Werner Haase - Böcker

This book offers detailed insights into new methods for high-fidelity CFD, and their industrially relevant applications in aeronautics.

This book offers detailed insights into new methods for high-fidelity CFD, and their industrially relevant applications in aeronautics.

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.

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.

This book reports on the EU-funded 7th Framework project, Go4Hybrid (Grey Area Mitigation for Hybrid RANS-LES Methods). It presents new findings concerning the accuracy and reliability of current hybrid RANS-LES methods. It describes improved formulations of both non-zonal and embedded hybrid strategies, together with their validation in a broad range of flow cases, and highlighting some key industrial applications. The book provides students, researchers and professionals in the field of applied computational fluid dynamics with a timely, practice-oriented reference guide.

This book reports on the EU-funded 7th Framework project, Go4Hybrid (Grey Area Mitigation for Hybrid RANS-LES Methods). The book provides students, researchers and professionals in the field of applied computational fluid dynamics with a timely, practice-oriented reference guide.

This volume contains contributions to the BRI-TE/EURAM, Area 5, Pilot phase programme on the validation of computational fluid dynamics (CFD) codes, EUROVAL. Two- and three-dimensional flows are investigated with particular emphasis on precise comparison against measurements, with special attention paid to the validation of turbulence models investigated by the 16 project partners. The main part of this volume is designated to the validation of turbulence models on a boundary layer and Navier-Stokes basis, presented in an application-oriented structure for single- and two-element aerofoils, internal flow over bumps, wind-tunnel-interference problems and a vortex breakdown study.

This volume contains results gained from the EU-funded 5th Framework project, FLOMANIA (Flow Physics Modelling – An Integrated Approach). 17 European organisations, industry, research, and universities, have collaborated on topics of improvement of existing methods, investigation and integration of differential Reynolds Stress models for aeronautical applications and modelling of detached-eddy simulations (DES). The book presents an introduction to the project, exhibits partners’ methods and approaches, and provides comprehensive reports (i.e. definition as well as results) of all applications treated in the project. Moreover, a complete chapter is devoted to a description of turbulence models used by the partners together with a section on lessons learnt - accompanied by a comprehensive list of references.

This volume contains results gained from the EU-funded 4th Framework project, UNSI (Unsteady Viscous Flows in the Context of Fluid-Structure Interaction). Fifteen European organizations (industrial firms, research labs, and universities) have collaborated on the topic of non-linear, static and dynamic aeroelasticity applications with some special emphasis on the improvement of CFD methods applied to unsteady flow. Hence, the book is split into five main parts: project descriptions (with points of contact for the interested reader), summaries of work performed by each partner, summaries of work carried out in the work tasks, application-oriented syntheses, and, last but not least, conclusions and lessons learned.

Turbulence modelling has long been, and will remain, one of the most important t- ics in turbulence research, challenging scientists and engineers in the academic world and in the industrial society. Over the past decade, Detached Eddy Simulation (DES) and other hybrid RANS-LES methods have received increasing attention from the turbulence-research community, as well as from industrial CFD engineers. Indeed, as an engineering modelling approach, hybrid RANS-LES methods have acquired a remarkable profile in modelling turbulent flows of industrial interest in relation to, for example, transportation, energy production and the environment. The advantage exploited with hybrid RANS-LES modelling approaches, being - tentially more computationally efficient than LES and more accurate than (unsteady) RANS, has motivated numerous research and development activities. These activities, together with industrial applications, have been further facilitated over the recent years by the rapid development of modern computing resources. As a European initiative, the EU project DESider (Detached Eddy Simulation for Industrial Aerodynamics, 2004-2007), has been one of the earliest and most systematic international R&D effort with its focus on development, improvement and applications of a variety of existing and new hybrid RANS-LES modelling approaches, as well as on related numerical issues. In association with the DESider project, two subsequent international symposia on hybrid RANS-LES methods have been arranged in Stockholm (Sweden, 2005) and in Corfu (Greece, 2007), respectively. The present book is a result of the Second Symposium on Hybrid RANS-LES Methods, held in Corfu, Greece, 17-18 June 2007.

Preface “In aircraft design, efficiency is determined by the ability to accurately and rel- bly predict the occurrence of, and to model the development of, turbulent flows. Hence, the main objective in industrial computational fluid dynamics (CFD) is to increase the capabilities for an improved predictive accuracy for both complex flows and complex geometries”. This text part taken from Haase et al (2006), - scribing the results of the DESider predecessor project “FLOMANIA” is still - and will be in future valid. With an ever-increasing demand for faster, more reliable and cleaner aircraft, flight envelopes are necessarily shifted into areas of the flow regimes exhibiting highly unsteady and, for military aircraft, unstable flow behaviour. This undou- edly poses major new challenges in CFD; generally stated as an increased pred- tive accuracy whist retaining “affordable” computation times. Together with highly resolved meshes employing millions of nodes, numerical methods must have the inherent capability to predict unsteady flows. Although at present, (U)RANS methods are likely to remain as the workhorses in industry, the DESider project focussed on the development and combination of these approaches with LES methods in order to “bridge” the gap between the much more expensive (due to high Reynolds numbers in flight), but more accurate (full) LES.

This volume offers of the EU-funded 5th Framework project, FLOMANIA (Flow Physics Modelling -- An Integrated Approach). The book presents an introduction to the project, exhibits partners' methods and approaches, and provides comprehensive reports of all applications treated in the project. A complete chapter is devoted to a description of turbulence models used by the partners together with a section on lessons learned, accompanied by a comprehensive list of references.

