Nonlinear airfoil torsional response induced by separated flows
Autor(a) principal: | |
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Data de Publicação: | 2015 |
Outros Autores: | , |
Tipo de documento: | Artigo de conferência |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://hdl.handle.net/11449/167926 |
Resumo: | Stall-induced vibrations are nonlinear aeroelastic phenomena. Helicopter rotors, wind turbine blades, or other rotating components interacting with an airow may vibrate in stall condition. Despite a signiffcant effort to model the aerodynamics associated to the stall or separated flows, nonlinear aeroelastic behavior prediction and analysis in such flow regime remain a formidable challenge. Another source of nonlinearity with inuence to aeroelastic response may be associated to the structure dynamic response. The combi- nation of both separated flow aerodynamics and structural nonlinearities lead to complex dynamics, for instance, bifurcations and chaos. The purpose of this work is to present the analysis of stall-induced vibrations, or separated flow effects, of an airfoil in pitching when concentrated nonlinearities are associated to the structural dynamics. Limit cycles oscillations at higher angles of attack and complex nonlinear features are analyzed for different representations for concentrated restoring pitching moment. The pitching-only typical section dynamics is coupled with an unsteady aerodynamic model based on Beddoes- Leishmann semi-empirical approach to produce the proper framework for gathering time series of aeroelastic responses. The analyses are performed by checking the amplitude of the aeroelastic responses in limit cycle oscillations. Evolutions on limit cycles amplitudes are used to reveal bifurcation points also admitting Mach numbers range up to 0.7, thereby providing important information to assess, characterize, and qualify the nonlinear behavior associated with combinations of different forms to represent concentrated pitching spring of the typical section. The concentrate structural nonlinearities under investigation are the hardening and softening cubic, free-play, and hysteresis. Results reinforce that oscillations under the effects of stall are mostly determined by the flow ffeld. The structural nonlinear- ities are most relevant at lower airspeeds. Different bifurcations can be observed in Mach evolutions of LCOs, in which structural effects can be important to delay its onset. |
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Nonlinear airfoil torsional response induced by separated flowsStall-induced vibrations are nonlinear aeroelastic phenomena. Helicopter rotors, wind turbine blades, or other rotating components interacting with an airow may vibrate in stall condition. Despite a signiffcant effort to model the aerodynamics associated to the stall or separated flows, nonlinear aeroelastic behavior prediction and analysis in such flow regime remain a formidable challenge. Another source of nonlinearity with inuence to aeroelastic response may be associated to the structure dynamic response. The combi- nation of both separated flow aerodynamics and structural nonlinearities lead to complex dynamics, for instance, bifurcations and chaos. The purpose of this work is to present the analysis of stall-induced vibrations, or separated flow effects, of an airfoil in pitching when concentrated nonlinearities are associated to the structural dynamics. Limit cycles oscillations at higher angles of attack and complex nonlinear features are analyzed for different representations for concentrated restoring pitching moment. The pitching-only typical section dynamics is coupled with an unsteady aerodynamic model based on Beddoes- Leishmann semi-empirical approach to produce the proper framework for gathering time series of aeroelastic responses. The analyses are performed by checking the amplitude of the aeroelastic responses in limit cycle oscillations. Evolutions on limit cycles amplitudes are used to reveal bifurcation points also admitting Mach numbers range up to 0.7, thereby providing important information to assess, characterize, and qualify the nonlinear behavior associated with combinations of different forms to represent concentrated pitching spring of the typical section. The concentrate structural nonlinearities under investigation are the hardening and softening cubic, free-play, and hysteresis. Results reinforce that oscillations under the effects of stall are mostly determined by the flow ffeld. The structural nonlinear- ities are most relevant at lower airspeeds. Different bifurcations can be observed in Mach evolutions of LCOs, in which structural effects