Large Eddy Simulation for Compressible Flows Scientific Computation Editorial Board J.-J. Chattot, Davis, CA, USA P. Colella, Berkeley, CA, USA W. Eist, Princeton, NJ, USA R. Glowinski, Houston, TX, USA Y. Hussaini, Tallahassee, FL, USA P. Joly, Le Chesnay, France H.B. Keller, Pasadena, CA, USA J.E. Marsden, Pasadena, CA, USA D.I. Meiron, Pasadena, CA, USA O. Pironneau, Paris, France A. Quarteroni, Lausanne, Switzerland and Politecnico of Milan, Milan, Italy J. Rappaz, Chicago, IL, USA R. Rosner, Paris, France P. Sagaut, Pasadena, CA, USA J.H. Seinfeld, Pasadena, CA, USA A. Szepessy, Stockholm, Sweden M.F. Wheeler, Austin, TX, USA For other titles published in this series, go to www.springer.com/series/718 E. Garnier (cid:2) N. Adams (cid:2) P. Sagaut Large Eddy Simulation for Compressible Flows Dr. E. Garnier Prof. Dr. N. Adams Office National d’E´tudes Institute of Aerodynamics et de Recherches A´erospatiales Technische Universit¨at Mu¨nchen 8 rue des Vertugadins 85747 Garching 92190 Meudon Germany France e-mail: [email protected] e-mail: [email protected] Prof. P. Sagaut Institut Jean Le Rond d’Alembert Universit´e Pierre et Marie Curie Boite 162 4, place Jussieu 75252 Paris Cedex 5 France e-mail: [email protected] ISBN 978-90-481-2818-1 e-ISBN 978-90-481-2819-8 DOI 10.1007/978-90-481-2819-8 LibraryofCongressControlNumber:2009933039 (cid:2)cSpringerScience+BusinessMediaB.V.2009 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any materialsuppliedspecificallyforthepurposeofbeingenteredandexecutedonacomputer system,forexclusiveusebythepurchaserofthework. Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Contents 1 Introduction............................................... 1 2 LES Governing Equations ................................. 5 2.1 Preliminary Discussion ................................... 5 2.2 Governing Equations..................................... 6 2.2.1 Fundamental Assumptions.......................... 6 2.2.2 Conservative Formulation .......................... 7 2.2.3 Alternative Formulations ........................... 9 2.3 Filtering Operator....................................... 9 2.3.1 Definition ........................................ 10 2.3.2 Discrete Representation of Filters ................... 14 2.3.3 Filtering of Discontinuities.......................... 16 2.3.4 Filter Associated to the Numerical Method ........... 18 2.3.5 Commutation Error ............................... 20 2.3.6 Favre Filtering .................................... 20 2.3.7 Summary of the Different Type of Filters............. 22 2.4 Formulation of the Filtered Governing Equations ............ 22 2.4.1 Enthalpy Formulation.............................. 23 2.4.2 Temperature Formulation .......................... 24 2.4.3 Pressure Formulation .............................. 24 2.4.4 Entropy Formulation .............................. 25 2.4.5 Filtered Total Energy Equations .................... 26 2.4.6 Momentum Equations ............................. 29 2.4.7 Simplifying Assumptions ........................... 30 2.5 Additional Relations for LES of Compressible Flows ......... 33 2.5.1 Preservation of Original Symmetries ................. 33 2.5.2 Discontinuity Jump Relations for LES ............... 35 2.5.3 Second Law of Thermodynamics .................... 37 2.6 Model Construction...................................... 38 2.6.1 Basic Hypothesis .................................. 38 2.6.2 Modeling Strategies................................ 39 E. Garnier et al., Large Eddy Simulation for Compressible Flows, Scientific Computation, (cid:2)c Springer Science + Business Media B.V. 2009 vi Contents 3 Compressible Turbulence Dynamics ....................... 41 3.1 Scope and Content of This Chapter........................ 41 3.2 Kovasznay Decomposition of Turbulent Fluctuations ......... 42 3.2.1 Kovasznay’s Linear Decomposition .................. 42 3.2.2 Weakly Nonlinear Kovasznay Decomposition.......... 45 3.3 Statistical Description of Compressible Turbulence........... 46 3.4 Shock-Turbulence Interaction ............................. 48 3.4.1 Introduction to the Linear Interaction Approximation Theory........................................... 48 3.4.2 Vortical Turbulence-Shock Interaction................ 49 3.4.3 Mixed-Mode Turbulence-Shock Interaction ........... 57 3.4.4 Consequences for Subgrid Modeling.................. 62 3.5 Different Regimes of Isotropic Compressible Turbulence ...... 64 3.5.1 Quasi-Isentropic-Turbulence Regime ................. 65 3.5.2 Nonlinear Subsonic Regime ......................... 71 3.5.3 Supersonic Regime ................................ 74 3.5.4 Consequences for Subgrid Modeling.................. 75 4 Functional Modeling....................................... 77 4.1 Basis of Functional Modeling ............................. 77 4.1.1 Phenomenology of Scale Interactions................. 77 4.1.2 Basic Functional Modeling Hypothesis ............... 79 4.2 SGS Viscosity........................................... 79 4.2.1 The Boussinesq Hypothesis ......................... 79 4.2.2 Smagorinsky Model................................ 81 4.2.3 Structure Function Model .......................... 