This volume contains results gained from the EU-funded 4th Framework project, UNSI (Unsteady Viscous Flows in the Context of Fluid-Structure Interaction). Fifteen European organizations (industrial firms, research labs, and universities) have collaborated on the topic of non-linear, static and dynamic aeroelasticity applications with some special emphasis on the improvement of CFD methods applied to unsteady flow. Hence, the book is split into five main parts: project descriptions (with points of contact for the interested reader), summaries of work performed by each partner, summaries of work carried out in the work tasks, application-oriented syntheses, and, last but not least, conclusions and lessons learned.

This volume contains papers contributed to the Second Symposium on Hybrid RANS-LES Methods, held in Corfu, Greece, 17-18 June 2007. All the papers have undergone further review and revision after the symposium, which has covered a number of relevant topics in the field. These include Unsteady RANS and LES, Improved DES Methods, Hybrid RANS-LES Methods, Embedded LES, DES-related Numerical Issues, Performance of the New SAS Model, as well as Industrial Applications of DES. Papers represent a leading part of current studies and achievements on the fundamentals of hybrid RANS-LES methods in general, as well as on their applications to industrial flow problems. Among the contributed papers, three invited keynote papers by B. Geurts, U. Piomelli and P. Sagaut, are presented together with an overview paper by P. Spalart.

Preface “In aircraft design, efficiency is determined by the ability to accurately and rel- bly predict the occurrence of, and to model the development of, turbulent flows. Hence, the main objective in industrial computational fluid dynamics (CFD) is to increase the capabilities for an improved predictive accuracy for both complex flows and complex geometries”. This text part taken from Haase et al (2006), - scribing the results of the DESider predecessor project “FLOMANIA” is still - and will be in future valid. With an ever-increasing demand for faster, more reliable and cleaner aircraft, flight envelopes are necessarily shifted into areas of the flow regimes exhibiting highly unsteady and, for military aircraft, unstable flow behaviour. This undou- edly poses major new challenges in CFD; generally stated as an increased pred- tive accuracy whist retaining “affordable” computation times. Together with highly resolved meshes employing millions of nodes, numerical methods must have the inherent capability to predict unsteady flows. Although at present, (U)RANS methods are likely to remain as the workhorses in industry, the DESider project focussed on the development and combination of these approaches with LES methods in order to “bridge” the gap between the much more expensive (due to high Reynolds numbers in flight), but more accurate (full) LES.

Hybrid modelling of turbulent flows, combining RANS and LES techniques, has received increasing attention over the past decade to fill the gap between (U)RANS and LES computations in aerodynamic applications at industrially relevant Reynolds numbers. With the advantage of hybrid RANS-LES modelling approaches, being considerably more computationally efficient than full LES and more accurate than (U)RANS, particularly for unsteady aerodynamic flows, has motivated numerous research and development activities. These activities have been increasingly stimulated by the provision of modern computing facilities. The present book contains the contributions presented at the Third Symposium on Hybrid RANS-LES Methods, held in Gdansk, Poland, 10-12 June 2009. To a certain extent, this conference was a continuation of the first symposium taking place in Stockholm (Sweden, 2005) and the second in Corfu (Greece, 2007). Motivated by the extensive interest in the research community, the papers presented at the Corfu symposium were published by Springer in the book entitled “Advances in Hybrid RANS-LES Modelling” (in Notes on Numerical Fluid Mechanics and Multidisciplinary Design, Vol. 97). At the Gdansk symposium, along with four invited keynotes, given respectively by S. Fu, U. Michel, M. Sillen and P. Spalart, another 28 papers were presented on the following topics: Unsteady RANS, LES, Improved DES Methods, Hybrid RANS-LES Methods, DES versus URANS and other Hybrid Methods, Modelli- related Numerical Issues and Industrial Applications. After the symposium all full papers have been further reviewed and revised for publication in the present book.

The present book contains contributions presented at the Fourth Symposium on Hybrid RANS-LES Methods, held in Beijing, China, 28-30 September 2011, being a continuation of symposia taking place in Stockholm (Sweden, 2005), in Corfu (Greece, 2007), and Gdansk (Poland, 2009). The contributions to the last two symposia were published as NNFM, Vol. 97 and Vol. 111. At the Beijing symposium, along with seven invited keynotes, another 46 papers (plus 5 posters) were presented addressing topics on Novel turbulence-resolving simulation and modelling, Improved hybrid RANS-LES methods, Comparative studies of difference modelling methods, Modelling-related numerical issues and Industrial applications.. The present book reflects recent activities and new progress made in the development and applications of hybrid RANS-LES methods in general.

The present book contains contributions presented at the Fourth Symposium on Hybrid RANS-LES Methods, held in Beijing, China, 28-30 September 2011, being a continuation of symposia taking place in Stockholm (Sweden, 2005), in Corfu (Greece, 2007), and Gdansk (Poland, 2009). The contributions to the last two symposia were published as NNFM, Vol. 97 and Vol. 111. At the Beijing symposium, along with seven invited keynotes, another 46 papers (plus 5 posters) were presented addressing topics on Novel turbulence-resolving simulation and modelling, Improved hybrid RANS-LES methods, Comparative studies of difference modelling methods, Modelling-related numerical issues and Industrial applications.. The present book reflects recent activities and new progress made in the development and applications of hybrid RANS-LES methods in general.