Download or read book Stabilization and Blowout of Gaseous and Spray Jet Flames written by Kevin M. Lyons and published by . This book was released on 2001 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research program to focus on experimental work in lifted flames (gaseous and spray) has been initiated. In particular, the group is interested in the similarities of spray and gaseous lifted-flame structures, similarities and differences in apparent stabilization phenomena, the role of mixing in each and blowout phenomena. Discussed in this report are the details of experimental findings in gaseous combustion and proposed experiments primarily in spray combustion and how the information and data to be obtained aids in understanding the physics of flame stabilization in general.
Download or read book Army Research Office and Air Force Office of Scientific Research 2002 Contractors Meeting in Chemical Propulsion written by David M. Mann and published by . This book was released on 2002 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstracts are given for 6.1 basic research in chemical propulsion sponsored by the Army Research Office and the Air Force Office of Scientific Research.
Download or read book Stabilization and Dynamic of Premixed Swirling Flames written by Paul Palies and published by Academic Press. This book was released on 2020-07-03 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stabilization and Dynamic of Premixed Swirling Flames: Prevaporized, Stratified, Partially, and Fully Premixed Regimes focuses on swirling flames in various premixed modes (stratified, partially, fully, prevaporized) for the combustor, and development and design of current and future swirl-stabilized combustion systems. This includes predicting capabilities, modeling of turbulent combustion, liquid fuel modeling, and a complete overview of stabilization of these flames in aeroengines. The book also discusses the effects of the operating envelope on upstream fresh gases and the subsequent impact of flame speed, combustion, and mixing, the theoretical framework for flame stabilization, and fully lean premixed injector design. Specific attention is paid to ground gas turbine applications, and a comprehensive review of stabilization mechanisms for premixed, partially-premixed, and stratified premixed flames. The last chapter covers the design of a fully premixed injector for future jet engine applications. Features a complete view of the challenges at the intersection of swirling flame combustors, their requirements, and the physics of fluids at work Addresses the challenges of turbulent combustion modeling with numerical simulations Includes the presentation of the very latest numerical results and analyses of flashback, lean blowout, and combustion instabilities Covers the design of a fully premixed injector for future jet engine applications
Download or read book Studies in Flame Propagation and Blowout written by and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report outlines our most recent research work on the topic of upstream flame propagation and blowout in hydrocarbon jet flames. Outlined specifically are the recent elements of the research for the study of fundamental structural characteristics of jet flames and related flame/spray/flow interactions. Specifically, the scope encompasses further optical imaging investigations of flame structure and behavior, and an exploratory study of the effects of co-flow air on extinction and blowout. Analysis of the results of experiments to understand the behavior of gaseous and spray flame counterparts is the main deliverable. The methodology of the research is largely experimental, emphasizing the application of optical diagnostic techniques to instantaneously visualize reaction zones. The main efforts to report since the last update are the following: 1) Studies have been launched that examine the development of combustion in an initially non-reacting methane jet after ignition at a downstream location and 2) The driving mechanisms that cause jet-flame blowout, particularly in the presence of air co-flow, have been investigated. This work attempts to determine the role of fuel velocity and air co-flow in the blowout phenomenon.
Download or read book Effects of Leading Edge Flame Behavior on Flame Stabilization and Blowout written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this work was to identify the mechanisms that effect stabilization of hydrocarbon jet flames. Methane, nitrogen, and co-flowing air were regulated and directed through a burner that created fully-developed fuel flow with concurrent air. The behavior of the reaction zone at the leading-edge was analyzed from digital images obtained from a camera optimally positioned to capture the movements of the entire flame front. Low Reynolds number flows allowed for the investigation of hysteretic behavior. The hysteresis regime refers to the situation where the jet flame has dual positions favorable to flame stabilization: attached and lifted. Results indicate that flame height in hysteresis is significantly impacted by high velocities of co-flow and that past a critical value a local minimum will be created. Fully turbulent lifted flames were also studied to determine the fluctuations in the height of lifted methane flames in the presence of air co-flow. The partially-premixed flame front of the lifted flame fluctuates in the axial direction, with the fluctuations becoming greater in flames stabilized further downstream. These fluctuations are also observed in flames where blowout is imminent. The height and rate of these fluctuations are studied with respect to average height, flow velocities, and Reynolds number. Additionally, the mechanisms that cause jet-flame blowout, particularly in the presence of air co-flow, are not completely understood. Two types of experiments are described, and the data report that a predictor of blowout is the prior disappearance of the axially-oriented flame branch which is consistently witnessed despite a turbulent flameÃØâ'Ơâ"Øs inherent variable behavior. The conclusions are supported by experiments with nitrogen-diluted flames. A blowout parameter is also calculated for methane flames in co-flow and diluted methane flames that can be used to predict at what flow velocities blowout will occur. This work analyzes flames near the bu.
Download or read book Effects of Pilot Flame Stabilization on Gas Jet Flames in a Cross flow written by S. R. Gollahalli and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stabilization Zone Structure in Jet Diffusion Flames from Liftoff to Blowout written by T.H. Chen and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stability and Blowout Behavior of Jet Flames in Oblique Air Flows written by Jonathan Nicholas Gomes and published by . This book was released on 2011 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Physics written by Chung K. Law and published by Cambridge University Press. This book was released on 2010-08-23 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate-level text incorporates these advances in a comprehensive treatment of the fundamental principles of combustion physics. The presentation emphasises analytical proficiency and physical insight, with the former achieved through complete, though abbreviated, derivations at different levels of rigor, and the latter through physical interpretations of analytical solutions, experimental observations, and computational simulations. Exercises are mostly derivative in nature in order to further strengthen the student's mastery of the theory. Implications of the fundamental knowledge gained herein on practical phenomena are discussed whenever appropriate. These distinguishing features provide a solid foundation for an academic program in combustion science and engineering.
