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Modelling Turbulence in Engineering and the Environment: Rational Alternative Routes to Closure PDF

535 Pages·2023·71.119 MB·English
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MODELLING TURBULENCE IN ENGINEERING AND THE ENVIRONMENT RationalAlternativeRoutestoClosure Modelling transport and mixing by turbulence in complex flows are huge challenges for computational fluid dynamics (CFD). This highly readable book introduces readers to modelling levels that respect the physical complexity of turbulent flows. It examines thehierarchyofReynolds-averagedNavier–Stokes(RANS)closuresinvarioussituations rangingfromfundamentalflowstothree-dimensionalindustrialandenvironmentalappli- cations.Thegeneralsecond-momentclosureissimplifiedtolineareddy-viscositymodels, demonstratinghowtoassesstheapplicabilityofsimplerschemesandtheconditionsunder whichtheygivesatisfactorypredictions. Theprincipalchangesforthesecondeditionreflecttheimpactofcomputingpower:a newchapterdevotedtounsteadyRANSandanotheronhowlarge-eddysimulation,LES, andRANSstrategiescanbeeffectivelycombinedforparticularapplications. This book will remain the standard for those in industry and academia seeking expert guidanceonthemodellingoptionsavailable,andforgraduatestudentsinphysics,applied mathematicsandengineeringenteringtheworldofturbulentflowCFD. KEMAL HANJALIC´ isProfessorEmeritusattheDelftUniversityofTechnologyandan internationalfellowoftheUK’sRoyalAcademyofEngineeringandtheRussianAcademy ofScience.Hisinnovativeandsustainedcontributionstoturbulence-modeldevelopment, includingheattransferandenvironmentalflows,havebeenrecognizedbytheMaxPlanck andNusselt–ReynoldsResearchPrizes. BRIAN LAUNDER, Emeritus Professor at the University of Manchester, has enjoyed morethanahalf-centuryofturbulence-modellingprojectswithhisco-author.Widelycited for his two-equation eddy-viscosity modelling, his main focus has been stress-transport andnon-lineareddy-viscosityclosures.HewaselectedFRSandFREngforhisturbulence researchwithhonorarydoctoratesfromthreeEuropeanuniversities. Published online by Cambridge University Press Published online by Cambridge University Press MODELLING TURBULENCE IN ENGINEERING AND THE ENVIRONMENT Rational Alternative Routes to Closure Second Edition ´ KEMAL HANJALIC and BRIAN LAUNDER DelftUniversityofTechnology UniversityofManchester Chapter10co-authoredwith ALISTAIR J. REVELL UniversityofManchester Published online by Cambridge University Press UniversityPrintingHouse,CambridgeCB28BS,UnitedKingdom OneLibertyPlaza,20thFloor,NewYork,NY10006,USA 477WilliamstownRoad,PortMelbourne,VIC3207,Australia 314–321,3rdFloor,Plot3,SplendorForum,JasolaDistrictCentre,NewDelhi–110025,India 103PenangRoad,#05–06/07,VisioncrestCommercial,Singapore238467 CambridgeUniversityPressispartoftheUniversityofCambridge. ItfurtherstheUniversity’smissionbydisseminatingknowledgeinthepursuitof education,learning,andresearchatthehighestinternationallevelsofexcellence. www.cambridge.org Informationonthistitle:www.cambridge.org/9781108835060 DOI:10.1017/9781108875400 ©KemalHanjalic´andBrianLaunder2011,2023 Thispublicationisincopyright.Subjecttostatutoryexception andtotheprovisionsofrelevantcollectivelicensingagreements, noreproductionofanypartmaytakeplacewithoutthewritten permissionofCambridgeUniversityPress. Firstpublished2011 Secondedition2023 PrintedintheUnitedKingdombyTJBooksLimited,PadstowCornwall AcataloguerecordforthispublicationisavailablefromtheBritishLibrary. LibraryofCongressCataloging-in-PublicationData Names:Hanjalic´,Kemal,author.|Launder,B.E.(BrianEdward),author. Title:Modellingturbulenceinengineeringandtheenvironment:rationalalternativeroutestoclosure/ KemalHanjalic´,TechnischeUniversiteitDelft,TheNetherlandsandBrianLaunder,Universityof Manchester;Chapter10co-authoredbyAlistairRevell,UniversityofManchester. Description:Secondedition.|Cambridge,UnitedKingdom;NewYork,NY:CambridgeUniversity Press,2022.|Includesbibliographicalreferencesandindex. Identifiers:LCCN2021059599(print)|LCCN2021059600(ebook)|ISBN9781108835060(hardback)| ISBN9781108875400(ebook) Subjects:LCSH:Turbulence–Mathematicalmodels.|BISAC:SCIENCE/Mechanics/Fluids Classification:LCCTA357.5.T87H3672022(print)|LCCTA357.5.T87(ebook)|DDC 532/.0527–dc23/eng/20220217 LCrecordavailableathttps://lccn.loc.gov/2021059599 LCebookrecordavailableathttps://lccn.loc.gov/2021059600 ISBN978-1-108-83506-0Hardback CambridgeUniversityPresshasnoresponsibilityforthepersistenceoraccuracyof URLsforexternalorthird-partyinternetwebsitesreferredtointhispublication anddoesnotguaranteethatanycontentonsuchwebsitesis,orwillremain, accurateorappropriate. Published online by Cambridge University Press Contents Preface pageix PrefacetotheFirstEdition xiii PrincipalNomenclature xvii 1 Introduction 1 1.1 Thefactofturbulentflow 1 1.2 Broadoptionsinmodelling 2 1.3 A preview of the mean-strain generation