Direct and Large-Eddy Simulation VII ERCOFTAC SERIES VOLUME13 SeriesEditors R.V.A.Oliemans,ChairmanERCOFTAC, DelftUniversityofTechnology,Delft,TheNetherlands W.Rodi,DeputyChairmanERCOFTAC, UniversitätKarlsruhe,Karlsruhe,Germany AimsandScopeoftheSeries ERCOFTAC (European Research Community on Flow, Turbulence and Combustion) was founded as an international association with scientific objectives in 1988. ERCOFTAC strongly promotes joint efforts of European research institutes and industries that are active in the field of flow, turbulence and combustion, in order to enhancetheexchangeoftechnicalandscientificinformationonfundamentalandapplied researchanddesign.Eachyear,ERCOFTACorganizesseveralmeetingsintheformof workshops, conferences and summerschools, where ERCOFTAC members and other researchersmeetandexchangeinformation. TheERCOFTACSeries willpublish theproceedings of ERCOFTACmeetings, which coverallaspectsoffluidmechanics.Theserieswillcompriseproceedingsofconferences andworkshops,andoftextbookspresentingthematerialtaughtatsummerschools. The series covers the entire domain of fluid mechanics, which includes physical modelling, computational fluid dynamics including grid generation and turbulence modelling, measuring-techniques, flow visualization as applied to industrial flows, aerodynamics, combustion, geophysical and environmental flows, hydraulics, multi- phase flows, non-Newtonian flows, astrophysical flows, laminar, turbulent and transitionalflows. Forothertitlespublishedinthisseries,goto http://www.springer.com/series/5934 Direct and Large-Eddy Simulation VII Proceedings of the Seventh International ERCOFTAC Workshop on Direct and Large-Eddy Simulation, held at the University of Trieste, September 8–10, 2008 Editedby Vincenzo Armenio Universitàdi Trieste,Italy Bernard Geurts UniversityofTwente, Enschede, TheNetherlands and JochenFröhlich TechnicalUniversityofDresden, Germany 123 Editors Prof.Dr.-Ing.JochenFröhlich Dr.VincenzoArmenio InstituteofFluidMechanics UniversitàdiTrieste TechnicalUniversityofDresden Dipto.IngegneriaCivilee George-Bähr-Str.3c Ambientale 01062Dresden ViaValerio Germany 34127Trieste [email protected] Italy [email protected] Prof.BernardGeurts UniversityofTwente Fac.MathematicalSciences 7500AEEnschede TheNetherlands [email protected] [email protected] ISSN1382-4309 ISBN978-90-481-3651-3 e-ISBN978-90-481-3652-0 DOI10.1007/978-90-481-3652-0 SpringerDordrechtHeidelbergLondonNewYork LibraryofCongressControlNumber:2010922449 (cid:2)c SpringerScience+BusinessMediaB.V.2010 Nopartofthisworkmaybereproduced,storedinaretrievalsystem,ortransmittedinanyformorby anymeans,electronic,mechanical,photocopying,microfilming,recordingorotherwise,withoutwritten permissionfromthePublisher,withtheexceptionofanymaterialsuppliedspecificallyforthepurpose ofbeingenteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthework. Coverdesign:eStudioCalamarS.L. Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Preface In an era of continuously increasing computer power and increasing quality of algorithms and software Direct Numerical Simulations and Large Eddy Simulationsreceivecontinuouslyincreasinginterestandfacewidespreadusee. Nevertheless,developmentsofarestillneededandperformedbyresearchersin various directions.The ERCOFTAC series of workshopson Direct and Large Eddy Simulation organized since 1994 by various people reflect this activity and serve as catalyst to stimulate scientific exchange on this topic. During September 8–102007,the seventhworkshopofthis serieswasheld inTrieste, Italy. As the earlier workshops it aimed at establishing the state-of-art in turbulence modelling andnumericalmethodologiesofDirect andLargeEddy Simulation as well as their use in fundamental research and applications. Six plenary sessions, 16 parallel sessions and 2 poster sessions have been run during the three days. The nine keynote lectures have dealt with different fields of fundamen- tal, industrial and environmental fluid mechanics. Prof. S. Pope (Cornell University, USA) has discussed recent modelling techniques (LES/FDF) for reacting flows, like flames in combustors, and new methodologies to treat the transport of scalars in the flow field. Prof. G. Pedrizzetti (University of Trieste, Italy) has shown recent numerical results of the unsteady flow field within the left ventricular, and comparison with data obtained in real cases by means of eco-Doppler analysis. Prof. C. Meneveau’s talk (Johns Hopkins University, USA) has dealt with LES modelling of environmental fluid me- chanics, discussing large scale LES of pollen dispersion in the atmosphere, andcomparisonbetweennumericaland fielddata.Prof.U. Piomelli(Queen’s University,Canada)hasgivenasummaryofthestate-of-artofwall-modelling techniques within the LES framework for high Reynolds number flows. Prof. S.Elghobashi(UCIrvine,USA)hasdiscussedLagrangiantechniquesformul- tiphase flows, focussing on new formulations of the particle motion equation andontwo-waycouplingbetweenthe Eulerianfieldandthe Lagrangiantech- niques. Prof. R. Verzicco (University of Rome, Tor Vergata,Italy) has shown recent results regarding natural convection in confined flows, aimed at ex- plaining disagreements among experimental data and numerical simulations. Prof. T. Hughes (University of Texas at Austin, USA) has discussed a novel approach to LES methodology, based on the multi-scale methodology. Two VI Preface sets of equations are considered, one for the