Download or read book Mod lisation 0D 1D de la Combustion Pour L optimisation Des Syst mes de Combustion Des Moteurs Allumage Command written by Sokratis Demesoukas and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, the design of Spark Ignition internal combustion engines is focused on the reduction of fuel consumption and low pollutant emissions, while conserving an adequate output power. The high cost of experimental testing comes in favor of the use of numerical simulations for the assessment of engine technologies. Phenomenological Zero-Dimensional combustion models allow evaluating various technical concepts since they take into account various aspects of spark ignition combustion such as chamber geometry, laminar flame characteristics (thickness and speed) and the impact of turbulence. Such models also calculate species concentration of the exhaust gases. In order to create a zero-dimensional combustion model, which can be able to describe correctly the physics of combustion, the key aspects of laminar and turbulent premixed combustion are identified. Three versions of typical combustion models are compared in terms of physical description of the combustion process. The result of this comparison indicated the most physically pertinent mod-el (the Flame Surface Density model). This model is retained and is enhanced with physical modeling of the several phenomena, which affect the heat release rate. Those phenomena are the wall-flame interaction, post-flame reactions and flame stretch. Finally, the proposed model is validated for several engine configurations. Each configuration has an impact on a specific engine parameter. This analysis shows which are the confidence intervals and the limitations of the proposed model.
Download or read book Mod lisation 0 1D des moteurs allumage command written by Vincent Talon and published by . This book was released on 2004 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les normes de pollution de plus en plus drastiques et les temps de développement des moteurs à combustion interne de plus en plus courts imposent d'utiliser des modèles embarqués pour le contrôle ainsi que pour l'étude paramétrique lors les phases de dimensionnement et d'optimisation. La modélisation physique 0-1D des moteurs à allumage commandé permet de prédire le remplissage et le déroulement de la combustion aussi bien en phase stationnaire que transitoire avec un excellent niveau de fiabilité et de corrélation par rapport aux essais tout en respectant les contraintes de pas de calcul permettant de réaliser des simulations en temps réel. Deux grands thèmes ont été abordés : La modélisation de l'acoustique des tubulures : - Nouveau modèle bondgraph d'acoustique basé sur l'approche de Godunov et de Roe - Méthode pour prendre en compte les conditions aux limites - Modèle 0D de turbocompresseur (avec approximation des champs compresseur et turbine) La modélisation de la combustion : - Modèle de Wiebe en formulation bondgraph (avec une méthode d'identification) - Modèle Eddy Burn Up en formulation bondgraph (avec une méthode d'identification) - Deux nouvelles méthodes de prise en compte de la variation cyclique
Download or read book Development of Meshless Methods and Application to Numerical Simulation of Internal Aerodynamic Combustion Engine written by Yohan Blacodon and published by . This book was released on 2011 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: La simulation numérique de l'aérodynamique interne des chambres de combustion de moteurs automobiles est caractérisée par des déplacements complexes d'éléments mobiles (piston, soupapes d'admission et d'échappement,...) et par de fortes variations volumétriques, qui causent régulièrement des problèmes numériques avec les méthodes classiques utilisant des maillages du domaine de calcul. Avec ces méthodes (EF, VF), qui utilisent des éléments polyhèdriques (hexahèdres, tétrahèdres, prismes,...), il est nécessaire de changer périodiquement le maillage, afin de s'adapter à la nouvelle géométrie. Cette étape de remaillage est très fastidieuse et coûteuse en terme de temps ingénieur et peut réduire la précision des calculs numériques par un excès de viscosité numérique produite durant le processus d'interpolation des variables, d'un maillage à un autre. Récemment, la communauté des chercheurs a renouvelé son intérêt pour le développement d'une génération de méthodes numériques permettant de s'abroger des problèmes rencontrés avec les méthodes classiques. A travers la large variété de méthodes innovantes sans maillage, la méthode Smoothed Particle Hydrodynamics (SPH), semble être la plus adaptée à la modélisation de la dynamique des fluides, qui est généralement la plus étudiée. La méthode SPH est utilisée dans divers domaines, tels que l'astrophysique, l'hydrodynamique, la mécanique des solides,... mais à nôtre connaissance il n'existe pas à ce jour de code SPH dédié à l'aérodynamique interne des moteurs à combustion, ou à des écoulements fortement compressible en milieu confiné. Ainsi une évaluation, plusieurs développements et divers tests numériques sont nécessaires afin de pouvoir juger de l'efficacité de la méthode SPH lorsqu'elle est confrontée à ce genre de problématiques. Le but de ce travail de thèse est de valider, à travers divers développement et applications, la méthode SPH pour des problèmes traitant des écoulements compressibles et turbulents. Ainsi, partant du code SPH tridimensionnel quasi-incompressible, nommé SPARTACUS-3D, et initialement développé à EDF (France), l'objectif de la présente thèse est de modifier ce code afin d'être capable de réaliser des simulations d'écoulements compressibles et turbulents caractéristiques des écoulements présents en chambres de combustion de moteurs automobiles.
Download or read book Steady and Transient Performance Prediction of Gas Turbine Engines written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Secondary Flows in Turbomachines written by Von Karman Institute for Fluid Dynamics and published by . This book was released on 1975 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NSWC TR written by Naval Surface Weapons Center and published by . This book was released on 1979 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aircraft Fire Safety written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Symposium and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Conference Proceedings contains 38 papers presented at the Propulsion and Energetics Panel 73rd Symposium on 'Aircraft Fire Safety' which was held 22 - 26 May 1989 in Sintra, Portugal. The Symposium was arranged in the following sessions: Review of Fire-Related Aircraft Accidents (3); Fire Safety Standards and Research Programmes (6); Aircraft Internal Fires (9); Aircraft External Fires (2); Fire Safety of Military Weapon Systems (3); Fire Hardening by Advanced Materials and Structural Design (8); Passenger Behaviour in Emergency Situations (3); and Passenger Protective Equipment (4). The Technical Evaluation Report and and Addendum are included at the beginning of the Proceedings. Questions and answers of the discussions follow each paper. The last AGARD review on the subject took place in a Specialists' Meeting in 1975, followed by a Working Group Report in 1979 and Lecture Series in 1982. The purpose of the Symposium was a review of the present state-of-the-art and of the last improvements. Although the safety standards in aviation are already very high, there is still room for improvements. They are listed in the Conclusions and Recommendations of the Technical Evaluation Report and in the Addendum.
Download or read book AGARD Conference Proceedings written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hypersonic Combined Cycle Propulsion written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Symposium and published by . This book was released on 1990 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transonic and Supersonic Phenomena in Turbomachines written by and published by . This book was released on 1987 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer and Cooling in Gas Turbines written by and published by . This book was released on 1985 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Advanced Material for Turbomachinery and Rocket Propulsion written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Specialists' Meeting and published by . This book was released on 1989 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Instabilities in Liquid fuelled Propulsion Systems written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Specialists ́Meeting and published by . This book was released on 1989 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
