Download or read book Aerodynamics and Combustion of Axial Swirlers written by Yongqiang Fu and published by . This book was released on 2008 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multipoint lean direct injection (LDI) concept was introduced recently in non-premixed combustion to obtain both low NOx emissions and good combustion stability. In this concept, a key feature is the injection of finely atomized fuel into the high-swirling airflow at the combustor dome that provides a homogenous, lean fuel-air mixture. In order to achieve the fine atomization and mixing of the fuel and air quickly and uniformly, a good swirler design should be studied. The focus of this dissertation is to investigate the aerodynamics and combustion of the swirling flow field in a multipoint lean direct injector combustor. A helical axial-vaned swirler with a short internal convergent-divergent venturi was used. Swirlers with various vane angles and fuel nozzle insertion lengths have been designed. Three non-dimensional parameter effects on non-reacting, swirling flow field were studied: swirler number, confinement ratio and Reynolds number. Spray and combustion characteristics on the single swirler were studied to understand the mechanism of fuel-air mixing in this special configuration. Multi-swirler interactions were studied by measuring the confined flow field of a multipoint swirler array with different configurations. Two different swirler arrangements were investigated experimentally, which include a co-swirling array and a counter-swirling array. In order to increase the range of stability of multipoint LDI combustors, an improved design were also conducted. The results show that the degree of swirl and the level of confinement have a clear impact on the mean and turbulent flow fields. The swirling flow fields may also change significantly with the addition of a variety of simulated fuel nozzle insertion lengths. The swirler with short insertion has the stronger swirling flow as compared with the long insertion swirler. Reynolds numbers, with range of current study, will not alter mean and turbulent properties of generated flows. The reaction of the spray dramatically changes the gas phase velocity distribution, while the convergent-divergent nozzle strongly affects the spray velocity profiles. The multipoint flow field has a very complicated structure, especially for the flow structure near the swirler exit, where very strong interactions exit among the adjacent swirlers. Multipoint swirler arrays with the recessed center swirler will alter flow structure significantly. There is a short strong central recirculation zone in both co-swirler and counter-swirler recessed arrays, which may increase the operability range of the multipoint swirl-venturi LDI combustor.
Download or read book Combustor Aerodynamics written by Yehia A. Eldrainy and published by Penerbit UTM Press. This book was released on 2012 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the new innovation of gas turbine swirler. The novel swirler is a multiple entry swirler which allows the swirl number to vary on the same value of Reynolds number, by regulating the ratio between the axial and tangential flow momentum. Three–dimensional turbulence and isothermal flow characteristics of an abrupt combustor model with different type of swirler (axial, radial and multiple inlet) were simulated with Reynolds–Averaged Navier–Stokes (RANS) using ANSYS Fluent 12 software. Results of the different turbulence models used in swirling flow were reviewed and compared. The different swirler’ aerodynamic performance was investigated through Computational Fluid Dynamics (CFD) simulations. The aerodynamics performance includes shape and size of the Central Recirculation Zone (CRZ), turbulence intensity and pressure losses. It was found that the size of then CRZ and turbulence strength is directly proportional to the tangential axial air flow rate ratio. Therefore, proper selection of a swirler is needed to enhance combustor performance and to reduce exhaust emissions.
Download or read book Combustion Aerodynamics written by János Miklós Beér and published by . This book was released on 1983 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Analysis of Multi Swirler Aerodynamics written by Prachi Rojatkar and published by . This book was released on 2015 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Airflow through single- and multi-swirler arrangements for two swirler cup designs with radial-radial counter rotating vanes is computationally investigated using realizable k-e turbulence model on a grid ranging from 4 million (single swirler) to 36 million points (multi-swirler arrangements). Effect of swirler offset (distance between base wall of confinement and swirler exit plane) for a high swirl number (SN) swirler cup design arranged linearly with 0D, 0.02D and 0.04D offset, where D is swirler exit diameter is analyzed. Flow attaches to the base wall for lower offset conditions. Increasing offset leads to formation of distinct central toroidal recirculation zone (CTRZ) surrounded by jets with presence of recirculation between the adjacent jets and corner recirculation zone (CRZ) at walls. At constant offset, while the mass flow rate through each swirler is essentially the same, the flow field downstream of individual swirlers is quite different in a multi-swirler arrangement. At 0.02D offset a single swirler arrangement has a compact CTRZ with presence of a strong jet and CRZs whereas for the three swirler arrangement fluid entrainment into the central swirler jet leads to flow attachment to the base wall. For a five swirler arrangement the central swirler CTRZ length reduces. A 3x3 arrangement with all swirlers either arranged in a co-swirling or in a co/counter swirling pattern shows presence of a strong jet at each swirl cup along with formation of CTRZs for both arrangements. For co-swirling arrangement the CTRZs are longer in the axial direction with jet extending into the flow with much stronger velocity whereas alternate co/counter arrangement produces more swirler-to-swirler interactions. Changing offset to 0.31D, leads to formation of longer but narrower CTRZ with higher velocity gradient which can lead to better combustion performance. Deflection of the near wall swirler CTRZ is observed for alternate co/counter arrangement due to opposing flow from centermost swirler whereas these CTRZs are more or less symmetric in co swirling arrangement. Effect of flare geometry is studied for low SN swirl cup. Maximum positive axial velocity is comparatively higher while tangential velocity is substantially higher in presence of a flare very close to the swirler exit. For no flare case the tangential velocity variation is mostly due to the outer secondary flow as inner primary flow is rather weak resulting in overall weaker swirl that can adversely affect flame anchoring and combustion performance. Placement of a dummy nozzle at three different placement locations is analyzed. Without a nozzle a strong CTRZ is formed that extends inside the swirler. Placing the dummy nozzle in the region where the primary and secondary path flow merges is found to be the most advantageous as it leads to a strong and compact CTRZ that does not extend inside the swirler geometry. Results presented here show that small changes in a geometric feature of a multi-swirler array can lead to major differences in the resulting flow field. These factors should be carefully considered in design and testing of gas turbine combustors.