processes in the stress-transportequation 5 1.4 Some consequences of the no-slip boundary condition at a wall 9 1.5 Sequencingofthematerial 11 2 Theexactequations 13 2.1 Theunderpinningconservationequations 13 2.2 TheReynoldsequations 15 2.3 Thesecond-momentequations 22 3 Characterizationofstressandfluxdynamics:elementsrequired formodelling 33 3.1 Introduction 33 3.2 Energyflowprocessesinturbulence 33 3.3 Thespectralcharacterofturbulence 38 3.4 Theε-equation 43 3.5 Transport equation for the mean-square scalar variance, θ2 46 3.6 Transportequationfordissipationofscalarvariance,εθθ 48 3.7 Turbulenceanisotropy,invariantsandrealizability 50 v Published online by Cambridge University Press vi Contents 4 Approachestoclosure 59 4.1 Generalremarksandbasicguidelines 59 4.2 Pressureinteractions,Φij andΦθj:thePoissonequation 62 4.3 The basic second-moment closure for high-Re flow t regions 66 4.4 Pressure-strainmodelsfromtensorexpansion 84 4.5 Turbulenceaffectedbyforcefields 111 4.6 Modellingthetriplemoments 131 5 Modellingthescale-determiningequations 140 5.1 Theenergydissipationrate,ε 140 5.2 Otherscale-determiningequations 152 5.3 Multi-scaleapproaches 157 5.4 Determiningεθθ,thedissipationrateofθ2 163 6 ModellingintheimmediatewallvicinityandatlowRe 167 t 6.1 The nature of viscous and wall effects: options for modelling 167 6.2 Thestructureofthenear-wallsublayer 170 6.3 Wallintegration(WIN)schemes 185 6.4 Illustrationoftheperformanceoftwonear-wallmodels 208 6.5 Ellipticrelaxationconcept 222 7 Simplifiedschemes 233 7.1 Rationaleandorganization 233 7.2 Reducedtransport-equationmodels 234 7.3 Algebraictruncationsofthesecond-momentequations 239 7.4 Lineareddy-viscositymodels 261 8 Wallfunctions 293 8.1 Earlyproposals 293 8.2 Towards a generalization of the wall-function concept: preliminaries 299 8.3 Analyticalwallfunctions(AWFs) 302 8.4 AsimplifiedAWF(SAWF) 312 8.5 Blendedwalltreatment(BWT) 319 8.6 Numericalwallfunctions(NWFs) 327 9 RANSmodellingofunsteadyflows(URANS) 332 9.1 Feasibility of URANS for inherently unsteady turbulent flows 332 Published online by Cambridge University Press Contents vii 9.2 Mathematicalformalism 334 9.3 The role of the URANS model: EVM versus RSM in flow overacylinder 337 9.4 URANS modelling of swirling flows and vortex precessing 348 9.5 CapabilitiesofEVMsandASM/AFMswithinURANS 353 10 HybridRANS-LES(HRL) 371 Co-authoredwithAlistairJ.Revell 10.1 Introductionandoverview 371 10.2 Large-eddysimulation 381 10.3 Theclassificationofhybridmethods 396 10.4 BulkzonalmodelsandembeddedLES 402 10.5 Wall-modelledLES 406 10.6 Seamlessmethods 426 10.7 HybridRANS-LESmodels:summaryandoutlook 459 References 464 Index 498 Published online by Cambridge University Press Published online by Cambridge University Press Preface Over the decade since the first edition of Modelling Turbulence in Engineering and the Environment made its appearance, the wider topic of computational fluid dynamics–orCFDasitisnowuniversallyknown–hasbecomeevenmorefirmly establishedastheroutetoresolvingimportantandpossiblychallengingquestions of fluid motion in the turbulent flow regime. As the reader may judge from the Preface to that first edition (which follows), our view was that the progressive shift, then underway, from using the Reynolds-averaged Navier–Stokes (RANS) equationsasthebasisforaccountingforturbulenttransport(so-calledRANSmod- elling)tolarge-eddysimulation(LES)wasnotassuredlythepreferredpracticefor manyapplications. The notion that, to improve the reliability of one’s CFD computations, one needed to upgrade the modelling strategy from a RANS-based closure to LES largely arose from the presumption that RANS-based modelling was invariably associatedwiththeuseofalineareddy-viscosityapproximation.Thatpresumption we emphatically rejected. Our emphasis in the first edition was rather at a closure level where turbulent momentum, heat and mass fluxes were found not from such quasi-laminarconstitutiveconceptsbutratherbyapproximationoftheirowntrans- port equations, a path formally known as ‘second-moment closure’. Indeed, the subheadingtothebook’stitlewasSecond-MomentRoutestoClosure.Thisoverall philosophyisonethatweretaininthepresentedition,though,forreasonsthatwill shortlybecomeclear,thesubtitlehasbeenchangedtorecognizethebroaderrange ofmodellingnowincluded. Itisnotarguedthatsecond-momentclosureisalwaysthebestRANSapproach to follow, however. In simple shear flows where turbulence transport is small, second-momentclosuresamounttowhatistantamounttoaneddy-viscositymodel (EVM) of turbulence. There are then clear advantages to making simplifications to the physical model in order to achieve major savings in computational time, whether from solving fewer equations or from faster rates of convergence – or, ix https://doi.org/10.1017/9781108875400.001 Published online by Cambridge University Press

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