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 Numerical Simulation of Non reactive Aerodynamics in Internal Combustion Engines Using a Hybrid RANS LES Approach written by Al Hassan Afailal and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal aerodynamics is a key element for improving the combustion efficiency in Spark-Ignition (SI) engines. Within this context, CFD tools are increasingly used to investigate in-cylinder flows and to support the design of fuel-efficient engines. The present research aimed at extending and validating a non-zonal hybrid Reynolds-Averaged Navier-Stokes / Temporal Large-Eddy Simulation (HTLES) approach, initially formulated for stationary flows, to cyclic SI engine flows with moving walls. The aim was to model the near-wall regions and coarse mesh regions in RANS, while solving the turbulent scales in core regions with sufficient mesh resolution using temporal LES, in a seamless approach with no a priori user input. HTLES was retained as it proposed a consistent hybridization combining time-averaging in RANS regions with temporal filtering in TLES.A first development consisted in implementing a smooth shielding function that enforces the RANS mode in near-wall regions, regardless of the local temporal and spatial resolution. The extension of HTLES to cyclic flows was then achieved via the formulation of a method allowing approximating the phase averages of resolved flow quantities based on an Exponentially Weighted Average (EWA). A dynamic expression for the width of the weighted average was proposed, in order to ensure that the high frequency turbulent fluctuations be filtered out from the resolved quantities, while keeping the low frequency cyclic components of the flow variables. The resulting EWA-HTLES model was implemented in the commercial CONVERGE CFD code. The developed EWA-HTLES model was first applied to the simulation of two steady flow configurations: a minimal turbulent channel and a steady flow rig. Predictions were confronted with reference data, as well as with those from RANS and LES. All simulations relied on the use of standard wall laws and coarse grids at walls. Imposing the RANS mode at walls yielded EWA-HTLES predictions of pressure losses much closer to DNS and experimental findings than with LES. At the same time, it allowed yielding results in terms of mean and RMS velocities s in the core regions of the same quality than LES, and superior to RANS.Finally, EWA-HTLES was applied to the simulation of two cyclic flows representative of SI engines: the compressed tumble and the Darmstadt single-cylinder pentroof 4valve engine. For each configuration, a total number of 40 consecutive cycles were simulated. The results were confronted to PIV data, and to RANS and LES predictions obtained using the same numerical set-up. It was shown that EWA-HTLES successfully drives the RANS-to-LES transition in such complex configurations exhibiting unsteady flow features and important cyclic geometrical deformations. It switched from the RANS mode at the walls to LES in the core region of the cylinder, allowing a better prediction of unsteady phenomena including the evolution of the overall tumble characteristics and phenomena associated to cyclic variability. The EWA-HTLES results were shown to be comparable to those predicted by LES, and superior to RANS.The performed developments and obtained results open encouraging perspectives for the application of this hybrid RANS/LES method in industrial configurations involving non-stationary conditions and in particular moving boundaries.

Download or read book Progress on Meshless Methods written by A. J. M. Ferreira and published by Springer Science & Business Media. This book was released on 2008-11-23 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years meshless/meshfree methods have gained considerable attention in engineering and applied mathematics. The variety of problems that are now being addressed by these techniques continues to expand and the quality of the results obtained demonstrates the effectiveness of many of the methods currently available. The book presents a significant sample of the state of the art in the field with methods that have reached a certain level of maturity while also addressing many open issues. The book collects extended original contributions presented at the Second ECCOMAS Conference on Meshless Methods held in 2007 in Porto. The list of contributors reveals a fortunate mix of highly distinguished authors as well as quite young but very active and promising researchers, thus giving the reader an interesting and updated view of different meshless approximation methods and their range of applications. The material presented is appropriate for researchers, engineers, physicists, applied mathematicians and graduate students interested in this active research area.

Download or read book MEGADESIGN and MegaOpt German Initiatives for Aerodynamic Simulation and Optimization in Aircraft Design written by Norbert Kroll and published by Springer Science & Business Media. This book was released on 2009-11-18 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains results of the German CFD initiative MEGADESIGN which combines CFD development activities from DLR, universities and aircraft industry. Based on the DLR flow solvers FLOWer and TAU the main objectives of the four-years project is to ensure the prediction accuracy with a guaranteed error bandwidth for certain aircraft configurations at design conditions, to reduce the simulation turn-around time for large-scale applications significantly, to improve the reliability of the flow solvers for full aircraft configurations in the complete flight regime, to extend the flow solvers to allow for multidisciplinary simulations and to establish numerical shape optimization as a vital tool within the aircraft design process. This volume highlights recent improvements and enhancements of the flow solvers as well as new developments with respect to aerodynamic and multidisciplinary shape optimization. Improved numerical simulation capabilities are demonstrated by several industrial applications.