can be important to delay its onset.Engineering School of São Carlos, University of São PauloUNESP,São Paulo State University (UNESP)UNESP,São Paulo State University (UNESP)Universidade de São Paulo (USP)Universidade Estadual Paulista (Unesp)Pereira, Daniel A.Vasconcellos, Rui M. G. [UNESP]Marques, Flávio D.2018-12-11T16:38:53Z2018-12-11T16:38:53Z2015-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObject56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference.http://hdl.handle.net/11449/1679262-s2.0-8493783756603479922475174420000-0001-7288-5408Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPeng56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conferenceinfo:eu-repo/semantics/openAccess2021-10-23T21:47:02Zoai:repositorio.unesp.br:11449/167926Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:47:10.356423Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Nonlinear airfoil torsional response induced by separated flows |
title |
Nonlinear airfoil torsional response induced by separated flows |
spellingShingle |
Nonlinear airfoil torsional response induced by separated flows Pereira, Daniel A. |
title_short |
Nonlinear airfoil torsional response induced by separated flows |
title_full |
Nonlinear airfoil torsional response induced by separated flows |
title_fullStr |
Nonlinear airfoil torsional response induced by separated flows |
title_full_unstemmed |
Nonlinear airfoil torsional response induced by separated flows |
title_sort |
Nonlinear airfoil torsional response induced by separated flows |
author |
Pereira, Daniel A. |
author_facet |
Pereira, Daniel A. Vasconcellos, Rui M. G. [UNESP] Marques, Flávio D. |
author_role |
author |
author2 |
Vasconcellos, Rui M. G. [UNESP] Marques, Flávio D. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Universidade de São Paulo (USP) Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Pereira, Daniel A. Vasconcellos, Rui M. G. [UNESP] Marques, Flávio D. |
description |
Stall-induced vibrations are nonlinear aeroelastic phenomena. Helicopter rotors, wind turbine blades, or other rotating components interacting with an airow may vibrate in stall condition. Despite a signiffcant effort to model the aerodynamics associated to the stall or separated flows, nonlinear aeroelastic behavior prediction and analysis in such flow regime remain a formidable challenge. Another source of nonlinearity with inuence to aeroelastic response may be associated to the structure dynamic response. The combi- nation of both separated flow aerodynamics and structural nonlinearities lead to complex dynamics, for instance, bifurcations and chaos. The purpose of this work is to present the analysis of stall-induced vibrations, or separated flow effects, of an airfoil in pitching when concentrated nonlinearities are associated to the structural dynamics. Limit cycles oscillations at higher angles of attack and complex nonlinear features are analyzed for different representations for concentrated restoring pitching moment. The pitching-only typical section dynamics is coupled with an unsteady aerodynamic model based on Beddoes- Leishmann semi-empirical approach to produce the proper framework for gathering time series of aeroelastic responses. The analyses are performed by checking the amplitude of the aeroelastic responses in limit cycle oscillations. Evolutions on limit cycles amplitudes are used to reveal bifurcation points also admitting Mach numbers range up to 0.7, thereby providing important information to assess, characterize, and qualify the nonlinear behavior associated with combinations of different forms to represent concentrated pitching spring of the typical section. The concentrate structural nonlinearities under investigation are the hardening and softening cubic, free-play, and hysteresis. Results reinforce that oscillations under the effects of stall are mostly determined by the flow ffeld. The structural nonlinear- ities are most relevant at lower airspeeds. Different bifurcations can be observed in Mach evolutions of LCOs, in which structural effects can be important to delay its onset. |
publishDate |
2015 |
dc.date.none.fl_str_mv |
2015-01-01 2018-12-11T16:38:53Z 2018-12-11T16:38:53Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/conferenceObject |
format |
conferenceObject |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. http://hdl.handle.net/11449/167926 2-s2.0-84937837566 0347992247517442 0000-0001-7288-5408 |
identifier_str_mv |
56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. 2-s2.0-84937837566 0347992247517442 0000-0001-7288-5408 |
url |
http://hdl.handle.net/11449/167926 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128562882936832 |