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Whirl flutter analysis of prop-rotors using unsteady aerodynamics reduced-order models

Published online by Cambridge University Press:  03 February 2016

M. Gennaretti  and
L. Greco
M. Gennaretti
Affiliation:
Department of Mechanical and Industrial Engineering, University Roma Tre, Rome, Italy
L. Greco
Affiliation:
INSEAN, Italian Ship Model Basin, Rome, Italy
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Abstract

The prediction of this aeroelastic phenomenon is an urgent need of the designer and requires devoted numerical tools. This work examines the influence of the accuracy of the aerodynamic modelling on whirl flutter analysis, with particular attention to those models that can conveniently be applied to preliminary design and control purposes. Considering a simple pylon/prop-rotor structure, the aeroelastic instability boundaries are identified by 2D quasi-steady and 2D unsteady aerodynamics theories, along with a 3D unsteady, potential flow BEM solver. A methodology for deriving reduced-order models from unsteady aerodynamic solutions is used. The numerical investigation highlights that the accuracy of the aerodynamic solver included in the analysis may be of crucial importance. The use of 2D aerodynamic models does not always guarantee conservative stability predictions, and this is particularly true for three-bladed rotors where a fully 3D unsteady solver coupled with a wake alignment algorithm seems to be necessary.

Type
Research Article
Information
The Aeronautical Journal , Volume 112 , Issue 1131 , May 2008 , pp. 261 - 270
Copyright
Copyright © Royal Aeronautical Society 2008 

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