Design optimization of the A320 engine inlet cowl Aerospace Engineering

110 Pages·2016·14.82 MB·English

by  Andre C. Marta

Design optimization of the A320 engine inlet cowl
Bruno Santos da Conceição
Thesis to obtain the Master of Science Degree in
Aerospace Engineering
Supervisors: Prof. Luís Filipe Galrão dos Reis
Prof. Vítor Manuel Rodrigues Anes
Examination Committee
Chairperson: Prof. Filipe Szolnoky Ramos Pinto Cunha
Supervisor: Prof. Luís Filipe Galrão dos Reis
Member of the Committee: Prof. Aurélio Lima Araújo
November 2016
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Acknowledgments
I would like to express my gratitude to Prof. Lu´ıs Reis and V´ıtor Anes for their support and recom-
mendations through the development of the Thesis. I would like to thank TAP Engines Engineering
department for their availability and for the opportunity of having direct contact with the components at
theirfacilities.
Iwouldliketoexpressmygratitudetomyparentsandgrandparentsfortheirsupportandfortheirmoti-
vationalspeecheswhenmostneeded. Iwouldliketothankmysisterforherwiseadviseswhendifficult
decisions had to be made. Finally, I would like to thank my girlfriend for having been so supportive,
patientandcomprehensivewhenlatenightworkhadtobedone.
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Resumo
Asaeronavesoperamemmeiosnosquaisosseuscomponentesesta˜osujeitosagrandesvariac¸o˜esde
pressa˜o e temperatura. Em estruturas como as nacelles dos motores, que sa˜o compostas por va´rios
componentes e materiais, tornam-se vis´ıveis alguns sinais de desgaste e corrosa˜o, originados pela
sua operac¸a˜o em ambientes como o acima descrito. Nestes casos, devem de ser tomadas medidas
correctivas. Ospaine´isacu´sticosdaentradadeardoAirbusA320/A321,apresentamalgunsproblemas
dedesgasteecorrosa˜onasdoublers dealum´ıniodasjuntas.
Porformaapoderdesenvolver-seumaacc¸a˜ocorrectivaaon´ıveldasjuntasdospaine´isacu´sticos,deve
serrealizadaumaana´lisedocomportamentomecaˆnicoedasforc¸asactuantesnasmesmas.
Nestatesedemestrado,foidesenvolvidaumametodologiaparaaana´lisedocomportamentomecaˆnico
das juntas dos paine´is acu´sticos com base em ferramentas, tais como, Dinaˆmica de Fluidos Com-
putacional (CFD), Me´todo dos Elementos Finitos (FEM) e Desenho Assistido por Computador (CAD).
A modelac¸a˜o da entrada de ar e dos seus componentes e´ feita atrave´s da utilizac¸a˜o do programa
Solidworks. A utilizac¸a˜o do programa de CFD, STAR CCM+, permitiu a determinac¸a˜o do carrega-
mentoaerodinaˆmicoaqueaentradadearesta´ sujeita. Aana´liseestruturaldoscomponentesdajunta
do painel acu´stico e´ realizada com uso das ferramentas de FEM, dispon´ıveis no programa ANSYS
Workbench. Todos os passos envolvidos nestas ana´lises sa˜o explicados e os resultados obtidos sa˜o
apresentados.
Palavras-chave:
Aeronave,entradadear,paine´isacu´sticos,carregamentoaerodinaˆmico,com-
portamentomecaˆnico,juntas.
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Abstract
Aircraftoperateinenvironmentsinwhichthecomponentsaresubjecttolargetemperatureandpressure
variations. In structures as the engine nacelles, composed by several components and materials, the
presence of wear and corrosion becomes noticeable, due to the their operation in environments as the
one foremost described. Corrective actions must be employed to the components which present this
kind of problems. The acoustic panels of the inlet cowl of the Airbus A320/A321, present corrosion
problemsonthealuminiumdoublersofthejoints.
Inordertodevelopacorrectiveactiontothejointoftheacousticpanels,theanalysisofthemechanical
behaviourandforcesactingonthejointmustbemade.
In this master’s thesis, a methodology involving Computational Fluid Dynamics (CFD), Finite Element
Method(FEM)andComputerAidedDesign(CAD)toolsisdevelopedinordertoanalysethemechanical
behaviouroftheacousticpanel’sjoint. Thegeometryoftheinletcowlandofitscomponentsismodelled
withtheuseofSolidworkssoftware. Thedeterminationoftheaerodynamicloadsactingontheinletcowl
ismadewiththeuseofCFDtools, withSTARCCM+software. Thestructuralanalysisofthemembers
of the joint of the acoustic panels is made with the use of FEM tools in ANSYS Workbench software.
Thestepsinvolvedintheanalysisareexplainedandtheresultsarepresented.
Keywords:
Aircraft,inletcowl,acousticpanels,aerodynamicloads,mechanicalbehaviour,joints.
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Contents
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Resumo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
ListofContents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
