IUTAM Symposium on Turbulent Mixing and Combustion

Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 2010

This volume contains the papers presented at the 19th DGLR/STAB-Symposium held in Munich, Germany, 4-5 November 2014 and organized by the Institute of Aerodynamics and Fluid Mechanics of the Technische Universität München. STAB is the German Aerospace Aerodynamics Association, founded towards the end of the 1970s and DGLR is the German Society for Aeronautics and Astronautics (Deutsche Gesellschaft für Luft-und Raumfahrt-Lilienthal Oberth e.V.). The mission of STAB is to foster development and acceptance of the disciplines "Aerodynamics and Fluid Mechnics" in Germany. One of its general guidelines is to concentrate resources and know-how in the involved institutions and to avoid duplication in research work as much as possible. Nowadays, this is more necessary than ever. The experience made in the past makes it easier now to obtain new knowledge for solving today's and tomorrow's problems. STAB unites German scientists and engineers from universities, research establishments and industry doing research and project work in numerical and experimental fluid mechanics and aerodynamics for aerospace, ground transportation and other applications. This has always been the basis of numerous common research activities sponsored by different funding agencies. Since 1986 the symposium has taken place at different locations in Germany every 2 years. In between, STAB workshops regularly take place at the DLR in Göttingen. The changing meeting places were established as focal points in Germany's Aerospace Fluid Mechanics Community for a continuous exchange of scientific results and their discussion. Moreover, they are a forum where new research activities can be presented, often resulting in new, commonly organized research and technology projects. It is the tenth time that the contributions to the symposium are published after being subjected to a peer review. The material highlights the key items of integrated research and development based on fruitful collaboration of industry, research establishments and universities. The research areas include airplane and ground vehicle aerodynamics, multidisciplinary optimization and new configurations, turbulence research and modelling, laminar flow control and transition, rotorcraft v

Fluid Mechanics and Its Applications, 1991

The purpose of this series is to focus on subjects in which fluid mechanics plays a fundamental role. As well as the more traditional applications of aeronautics, hydraulics, heat and mass transfer etc., books will be published dealing with topics which are currently in a state of rapid development, such as turbulence, suspensions and multiphase fluids, super and hypersonic flows and numerical modelling techniques.

Progress in Propulsion Physics, 2009

Mixing and combustion in supersonic reacting §ows are currently under investigation for new generation launchers and trans-atmospheric vehicles. Experimental results with hydrogen injected at Mach 2.5 in a Mach 2 airstreams showed combustion taking place just in ∼ 0.6 m: this indicates that supersonic combustion is feasible within short combustors. Large eddy numerical simulations including the subgrid scale (SGS) model, ISCM, developed speci¦cally for supersonic combustion have been done. This model takes into account the e¨ect of compressibility on reaction rates and on mixing. Numerical simulations have revealed that the §ame is unsteady: it anchors at about 15 cm from the injector, develops downstream, and lifts o¨. Periodical ignition and quenching have been investigated. Also, the combustion regime in supersonic §ows has been investigated and is reported.

Flow, Turbulence and Combustion, 2008

The year 2008 marks the 60th anniversary of the continuous publication of our journal, Flow, Turbulence and Combustion. Its title, character, scope and focus, evolved over time to reflect trends and demands and to meet ever changing challenges, but the original aim and mission remained the same, namely to serve the scientific community as a forum for publishing novel ideas and research results in the field of applied physics.

41 st AIAA/ASME/SAE/ …, 2005

Experimental and Numerical Unsteady Characterization of Turbulent Combustion. E Giacomazzi, R Bruschi, S Giammartini, E Giulietti, F Manfredi, C Stringola, S Daniele, G Troiani 41 st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 1-12, 2005. ...