large scales of motion and one forthe smallones.Results ofsimulationsonsimple validationcasesprovethe reliability of the technique. This methodology is far from the classical ones wherethesmallscalesofmotionsareparameterizedinastatisticalsenseusing a SGS model, ant it can be a good alternative to classic SGS techniques in cases of very complex-physics flows, where the direct knowledge of the small scales of motion is required. Prof. R. Friedrich (TU Munich, Germany) has discussed recent results of boundary layer dynamics in compressible flows, considering both subsonic and supersonic conditions. Finally, Dr. Flohr (Al- stom, Switzerland) has discussed results of high-Reynolds number large eddy simulationofgasturbinecombustors,givinganiceexampleofthesuperiority of the LES approachwhen compared to classing RANS methodologies. The regular sessions focussed on different topics. Environmental applica- tionswereshown,fromthelaboratory-scalenumericalexperimentscarriedout using both DNS and wall-resolving LES to applicative full-scale simulations carriedout through LES with wall-layermodels. Also fundamental studies of turbulence were discussed in a wide range of basic fields, from the canonical boundary layer to the isotropic turbulence. A session of compressible flows rangedfrombasicstudiesofinteractionbetweencompressibleeffectsandtur- bulencetowall-layermodellingforLESofcompressibleflows.Themultiphase flowssessioncoveredclassicalparticleladenflowanalysesaswellasthestudy of bubbles and featured state-of-art approaches where the dispersed phase is treated as an ensemble of finite-size particles. The session on aerodynamics and wakes treated classical aerodynamics problems, approached through the useofstate-of-the-artnumericaltechniquesandSGSmodels.Also,morechal- lenging problems where discussed such as turbulent wakes affected by strat- ification. The session on evolution of active scalars, comprised both reactive flows(forcombustionproblems)andclassicalnaturalconvectionproblems.A sessionofanalysisandquantificationofmodellingerrorsinLESdiscussedand rigorouslyquantifiedthenumericalerrorsassociatedwiththeuseofloworder numericalschemesinconjunctionwithSGSmodels.Finally,intheLESmod- elling session new ideas for roust and accurate SGS models were discussed. The number of oral presentation was 74. Short presentations of 15 posters completed the program.The number of participants was about 120,of which 37 were undergraduate and graduate students. As a whole, based on the scientific contributions presented during the workshop, LES seems to be a robust and reliable technique for practical ap- plications in numerous high-end technological applications. However, many problems still remain open and were discussed during the workshop, e.g. re- garding SGS closure in special applications, validation of numerical results against experimental, real-life data, and accuracy of the algorithms currently in use for the numerical integration of the governing equations. A general trend in fluid mechanics conferences is that the amount of work presented on very fundamental issues such as subgrid-scale modelling is observed to persist, while complex physical phenomena and applications are teated to an Preface VII increasing extent. In this scenery, the series of DLES workshops sees itself as ahostforfundamentalresearchonDNSandLESandwillcontinuetobethat in the future. The present book summarizes the written contributions to the seventh DLES workshop.As usual for a DLES workshop,the quality of the presenta- tions was very high, and the same applies to the corresponding papers. This was furthermore ensured by an extensive peer-review process. The organizers were delighted about the stimulating atmosphere and the constructivediscussions atthis workshop.This is to a largeextentdue to the participants and the organizers are greatful for that. They find it rewarding that the workoforganizingthis meeting turned into sucha success.Maythis book be of much use for the reader and find widespread distribution. Vincenzo Armenio Jochen Fro¨hlich Bernard J. Geurts Contents Part I Fundamentals Wall-Modeled Large-Eddy Simulations: Present Status and Prospects Ugo Piomelli .................................................... 3 A Study of the Influence of the Reynolds Number on Jet Self-Similarity Using Large-Eddy Simulation Christophe Bogey and Christophe Bailly ............................ 13 Direct Numerical Simulation of Fractal-Generated Turbulence S. Laizet and J. Christos Vassilicos................................. 19 Turbulent Oscillating Channel Flow Subjected to Wind Stress W. Kramer, H.J.H. Clercx, and V. Armenio ........................ 27 DNS of a Periodic Channel Flow with Isothermal Ablative Wall O. Cabrit and F. Nicoud.......................................... 35 Diagnostic Properties of Structure Tensors in Turbulent Flows D.G.E. Grigoriadis, C.A. Langer, and S.C. Kassinos ................. 43 Development of Brown–Roshko Structures in the Mixing Layer Behind a Splitter Plate Neil D. Sandham and Richard D. Sandberg.......................... 51 DNS of Spatially-Developing Three-Dimensional Turbulent Boundary Layers Philipp Schlatter and Luca Brandt ................................. 57 Direct Numerical Simulation and Experimental Results of a Turbulent Channel Flow with Pin Fins Array B. Cruz Perez, J. Toro Medina, N. Sundaram, K. Thole, and S. Leonardi.................................................. 65