Download or read book Numerical Simulation Technology of Aerodynamic Processes and Its Applications in Rocket Engine Problems written by G. Krulle and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Innovative 3D CFD Approach towards Virtual Development of Internal Combustion Engines written by Marco Chiodi and published by Springer Science & Business Media. This book was released on 2011-03-07 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the engine development process, simulation and predictive programs have continuously gained in reliance. Due to the complexity of future internal combustion engines the application of simulation programs towards a reliable “virtual engine development” is a need that represents one of the greatest challenges. Marco Chiodi presents an innovative 3D-CFD-tool, exclusively dedicated and optimized for the simulation of internal combustion engines. Thanks to improved or newly developed 3D-CFD-models for the description of engine processes, this tool ensures an efficient and reliable calculation also by using coarse 3D-CFD-meshes. Based on this approach the CPU-time can be reduced up to a factor 100 in comparison to traditional 3D-CFD-simulations. In addition an integrated and automatic “evaluation tool” establishes a comprehensive analysis of the relevant engine parameters. Due to the capability of a reliable “virtual development” of full-engines, this fast response 3D-CFD-tool makes a major contribution to the engine development process. Südwestmetall-Förderpreis 2010

Download or read book Recent Development of Aerodynamic Design Methodologies written by Kozo Fujii and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Fluid Dynamics (CFD) has made remarkable progress in the last two decades and is becoming an important, if not inevitable, analytical tool for both fundamental and practical fluid dynamics research. The analysis of flow fields is important in the sense that it improves the researcher's understanding of the flow features. CFD analysis also indirectly helps the design of new aircraft and/or spacecraft. However, design methodologies are the real need for the development of aircraft or spacecraft. They directly contribute to the design process and can significantly shorten the design cycle. Although quite a few publications have been written on this subject, most of the methods proposed were not used in practice in the past due to an immature research level and restrictions due to the inadequate computing capabilities. With the progress of high-speed computers, the time has come for such methods to be used practically. There is strong evidence of a growing interest in the development and use of aerodynamic inverse design and optimization techniques. This is true, not only for aerospace industries, but also for any industries requiring fluid dynamic design. This clearly shows the matured engineering need for optimum aerodynamic shape design methodologies. Therefore, it seems timely to publish a book in which eminent researchers in this area can elaborate on their research efforts and discuss it in conjunction with other efforts.

Download or read book Simulation driven Aerodynamic Design Using Variable fidelity Models written by Leifur Leifsson and published by World Scientific. This book was released on 2015-01-09 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer simulations is a fundamental tool of the design process in many engineering disciplines including aerospace engineering. However, although high-fidelity numerical models are accurate, they can be computationally expensive with evaluation time for a single design as long as hours, days or even weeks. Simulation-driven design using conventional optimization techniques may be therefore prohibitive.This book explores the alternative: performing computationally efficient design using surrogate-based optimization, where the high-fidelity model is replaced by its computationally cheap but still reasonably accurate representation: a surrogate. The emphasis is on physics-based surrogates. Application-wise, the focus is on aerodynamics and the methods and techniques described in the book are demonstrated using aerodynamic shape optimization cases. Applications in other engineering fields are also demonstrated.State-of-the-art techniques and a depth of coverage never published before make this a unique and essential book for all researchers working in aerospace and other engineering areas and dealing with optimization, computationally expensive design problems, and simulation-driven design.

Download or read book Simulation and Optimization of Internal Combustion Engines written by Zhiyu Han and published by SAE International. This book was released on 2021-12-28 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simulation and Optimization of Internal Combustion Engines provides the fundamentals and up-to-date progress in multidimensional simulation and optimization of internal combustion engines. While it is impossible to include all the models in a single book, this book intends to introduce the pioneer and/or the often-used models and the physics behind them providing readers with ready-to-use knowledge. Key issues, useful modeling methodology and techniques, as well as instructive results, are discussed through examples. Readers will understand the fundamentals of these examples and be inspired to explore new ideas and means for better solutions in their studies and work. Topics include combustion basis of IC engines, mathematical descriptions of reactive flow with sprays, engine in-cylinder turbulence, fuel sprays, combustions and pollutant emissions, optimization of direct-injection gasoline engines, and optimization of diesel and alternative fuel engines.