82 4.2.4 Mixed Scale Model ................................ 82 4.3 Isotropic Tensor Modeling ................................ 83 4.4 SGS Heat Flux.......................................... 84 4.5 Modeling of the Subgrid Turbulent Dissipation Rate ......... 85 4.6 Improvement of SGS models .............................. 85 4.6.1 Structural Sensors and Selective Models.............. 85 4.6.2 Accentuation Technique and Filtered Models.......... 87 4.6.3 High-Pass Filtered Eddy Viscosity................... 88 4.6.4 Wall-Adapting Local Eddy-Viscosity Model........... 88 4.6.5 Dynamic Procedure................................ 89 4.6.6 Implicit Diffusion and the Implicit LES Concept ...... 93 5 Explicit Structural Modeling .............................. 95 5.1 Motivation of Structural Modeling......................... 95 5.2 Models Based on Deconvolution ........................... 97 5.2.1 Scale-Similarity Model .............................100 5.2.2 Approximate Deconvolution Model ..................103 5.2.3 Tensor-Diffusivity Model ...........................105 5.3 Regularization Techniques ................................105 Contents vii 5.3.1 Eddy-Viscosity Regularization ......................106 5.3.2 Relaxation Regularization ..........................109 5.3.3 Regularization by Explicit Filtering..................111 5.4 Multi-Scale Modeling of Subgrid-Scales.....................113 5.4.1 Multi-Level Approaches ............................113 5.4.2 Stretched-Vortex Model ............................116 5.4.3 Variational Multi-Scale Model.......................117 6 Relation Between SGS Model and Numerical Discretization..............................................119 6.1 Systematic Procedures for Nonlinear Error Analysis..........119 6.1.1 Error Sources .....................................119 6.1.2 Modified Differential Equation Analysis ..............121 6.1.3 Modified Differential Equation Analysis in Spectral Space ............................................126 6.2 Implicit LES Approaches Based on Linear and Nonlinear Discretization Schemes ...................................129 6.2.1 The Volume Balance Procedure of Schumamm ........129 6.2.2 The Kawamura-Kuwahara Scheme...................130 6.2.3 The Piecewise-Parabolic Method ....................131 6.2.4 The Flux-Corrected-Transport Method...............132 6.2.5 The MPDATA Method.............................136 6.2.6 The Optimum Finite-Volume Scheme ................138 6.3 Implicit LES by Adaptive Local Deconvolution..............140 6.3.1 Fundamental Concept of ALDM.....................140 6.3.2 ALDM for the Incompressible Navier-Stokes Equations.143 6.3.3 ALDM for the Compressible Navier-Stokes Equations ..148 7 Boundary Conditions for Large-Eddy Simulation of Compressible Flows........................................155 7.1 Introduction ............................................155 7.2 Wall Modeling for Compressible LES.......................156 7.2.1 Statement of the Problem ..........................156 7.2.2 Wall Boundary Conditions in the Kovasznay Decomposition Framework: an Insight................156 7.2.3 TurbulentBoundaryLayer:VorticityandTemperature Fields............................................159 7.2.4 Turbulent Boundary Layer: Acoustic Field............163 7.2.5 Consequences for the Development of Compressible Wall Models ......................................169 7.2.6 Extension of Existing Wall Models for Incompressible Flows............................................170 7.3 Unsteady Turbulent Inflow Conditions for Compressible LES..172 7.3.1 Fundamentals.....................................172 7.3.2 Precursor Simulation: Advantages and Drawbacks .....174 viii Contents 7.3.3 Extraction-Rescaling Techniques ....................175 7.3.4 Synthetic-Turbulence-Based Models..................179 8 Subsonic Applications with Compressibility Effects ........185 8.1 Homogeneous Turbulence.................................185 8.1.1 Context ..........................................185 8.1.2 A Few Realizations ................................186 8.1.3 Influence of the Numerical Method ..................187 8.1.4 SGS Modeling ....................................190 8.2 Channel Flow...........................................191 8.2.1 Context ..........................................191 8.2.2 A Few Realizations ................................191 8.2.3 Influence of the Numerical Method ..................192 8.2.4 Influence of the SGS Model.........................194 8.3 Mixing Layer ...........................................195 8.3.1 Context ..........................................195 8.3.2 A Few Realizations ................................195 8.3.3 Influence of the Numerical Method ..................196 8.3.4 Influence of the SGS Model.........................197 8.4 Boundary-Layer Flow ....................................198 8.4.1 Context ..........................................198 8.4.2 A Few Realizations ................................198 8.5 Jets....................................................200 8.5.1 Context ..........................................200 8.5.2 A Few Realizations ................................201 