(s) - airfoil , mechanics , dissipation , nonlinear system , aeroelasticity , instability , bearing (navigation) , finite element method , classical mechanics , deflection (physics) , turbulence , physics , structural engineering , engineering , aerodynamics , quantum mechanics , astronomy , thermodynamics
In recent decades, numerous models for airfoil bearings have been developed. However, these models are not sufficiently accurate for rotor response prediction in the presence of nonlinearities. It is essential to control the instabilities due to the nonlinear behaviour in order to quantify the energy dissipation in the bearings. By means of a variational approach, the flexible structure is modelled as a thin medium subject to a compressible fluid pressure, under isothermal conditions, in the laminar and turbulent regimes. The model is constructed using the finite element method for the structure response. Internal dry friction is taken into account with Coulomb's law and an updated Lagrangian method. The structure model is coupled with Reynolds equation to obtain the rotor displacement, using the equations of motion for the complete mechanical system. This work is performed to show the influence of the thin structure approach on the rotor behaviour and the field pressure. The link between deflection of the bumps and dry friction is established. The structure buckling is increased by both friction between the sheets and energy dissipation. A second objective is to identify the subsynchronous frequencies in order to establish the relevance of the new airfoil model for nonlinear and instability investigations. Copyright © 2012 John Wiley & Sons, Ltd.