Simulations Numériques Instationnaires de la combustion turbulente et transcritique dans les moteurs cryotechniques Ces 50 dernières années, la majorité des paramètres de conception des moteurs cryotechniques ont été ajustés en l'absence d'une compréhension détaillée de la dynamique de flamme, en raison des limites des diagnostiques expérimentaux et des capacités de calcul. L'objectif de cette thèse est de réaliser des simulations numériques instationnaires d'écoulements réactifs transcritiques de haute fidélité, pour permettre une meilleure compréhension de la dynamique de flamme dans les moteurs cryotechniques et finalement guider leur amélioration. Dans un premier temps, la thermodynamique gaz-réel et son impact sur les schémas numériques sont présentés. Comme la Simulation aux Grandes Echelles (SGE) comporte des équations filtrées, les effets de filtrages induits par la thermodynamique gaz-réel sont ensuite mis en évidence dans une configuration transcritique type et un opérateur de diffusion artificiel, spécifique au gaz réel, est proposé pour lisser les gradients transcritiques en SGE. Dans un deuxième temps, une étude fondamentale du mélange turbulent et de la combustion dans la zone proche-injecteur des moteurs cryotechniques est menée grâce à la Simulation Numérique Directe (SND). Dans le cas non-réactif, les lâchers tourbillonnaires dans le sillage de la lèvre de l'injecteur jouent un rôle majeur dans le mélange turbulent et provoquent la formation de structures en peigne déjà observées expérimentalement dans des conditions similaires. Dans le cas réactif, la flamme reste attachée à la lèvre de l'injecteur, sans extinction locale, et les structures en peigne disparaissent. La structure de flamme est analysée et différents modes de combustion sont identifiés. Enfin, une étude de flamme-jet transcritique H 2 /O 2 , accrochée à un injecteur coaxial avec et sans retrait interne, est menée. Les résultats numériques sont d'abord validés par des données expérimentales pour l'injecteur sans retrait. Ensuite, la configuration avec retrait est comparée à la solution de référence sans retrait et à des données experimentales pour observer les effets de ce paramètre de conception sur l'efficacité de combustion.

2012

A posteriori large-eddy simulations of a turbulent premixed flame in the thin reaction zones regime

Shock Waves, 1999

Laser and Particle Beams, 2003

The conference format consisted of several one hour review talks at the beginning of experimental, computational, and theoretical sessions. These talks were followed by shorter 20-min talks. Two staggered poster sessions were also held at the end of two of the days. There were a total of 126 presentations: 67 oral presentations and 59 poster presentations. Discussion sessions were also held during the poster sessions. The "workshop" provides a common international forum for the exchange of ideas and results and for establishing scientific collaborations. An objective of the conference is to cross-fertilize several disciplines by bringing together experimentalists, numericists, and theorists working in highly diverse areas: high-energy density physics, inertial confinement fusion, astrophysics, and fluid dynamics. Although the sessions were organized according to experimental, computational, and theoretical categories, most of the presentations combined at least two of these. There were 123 participants representing Canada~2!, France~8!, Israel~8!, Japan~4!, Russia~20!, Spain~1!, the United Kingdom~6!, and the United States~74!. Of these, one-third were from universities and the remainder were from national laboratories. The conference was also established as a forum for younger scientists~graduate students

2001

The asymptotic self-similar evolution of the bubble front of the RT and RM instabilities for immiscible fluids is evaluated in 2D and 3D, using solutions to a new formulation of Haan's [1] and Ofer-Shvarts [2] modecoupling models. In the RT case the model result, using the nominal values for Haan's saturation level, is α RT ∼0.04 in 2D, consistent with 2D numerical simulations, and ∼0.05 in 3D, consistent with the LEM experiments [3] but a factor of ∼2 higher than the results of 3D numerical simulations [4]. In the RM case it is shown that the power law exponent is 2/5 in 2D, consistent with the Alon-Shvarts prediction and 2D numerical simulations [5], and 1/3 in 3D, higher than the value of ∼0.25±0.05, obtained in the LEM experiments [3], in 3D numerical simulations [6] and proposed 3D models [7]. The reasons for that large spread in the self-similar parameters and an attempt to put them together in a unified framework will be presented. Newly proposed experiments on NIF, using very long laser pulses, in order to confirm the proposed new framework will be described.