Download or read book Coarse Grained Simulation and Turbulent Mixing written by Fenando F. Grinstein and published by Cambridge University Press. This book was released on 2016-06-30 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews our current understanding of the subject. For graduate students and researchers in computational fluid dynamics and turbulence.
Download or read book Swirling Flows and Flames written by Toufik Boushaki and published by BoD – Books on Demand. This book was released on 2019-06-26 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Swirl flows are used in a wide range of industrial applications. In non-reacting cases, examples of applications include vortex amplifiers and reactors, heat exchangers, jet pumps, and cyclone separators. In reacting cases, swirlers are widely used in combustion systems, such as gas turbines, industrial furnaces, boilers, gasoline and diesel engines, and many other practical heating devices. Effects of using swirl on flow and combustion are significant and varied, and concern, for example, aerodynamics, mixing, flame stability, intensity of combustion, and pollutant emissions. The purpose of this book is to present recent research efforts to understand and characterize swirling flows of different types and in different applications. These include gaseous, liquid, and solid fuels in order to enhance combustion systems and their energy efficiency. Swirl flows are very complex and the studies proposed in this project are based on different means, including theoretical calculations, numerical modeling, and experimental measurements.
Download or read book Aerothermodynamics of Aircraft Engine Components written by Gordon C. Oates and published by AIAA. This book was released on 1985 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Design and R & D engineers and students will value the comprehensive, meticulous coverage in this volume. Beginning with the basic principles and concepts of aeropropulsion combustion, chapters explore specific processes, limitations, and analytical methods as they bear on component design.
Download or read book GAS Turbine Combustion Second Edition written by Arthur H. Lefebvre and published by CRC Press. This book was released on 1998-09-01 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This revised edition provides understanding of the basic physical, chemical, and aerodynamic processes associated with gas turbine combustion and their relevance and application to combustor performance and design. It also introduces the many new concepts for ultra-low emissions combustors, and new advances in fuel preparation and liner wall-cooling techniques for their success. It details advanced and practical approaches to combustor design for the clean burning of alternative liquid fuels derived from oil shades, tar sands, and coal. Additional topics include diffusers, combustion performance fuel injection, combustion noise, heat transfer, and emissions.
Download or read book Aerodynamics Mixing Characteristics and Combustion Performance of Non swirl Multi jet Shear Layer Flow written by Azeman Mustafa and published by . This book was released on 1999 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Turbine Combustion written by Arthur H. Lefebvre and published by CRC Press. This book was released on 2010-04-26 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting the developments in gas turbine combustion technology that have occurred in the last decade, Gas Turbine Combustion: Alternative Fuels and Emissions, Third Edition provides an up-to-date design manual and research reference on the design, manufacture, and operation of gas turbine combustors in applications ranging from aeronautical to po
Download or read book Applied Computational Fluid Dynamics and Turbulence Modeling written by Sal Rodriguez and published by Springer Nature. This book was released on 2019-12-06 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique text provides engineering students and practicing professionals with a comprehensive set of practical, hands-on guidelines and dozens of step-by-step examples for performing state-of-the-art, reliable computational fluid dynamics (CFD) and turbulence modeling. Key CFD and turbulence programs are included as well. The text first reviews basic CFD theory, and then details advanced applied theories for estimating turbulence, including new algorithms created by the author. The book gives practical advice on selecting appropriate turbulence models and presents best CFD practices for modeling and generating reliable simulations. The author gathered and developed the book’s hundreds of tips, tricks, and examples over three decades of research and development at three national laboratories and at the University of New Mexico—many in print for the first time in this book. The book also places a strong emphasis on recent CFD and turbulence advancements found in the literature over the past five to 10 years. Readers can apply the author’s advice and insights whether using commercial or national laboratory software such as ANSYS Fluent, STAR-CCM, COMSOL, Flownex, SimScale, OpenFOAM, Fuego, KIVA, BIGHORN, or their own computational tools. Applied Computational Fluid Dynamics and Turbulence Modeling is a practical, complementary companion for academic CFD textbooks and senior project courses in mechanical, civil, chemical, and nuclear engineering; senior undergraduate and graduate CFD and turbulence modeling courses; and for professionals developing commercial and research applications.