Download or read book The Structure and Stability of Nonpremixed Gas Jet Flames written by Rong Fung Huang and published by . This book was released on 1987 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduced Kinetic Mechanisms for Applications in Combustion Systems written by Norbert Peters and published by Springer Science & Business Media. This book was released on 2008-09-11 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: In general, combustion is a spatially three-dimensional, highly complex physi co-chemical process oftransient nature. Models are therefore needed that sim to such a degree that it becomes amenable plify a given combustion problem to theoretical or numerical analysis but that are not so restrictive as to distort the underlying physics or chemistry. In particular, in view of worldwide efforts to conserve energy and to control pollutant formation, models of combustion chemistry are needed that are sufficiently accurate to allow confident predic tions of flame structures. Reduced kinetic mechanisms, which are the topic of the present book, represent such combustion-chemistry models. Historically combustion chemistry was first described as a global one-step reaction in which fuel and oxidizer react to form a single product. Even when detailed mechanisms ofelementary reactions became available, empirical one step kinetic approximations were needed in order to make problems amenable to theoretical analysis. This situation began to change inthe early 1970s when computing facilities became more powerful and more widely available, thereby facilitating numerical analysis of relatively simple combustion problems, typi cally steady one-dimensional flames, with moderately detailed mechanisms of elementary reactions. However, even on the fastest and most powerful com puters available today, numerical simulations of, say, laminar, steady, three dimensional reacting flows with reasonably detailed and hence realistic ki netic mechanisms of elementary reactions are not possible.
Download or read book Ignition and Flame Stabilization of Stream of Combustible Gaseous Mixtures by Hot Jet written by Hiroshi Tsuji and published by . This book was released on 1960 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lean Blowout Mitigation in Swirl Stabilized Premixed Flames written by Shashvat Prakash and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lean, premixed combustion offers a practical approach for reducing nitrogen oxide (NOx) emissions, but increases the risk of lean blowout (LBO) in gas turbines. Active control techniques are therefore sought which can stabilize a lean flame and prevent LBO. The present work has resulted in the development of flame detection, dynamic modeling, blowout margin estimation, and actuation and control techniques. The flame's acoustic emissions were bandpass filtered at select frequencies to detect localized extinction events, which were found to increase in number near LBO. The lean flame was also found to intermittently burst into a transient 'tornado' configuration in which the flame's inner recirculation zone would collapse. The localized extinctions were dynamically linked to the tornado bursts using a linear, first order model. The model was subsequently applied to predict tornado bursts based on optically detected localized extinction events. It was found that both localized extinctions and tornado bursts are by themselves Poisson processes; the exponential distribution of their spacing times could be used to determine blowout probability. Blowout mitigation was achieved by redistributing the fuel flow between the annular swirlers and central preinjection pilot, both of which were premixed. Rule-based and lead-lag control architectures were developed and validated.
Download or read book Lean Combustion written by Derek Dunn-Rankin and published by Academic Press. This book was released on 2016-07-01 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lean Combustion: Technology and Control, Second Edition outlines and explains the latest advances in lean combustion technology and systems. Combustion under sufficiently fuel-lean conditions can have the desirable attributes of high efficiency and low emissions. The book offers readers both the fundamentals and latest developments in how lean burn (broadly defined) can increase fuel economy and decrease emissions, while still achieving desired power output and performance. This volume brings together research and design of lean combustion systems across the technology spectrum in order to explore the state-of-the-art in lean combustion. Readers will learn about advances in the understanding of ultra-lean fuel mixtures and how new types of burners and approaches to managing heat flow can reduce problems often found with lean combustion (such as slow, difficult ignition and frequent flame extinction). This book offers abundant references and examples of real-world applications. New to this edition are significantly revised chapters on IC engines and stability/oscillations, and new case studies and examples. Written by a team of experts, this contributed reference book aims to teach its reader to maximize efficiency and minimize both economic and environmental costs. Presents a comprehensive collection of lean burn technology across potential applications, allowing readers to compare and contrast similarities and differences Provides an extensive update on IC engines including compression ignition (diesel), spark ignition, and homogeneous charge compression ignition (HCCI) Includes an extensive revision to the Stability/Oscillations chapter Includes use of alternative fuels such as biogas and hydrogen for relevant technologies Covers new developments in lean combustion using high levels of pre-heat and heat recirculating burners, as well as the active control of lean combustion instabilities
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1948 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Fire and Combustion Systems 1993 written by Bakhtier Farouk and published by . This book was released on 1993 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Approaches for Clean Combustion in Gas Turbines written by Medhat A. Nemitallah and published by Springer Nature. This book was released on 2020-03-24 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the development of novel combustion approaches and burner designs for clean power generation in gas turbines. It shows the reader how to control the release of pollutants to the environment in an effort to reduce global warming. After an introduction to global warming issues and clean power production for gas turbine applications, subsequent chapters address premixed combustion, burner designs for clean power generation, gas turbine performance, and insights on gas turbine operability. Given its scope, the book can be used as a textbook for graduate-level courses on clean combustion, or as a reference book to accompany compact courses for mechanical engineers and young researchers around the world.