ListofTables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
ListofFigures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
AcronymsandNomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 ThesisOutline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Background 5
2.1 TurbofanEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 TheNacelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Aircraftnoise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.1 AircraftNoiseSources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2 NoiseReductionTechnology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3.3 TheAcousticLiner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 ComputationalFluidDynamics-Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4.1 GoverningEquationsofFluidFlow . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4.2 RANSEquationsandTurbulenceModels . . . . . . . . . . . . . . . . . . . . . . . 18
2.5 JointsandFasteners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.5.1 Comparisonbetweenmechanicallyfastenedandadhesivebondedjoints . . . . . 19
2.5.2 Fasteners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5.3 FastenedJointsFailureandPrevention . . . . . . . . . . . . . . . . . . . . . . . . 21
2.5.4 HoneycombSandwichTensileandShearProperties . . . . . . . . . . . . . . . . . 24
2.6 BoltedJointsinAnsysWorkbench . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.6.1 ModellingBolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.6.2 ModellingContactinJoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
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3 AerodynamicLoadsDetermination-CFDMethodology 27
3.1 CADModellingoftheA320/321NacelleInlet . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.2 SimulatedFlightConditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.3 CFDApproaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.1 Methodology1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.2 Methodology2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.4 TheCFDMethodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.4.1 ComputationalDomain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.4.2 GeneratedMesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.4.3 TheProblemPhysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.5 BoundaryConditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.5.1 SettingTheBoundaryConditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.5.2 TheFANBoundaryConditionCalculation . . . . . . . . . . . . . . . . . . . . . . . 37
3.6 MethodologySuitability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.7 CFDResultsandDiscussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4 FEMMethodology-AnalysisoftheJointsoftheAcousticPanel 51
4.1 InletCowlComponents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4.1.1 TheAcousticPanelJoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.2 PreparingtheFEMSimulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.2.1 AerodynamicLoad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.2.2 GeometryandGeometryImportation . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.3 MaterialsandProperties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.2.4 ContactBetweenComponents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.2.5 DefiningtheMesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.3 DeterminationoftheCriticalLoadCondition . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.3.1 ModelConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.4 ApproachtoAnalysetheAcousticPanelJoint . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.4.1 ModelSimplifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.5 AnalysisofthefastenersoftheJoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
4.5.1 ComponentsContactandMeshRefinement . . . . . . . . . . . . . . . . . . . . . 64
4.5.2 ConvergenceAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.5.3 ResultandDiscussionoftheFastenersAnalysis . . . . . . . . . . . . . . . . . . . 66
4.6 AnalysisoftheInterfacebetweenInternalHoneycombCoreandInternalDoubler . . . . . 70
4.6.1 ComponentsContactandMeshRefinement . . . . . . . . . . . . . . . . . . . . . 70
4.6.2 ConvergenceAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.7 ResultsandDiscussionoftheJointsAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.7.1 TheFlatwiseTensileStrength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.7.2 TheShearStress. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
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