Download or read book Fundamentals and Technology of Combustion written by F El-Mahallawy and published by Elsevier. This book was released on 2002-07-10 with total page 863 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals and Technology of Combustion contains brief descriptions of combustion fundamental processes, followed by an extensive survey of the combustion research technology. It also includes mathematical combustion modeling of the processes covering mainly premixed and diffusion flames, where many chemical and physical processes compete in complex ways, for both laminar and turbulent flows. The combustion chemistry models that validate experimental data for different fuels are sufficiently accurate to allow confident predictions of the flame characteristics. This illustrates a unique bridge between combustion fundamentals and combustion technology, which provides a valuable technical reference for many engineers and scientists. Moreover, the book gives the reader sufficient background of basic engineering sciences such as chemistry, thermodynamics, heat transfer and fluid mechanics. The combustion research and mathematical models fit between small-scale laboratory burner flames, and large-scale industrial boilers, furnaces and combustion chambers. The materials have been collected from previous relevant research and some selected papers of the authors and co-workers, which have been presented mainly in different refereed journals, international conferences and symposia, thus providing a comprehensive collection. Furthermore, the book includes some of the many recent general correlations for the characteristics of laminar, turbulent, premixed and diffusion flames in an easily usable form. The authors believe that further progress in optimizing combustion performance and reducing polluting emissions can only be treated through understanding of combustion chemistry.
Download or read book Unsteady Combustor Physics written by Tim C. Lieuwen and published by Cambridge University Press. This book was released on 2012-08-27 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developing clean, sustainable energy systems is a pre-eminent issue of our time. Most projections indicate that combustion-based energy conversion systems will continue to be the predominant approach for the majority of our energy usage. Unsteady combustor issues present the key challenge associated with the development of clean, high-efficiency combustion systems such as those used for power generation, heating or propulsion applications. This comprehensive study is unique, treating the subject in a systematic manner. Although this book focuses on unsteady combusting flows, it places particular emphasis on the system dynamics that occur at the intersection of the combustion, fluid mechanics and acoustic disciplines. Individuals with a background in fluid mechanics and combustion will find this book to be an incomparable study that synthesises these fields into a coherent understanding of the intrinsically unsteady processes in combustors.
Download or read book Gas Turbines for Electric Power Generation written by S. Can Gülen and published by Cambridge University Press. This book was released on 2019-02-14 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: Everything you wanted to know about industrial gas turbines for electric power generation in one source with hard-to-find, hands-on technical information.
Download or read book Computation of Three Dimensional Complex Flows written by Michel Deville and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Der Sammelband enthält Beiträge einer Tagung über die Simulation von dreidimensionalen Flüssigkeiten. Sie geben einen Überblick über den Stand des Wissens auf dem Gebiet der numerischen Simulation der Turbulenz, angewandt auf eine weite Spanne von Problemen wie Aerodynamik, Nicht-Newtonsche Flüssigkeiten, Konvektion.This volume contains the material presented at the IMACS-COST Conference on CFD, Three-Dimensional Complex Flows, held in Lausanne (Switzerland), September 13 - 15, 1995. It gives an overview of the current state of numerical simulation and turbulence modelling applied to a wide range of fluid flow problems such as an example aerodynamics, non-Newtonian flows, transition, thermal convection.
Download or read book Combustion aerodynamics written by Janós M. Beér and published by . This book was released on 1983 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbine Aerodynamics written by Ronald H. Aungier and published by American Society of Mechanical Engineers. This book was released on 2006 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough description of actual, working aerodynamic design and analysis systems, for both axial-flow and radial-flow turbines. It describes the basic fluid dynamic and thermodynamic principles, empirical models and numerical methods used for the full range of procedures and analytical tools that an engineer needs for virtually any type of aerodynamic design or analysis activity for both types of turbine. The book includes sufficient detail for readers to implement all or part of the systems. The author provides practical and effective design strategies for applying both turbine types, which are illustrated by design examples. Comparisons with experimental results are included to demonstrate the prediction accuracy to be expected. This book is intended for practicing engineers concerned with the design and development of turbines and related machinery.