8.5.3 Influence of the Numerical Method ..................202 8.5.4 Influence of the SGS Model.........................204 8.5.5 Physical Analysis..................................205 8.6 Flows over Cavities ......................................206 8.6.1 Context ..........................................206 8.6.2 A Few Realizations ................................206 8.6.3 Influence of the Numerical Method ..................207 8.6.4 Influence of the SGS Model.........................208 8.6.5 Physical Analysis..................................208 9 Supersonic Applications ...................................211 9.1 Homogeneous Turbulence.................................211 9.2 Channel Flow...........................................212 9.2.1 Context ..........................................212 9.2.2 A Few Realizations ................................212 9.2.3 Influence of the Numerical Method ..................213 9.2.4 Influence of the Grid Resolution.....................214 9.2.5 Influence of the SGS Model.........................215 9.3 Boundary Layers ........................................215 9.3.1 Context ..........................................215 Contents ix 9.3.2 A Few Realizations ................................216 9.3.3 Influence of the Numerical Method ..................216 9.3.4 Influence of the Grid Resolution.....................217 9.3.5 SGS Modeling ....................................219 9.4 Jets....................................................220 9.4.1 Context ..........................................220 9.4.2 A Few Realizations ................................220 9.4.3 Influence of the Numerical Method ..................221 9.4.4 Influence of the SGS Model.........................221 9.4.5 Physical Analysis..................................221 10 Supersonic Applications with Shock-Turbulence Interaction ................................................223 10.1 Shock-Interaction with Homogeneous Turbulence ............224 10.1.1 Phenomenology of Shock-Interaction with Homogeneous Turbulence...........................224 10.1.2 LES of Shock-Interaction with Homogeneous Turbulence .......................................228 10.2 Shock-Turbulence Interaction in Jets.......................230 10.2.1 Phenomenology of Shock-Turbulence Interaction in Jets .............................................230 10.2.2 LES of Shock-Turbulence Interaction in Jets ..........231 10.3 Shock-Turbulent-Boundary-Layer Interaction ...............233 10.3.1 Phenomenology of Shock-Turbulent-Boundary-Layer Interaction .......................................233 10.3.2 LES of Compression-Ramp Configurations............237 References.....................................................255 Index..........................................................273 1 Introduction Turbulent flows are ubiquitous in most application fields, ranging from en- gineering to earth sciences and even life sciences. Therefore, simulation of turbulent flows has become a key tool in both fundamental and applied re- search. The complexity of Navier–Stokes turbulence, which is illustrated by the fact that the number of degrees of freedom of turbulence grows faster than O(Re11/4), where Re denotes the Reynolds number, renders the Direct Numerical Simulation (DNS) of turbulence inapplicable to most flows of in- terest. To alleviate this problem, truncated solutions in both frequency and wavenumbermaybesought,whosecomputationalcostismuchlowerandmay ideally be arbitrarily adjusted. The most suitable approach to obtain such a low-cost three-dimensional unsteady simulation of a turbulent flow is Large- EddySimulation(LES),whichwaspioneeredtocomputemeteorologicalflows in the late 1950s and the early 1960s. One of the main issues raised by LES is a closure problem: because of the non-linearity of the Navier–Stokes equations, the effect of unresolved scales must be taken into account to recover a reliable description of resolved scales of motion (Chap. 2). This need to close the governing equations of LES has certainly been the main area of investigation since the 1960s, and numerous closures,alsoreferredtoassubgridmodels,havebeenproposed.Mostexisting subgridmodelshavebeenbuiltusingsimplifiedviewsofturbulencedynamics, themainphysicalphenomenontakenintoaccountbeingthedirectkineticen- ergycascadefromlargetosmallscalesthatisobservedinisotropicturbulence and high-Reynolds fully developed turbulent flows. The most popular para- digm for interscale energy transfer modeling is subgrid viscosity (Chap. 4), whichisaneasywaytoaccountforthenetpumpingofresolvedkineticenergy by unresolved scales. Other models have been based on mathematical manip- ulations of governing equations, such as approximate deconvolution, and are, at least theoretically, more general since they are not based on a priori as- sumptions on turbulence dynamics (Chap. 5). An important observation is that the vast majority of existing works dealing with subgrid modeling is de- voted to incompressible flows, the main extension being for variable-density E. Garnier et al., Large Eddy Simulation for Compressible Flows, Scientific Computation, (cid:2)c Springer Science + Business Media B.V. 2009