Computational resources have developed to the level that, for the first time, it is becoming possible to apply large-eddy simulation (LES) to turbulent flow problems of realistic complexity. Many examples can be found in technology and in a variety of natural flows. This puts issues related to assessing, assuring, and predicting the quality of LES into the spotlight. Several LES studies have been published in the past, demonstrating a high level of accuracy with which turbulent flow predictions can be attained, without having to resort to the excessive requirements on computational resources imposed by direct numerical simulations. However, the setup and use of turbulent flow simulations requires a profound knowledge of fluid mechanics, numerical techniques, and the application under consideration. The susceptibility of large-eddy simulations to errors in modelling, in numerics, and in the treatment of boundary conditions, can be quite large due to nonlinear accumulation of different contributions over time, leading to an intricate and unpredictable situation. A full understanding of the interacting error dynamics in large-eddy simulations is still lacking. To ensure the reliability of large-eddy simulations for a wide range of industrial users, the development of clear standards for the evaluation, prediction, and control of simulation errors in LES is summoned. The workshop on Quality and Reliability of Large-Eddy Simulations, held October 22-24, 2007 in Leuven, Belgium (QLES2007), provided one of the first platforms specifically addressing these aspects of LES.

Contenu

Numerical and Mathematical Analysis of Subgrid-Scale-Model and Discretization Errors.- Architecture of Approximate Deconvolution Models of Turbulence*.- Adaptive Turbulence Computation Based on Weak Solutions and Weak Uniqueness.- On the Application of Wavelets to LES Sub-grid Modelling.- Analysis of Truncation Errors and Design of Physically Optimized Discretizations.- Spectral Behavior of Various Subgrid-Scale Models in LES at Very High Reynolds Number.- Performance Assessment of a New Advective Subgrid Model Through Two Classic Benchmark Test Cases.- Assessment of Dissipation in LES Based on Explicit Filtering from the Computation of Kinetic Energy Budget.- Optimal Unstructured Meshing for Large Eddy Simulations.- Analysis of Uniform and Adaptive LES in Natural Convection Flow.- Computational Error-Assessment.- Influence of Time Step Size and Convergence Criteria on Large Eddy Simulations with Implicit Time Discretization.- Assessment of LES Quality Measures Using the Error Landscape Approach.- Analysis of Numerical Error Reduction in Explicitly Filtered LES Using Two-Point Turbulence Closure.- Sensitivity of SGS Models and of Quality of LES to Grid Irregularity.- Anisotropic Grid Refinement Study for LES.- Modelling and Error-Assessment of Near-Wall Flows.- Expectations in the Wall Region of a Large-Eddy Simulation.- Large Eddy Simulation of Atmospheric Convective Boundary Layer with Realistic Environmental Forcings.- Accuracy Close to the Wall for Large-Eddy Simulations of Flow Around Obstacles Using Immersed Boundary Methods.- On the Control of the Mass Errors in Finite Volume-Based Approximate Projection Methods for Large Eddy Simulations.- Error Assessment in Complex Applications.- Reliability of Large-Eddy Simulation of Nonpremixed Turbulent Flames: Scalar Dissipation Rate Modeling and 3D-Boundary Conditions.- LES at Work: Quality Management in Practical Large-Eddy Simulations.- Quality of LES Predictions of Isothermal and Hot Round Jet.- LES for Street-Scale Environments and Its Prospects.- Large Eddy Simulations of the Richtmyer-Meshkov Instability in a Converging Geometry.- Quality Assessment in LES of a Compressible Swirling Mixing Layer.- Accuracy of Large-Eddy Simulation of Premixed Turbulent Combustion.- Mesh Dependency of Turbulent Reacting Large-Eddy Simulations of a Gas Turbine Combustion Chamber.- Analysis of SGS Particle Dispersion Model in LES of Channel Flow.- Numerical Data for Reliability of LES for Non-isothermal Multiphase Turbulent Channel Flow.- Lagrangian Tracking of Heavy Particles in Large-Eddy Simulation of Turbulent Channel Flow.- Large-Eddy Simulation of Particle-Laden Channel Flow.