Title: Whirl flutter optimisation-based solution of twin turboprop aircraft using a full-span model
Authors: Čečrdle, Jiří
Citation: Applied and Computational Mechanics. 2017, vol. 11, no. 1, p. 1-18.
Issue Date: 2017
Publisher: University of West Bohemia
Document type: článek
URI: http://hdl.handle.net/11025/26133
ISSN: 1802-680X (Print)
2336-1182 (Online)
Keywords: vířivé chvění;model s plným rozsahem;optimalizace
Keywords in different language: whirl flutter;full-span model;optimisation
Abstract: parts as a propeller or a gas-turbine engine rotor. The proposed optimisation-based analytical procedure is used to determine the critical values of the engine attachment stiffness parameters for the preselected flutter speed. For the half-span model, two design variables are used. The objective function is defined as the minimization of the engine vibration mode frequency sum. Design constraints keep the engine frequency ratio and the flutter stability at the selected velocity. However, application of a full-span model is necessary in some cases. In this case, special models of both symmetric and antisymmetric engine vibrations and four design variables must be used. Design constraints maintain the pitch mode frequency ratio, the yaw mode frequency ratio and the critical mode frequency ratio. Critical modes are dependent on the relation between the rotational direction of both propellers (identical or inverse). A flutter design constraint is applied as well. The described methodology is demonstrated on the application example of a twin-engine commuter aircraft. Demonstrated cases include symmetrical revolutions of propellers for both identical and inverse directions of rotation, cases of single engine failure and single propeller feathering, and finally, cases of unsymmetrical revolutions including the reduced and increased revolutions of a single propeller, for both identical and inverse directions of rotation.
Rights: © 2017 University of West Bohemia. All rights reserved.
Appears in Collections:Volume 11, number 1 (2017)
Volume 11, number 1 (2017)

Files in This Item:
File Description SizeFormat 
Cecrdle.pdfPlný text2,72 MBAdobe PDFView/Open

Please use this identifier to cite or link to this item: http://hdl.handle.net/11025/26133

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.