Numerical Simulation of Compressible Flow Over a Deep Cavity Aerospace Engineering

106 Pages·2014·10.9 MB·English

by  Andre C. Marta

Numerical Simulation of Compressible Flow Over a
Deep Cavity
Pedro Guilherme Franco Escaleira Freitas
Thesis to obtain the Master of Science Degree in
Aerospace Engineering
Supervisor(s): Prof. José Carlos Fernandes Pereira
Examination Committee
Chairperson: Prof. Fernando José Parracho Lau
Supervisor: Prof. José Carlos Fernandes Pereira
Member of the Committee: Dr. José Manuel da Silva Chaves Ribeiro Pereira
June 2014
ii
Acknowledgments
The first group that I would like to thank is to my family for their unconditional support and love
throughtheseyearsinespeciallytomymother.
ThenIwouldliketothanktoprofessorJose´ CarlosPereirafortheopportunitytoworkatLaSEF
underhissupervision,corrections,supportandguidanceduringthiswork.
Thirdly I cannot forget some of the LaSEF members who are Duarte Albuquerque, doctor
PedroValenteandRodrigoTaveirafortheirhelpinthemostvariedthingssuchasproblemsinthe
Linuxsystemorinthesimulationsandevencodesharingtoimprovepost-processingtools.
FourthlytoJoa˜oMirandawhointroducedmetoOpenFOAMandsharedvaluableinformation
andknowledgeofthesoftware.
AndfinallytoprofessorAndre´ MartaforhiskindnessofsharingaLATEXtemplateaccordingto
theISTregulationsforaMasterorPhDthesis.
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iv
Resumo
O escoamento turbulento transo´nico sobre uma cavidade funda e´ analisado usando o software
OpenFOAM para LES (modelo de Smagorinsky) e RANS (modelos κ−ε e κ−ω) transiente e
comparadocomdadosexperimentaisecomputacionais. Aprincipalcaracter´ısticadascavidades
fundas e´ o campo sonoro ser muito intenso o que leva a problemas de fadiga e vibrac¸o˜es nas
estruturas. Portantotambe´mfoifeitaumaana´liseaumapeˆndicedecontroloparareduziroru´ıdo
emitido da cavidade. As simulac¸o˜es de LES, no geral, forneceram os melhores resultados de
acordo com os dados experimentais e computacionais. Por fim, a reduc¸a˜o de ru´ıdo foi obtida
comsucessousandoumarampanaparedeajusante.
Palavras-chave:
CavidadeFunda,Escoamentotranso´nico,LES,RANS,OpenFOAM,
ControloPassivo.
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Abstract
AtransonicturbulentflowoveradeepcavityisstudiedwiththeOpenFOAMcodeforLES(Smagorin-
skymodel)andunsteadyRANS(κ−εandκ−ωmodels)andcomparedwithavailableexperimen-
talandcomputationaldata. Themainfeatureofdeepcavitiesisthesoundfieldthatistoointense
that leading to fatigue and vibration issues on the structures. So it is also done a simulation on
a control device to reduce the emitted noise of the cavity. In general, LES simulations are in a
much better agreement with experimental and computational data. Finally, the noise reduction
wasachievedsuccessfullybyslantingtheaftwall.
Keywords:
DeepCavity,TransonicFlow,LES,RANS,OpenFOAM,PassiveControl.
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Contents
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Resumo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
ListofTables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
ListofFigures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi
1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 BasicPhysicsofSubsonic,TransonicandSupersonicCavityFlows . . . . . . . . . 3
1.2.1 OpenCavities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.2 ClosedCavities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2.3 TransitionalCavities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2.4 CavityClassificationBasedonGeometricalRelations . . . . . . . . . . . . 11
1.3 SimilarResonantFlows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3.1 EdgeToneFlow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3.2 ImpingingJet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3.3 JetScreech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.4 ExperimentalWorks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.5 NumericalWorks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.5.1 RANS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.5.2 LES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.5.3 DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.6 NoiseControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.7 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.8 OrganizationoftheDissertation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2 MathematicalandPhysicalModels 21
2.1 Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
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2.2 TurbulenceModels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.1 RANS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.2 LES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3 OpenFOAM 33
3.1 GeometryandMeshGeneration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.2 PhysicalPropertiesandTurbulenceModelChoice . . . . . . . . . . . . . . . . . . 35
3.3 SolversSpecification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.4 RunningtheSimulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4 DeepCavitySimulations 39
4.1 ComputationalDomain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.1.1 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.1.2 Meshes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.1.3 BoundaryConditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2 UpstreamBoundaryLayerPredictions . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.3 InstantaneousFlowField . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.3.1 MachNumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.3.2 CoherentStructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.3.3 Vorticity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.3.4 Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.4 PressureSpectralDensity,SoundPressureLevel . . . . . . . . . . . . . . . . . . . 51
4.5 TheVelocityField. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.5.1 RANSModelResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.5.2 LESModelResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.5.3 ComparisonBetweenRANSandLES . . . . . . . . . . . . . . . . . . . . . 70
4.6 CutGeometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.6.1 TheInfluenceatthedownstreamregion . . . . . . . . . . . . . . . . . . . . 72
5 Conclusions 75
Bibliography 83
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