Download or read book Progress and Challenges in CFD Methods and Algorithms written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Fluid Dynamics Panel. Symposium and published by . This book was released on 1996 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in meshless methods written by Jan Sladek and published by . This book was released on 2006 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Meshless methods belong to one of the most progressivelydeveloped part of computational mechanics. These methods are increasingly applied to many fields of engineering and sciences. Therefore, the number of new results in this field is growing significantly during the past few years. It is a natural need to organize a conference in this subject to discuss about further developments of meshless methods. The first ICCES meshless symposium held in High Tatras, Slovakia brought together both mathematicians and engineers interested in developing new progressive computational methods. The best selected lectures from the symposium are collected in this book in their extended form.

Download or read book Development and Use of a Multi purpose Simulation Framework for Internal Combustion Engine Design written by Evangelos Karvounis and published by . This book was released on 1991 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Simulations and Applications written by Jianping Zhu and published by IntechOpen. This book was released on 2011-10-26 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to introduce researchers and graduate students to a broad range of applications of computational simulations, with a particular emphasis on those involving computational fluid dynamics (CFD) simulations. The book is divided into three parts: Part I covers some basic research topics and development in numerical algorithms for CFD simulations, including Reynolds stress transport modeling, central difference schemes for convection-diffusion equations, and flow simulations involving simple geometries such as a flat plate or a vertical channel. Part II covers a variety of important applications in which CFD simulations play a crucial role, including combustion process and automobile engine design, fluid heat exchange, airborne contaminant dispersion over buildings and atmospheric flow around a re-entry capsule, gas-solid two phase flow in long pipes, free surface flow around a ship hull, and hydrodynamic analysis of electrochemical cells. Part III covers applications of non-CFD based computational simulations, including atmospheric optical communications, climate system simulations, porous media flow, combustion, solidification, and sound field simulations for optimal acoustic effects.

Download or read book Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms written by J J Williams and published by Springer Science & Business Media. This book was released on 2012-10-19 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern design methods of Automotive Cam Design require the computation of a range of parameters. This book provides a logical sequence of steps for the derivation of the relevant equations from first principles, for the more widely used cam mechanisms. Although originally derived for use in high performance engines, this work is equally applicable to the design of mass produced automotive and other internal combustion engines. This work may also be applicable for cams used in other areas such as printing and packaging machinery. Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms provides the equations necessary for the design of cam lift curves with an associated smooth acceleration curve. The equations are derived for the kinematics and kinetics of all the mechanisms considered, together with those for cam curvature and oil entrainment velocity. This permits the cam shape, all loads and contact stresses to be evaluated, and the relevant tribology to be assessed. The effects of asymmetry on the manufacture of cams for finger follower and offset translating curved followers is described, and methods for transformation of cam shape data to that for a radial translating follower are given. This permits the manufacture and inspection by a wider range of CNC machines. The calculation of unsteady camshaft torques is described and an outline given for evaluation of the components for the lower engine orders. Although the theory, use and design, of reactive pendulum dampers are well documented elsewhere, these subjects have also been considered for completeness. The final chapter presents analysis of push rod mechanisms, including a four bar chain mechanism, which is more robust Written both as a reference for practising automotive design and development Engineers, and a text book for automotive engineering students, Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms gives readers a thorough introduction into the design of automotive cam mechanisms, including much material not previously published.

Download or read book Numerical Simulations of Incompressible Flows written by M. M. Hafez and published by World Scientific. This book was released on 2003 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Consists mainly of papers presented at a workshop ... held in Half Moon Bay, California, June 19-21, 2001 ... to honor Dr. Dochan Kwak on the occasion of his 60th birthday ... organized by M. Hafez of University of California Davis and Dong Ho Lee of Seoul National University"--Dedication, p. ix.

Download or read book Computational Heat Transfer written by Yogesh Jaluria and published by Routledge. This book was released on 2017-10-19 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition updated the material by expanding coverage of certain topics, adding new examples and problems, removing outdated material, and adding a computer disk, which will be included with each book. Professor Jaluria and Torrance have structured a text addressing both finite difference and finite element methods, comparing a number of applicable methods.

Download or read book Smoothed Particle Hydrodynamics written by Gui-Rong Liu and published by World Scientific. This book was released on 2003 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first-ever book on smoothed particle hydrodynamics (SPH) and its variations, covering the theoretical background, numerical techniques, code implementation issues, and many novel and interesting applications. It contains many appealing and practical examples, including free surface flows, high explosive detonation and explosion, underwater explosion and water mitigation of explosive shocks, high velocity impact and penetration, and multiple scale simulations coupled with the molecular dynamics method. An SPH source code is provided and coupling of SPH and molecular dynamics is discussed for multiscale simulation, making this a friendly book for readers and SPH users.