Large Eddy Simulation (LES) is a high-fidelity approach to the numerical simulation of turbulent flows. Recent developments have shown LES to be able to predict aerodynamic noise generation and propagation as well as the turbulent flow, by means of either a hybrid or a direct approach. This book is based on the results of two French/German research groups working on LES simulations in complex geometries and noise generation in turbulent flows. The results provide insights into modern prediction approaches for turbulent flows and noise generation mechanisms as well as their use for novel noise reduction concepts.

This book gathers the proceedings of the 11th workshop on Direct and Large Eddy Simulation (DLES), which was held in Pisa, Italy in May 2017. The event focused on modern techniques for simulating turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structures, as Direct Numerical Simulation (DNS), Large-Eddy Simulation (LES) or hybrid models based on a combination of LES and RANS approaches. In light of the growing capacities of modern computers, these approaches have been gaining more and more interest over the years and will undoubtedly be developed and applied further. The workshop offered a unique opportunity to establish a state-of-the-art of DNS, LES and related techniques for the computation and modeling of turbulent and transitional flows and to discuss about recent advances and applications. This volume contains most of the contributed papers, which were submitted and further reviewed for publication. They cover advances in computational techniques, SGS modeling, boundary conditions, post-processing and data analysis, and applications in several fields, namely multiphase and reactive flows, convection and heat transfer, compressible flows, aerodynamics of airfoils and wings, bluff-body and separated flows, internal flows and wall turbulence and other complex flows.

A new finite volume algorithm has been developed to solve a variety of flows by using large eddy simulation and direct numerical simulation. This finite volume algorithm was developed using a dual time stepping approach with a preconditioning technique and a new factorization implementation. The method takes the advantage of pressure based and density-based methods. Thus, it provides an efficient way to numerically solve the Navier-Stokes equations at the low Mach numbers. Meanwhile, to generate the inflow conditions for the simulation of turbulent boundary layers, a dynamic recycling method was proposed. In addition, a characteristic boundary condition method was suggested for the outlet boundary conditions of external wall shear flows. The implementation of the methods was validated by obtaining solutions to a number of flows including turbulent boundary layers with or without heat transfer, turbulent boundary layers subjected to free stream turbulence, and supersonic adiabatic turbulent boundary layers. Good agreement between the present results and benchmark results in the literature was achieved. With the new numerical method and boundary condition technique it is possible to investigate the statistics of turbulence with greater accuracy. Thus, the fluid physics of three different turbulent boundary layers are discussed. These are a turbulent boundary layer without heat transfer, a turbulent boundary layer on a heated wall, and an adiabatic supersonic turbulent boundary layer at Mach number 1.8. The incompressible turbulent boundary layer study focused on the two-point correlation and the anisotropy. The compressible turbulent boundary layers study, that is, the low Mach number turbulent boundary layer with strong heat transfer and the supersonic turbulent boundary layer, is concerned with the strong Reynolds analogy, Van Driest transformation, and the applicability of Morkovin's hypothesis. Large eddy simulation is applied to an example discrete hole film cooling configuration. The computational domain included the coolant supply tube as well as the main mixing region. A tube L/D of 8 and an injection angle of 35 degrees was employed for two different simulations: one was with a blowing ratio of 0.5, and the other was with a blowing ratio of 0.362.

This book gathers the proceedings of the Fifth Symposium on Hybrid RANS-LES Methods, which was held on March 19-21 in College Station, Texas, USA. The different chapters, written by leading experts, reports on the most recent developments in flow physics modelling, and gives a special emphasis to industrially relevant applications of hybrid RANS-LES methods and other turbulence-resolving modelling approaches. The book addresses academic researchers, graduate students, industrial engineers, as well as industrial R&D managers and consultants dealing with turbulence modelling, simulation and measurement, and with multidisciplinary applications of computational fluid dynamics (CFD), such as flow control, aero-acoustics, aero-elasticity and CFD-based multidisciplinary optimization. It discusses in particular advanced hybrid RANS-LES methods. Further topics include wall-modelled Large Eddy Simulation (WMLES) methods, embedded LES, and a comparison of the LES methods with both hybrid RANS-LES and URANS methods. Overall, the book provides readers with a snapshot on the state-of-the-art in CFD and turbulence modelling, with a special focus to hybrid RANS-LES methods and their industrial applications.