Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Lean Blowout Mitigation In Swirl Stabilized Premixed Flames
Download Lean Blowout Mitigation In Swirl Stabilized Premixed Flames full books in PDF, epub, and Kindle. Read online Lean Blowout Mitigation In Swirl Stabilized Premixed Flames ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Lean Blowout Mitigation in Swirl Stabilized Premixed Flames by : Shashvat Prakash
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.
Book Synopsis Stabilization and Dynamic of Premixed Swirling Flames by : Paul Palies
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
Book Synopsis Combustion Dynamics of Swirl-stabilized Lean Premixed Flames in an Acoustically-driven Environment by : Yun Huang
Download or read book Combustion Dynamics of Swirl-stabilized Lean Premixed Flames in an Acoustically-driven Environment written by Yun Huang and published by . This book was released on 2008 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a similar fashion, increasing the pressure was found to alter the flame shape and flame extent, but the thermo-acoustic coupling and induced large scale structure persisted to 0.34MPa, the highest pressure tested.
Book Synopsis Swirl-stabilized Lean-premixed Flame Combustion Dynamics: An Experimental Investigation of Flame Stabilization, Flame Dynamics and Combustion Instability Control Strategies by : Rajavasanth Rajasegar
Download or read book Swirl-stabilized Lean-premixed Flame Combustion Dynamics: An Experimental Investigation of Flame Stabilization, Flame Dynamics and Combustion Instability Control Strategies written by Rajavasanth Rajasegar and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Flame Response Mechanisms and Their Interaction in a Lean Premixed Swirl-stabilized Gas Turbine Combustor by : Brian Jones
Download or read book Flame Response Mechanisms and Their Interaction in a Lean Premixed Swirl-stabilized Gas Turbine Combustor written by Brian Jones and published by . This book was released on 2011 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experimental Study of Lean Blowout with Hydrogen Addition in a Swirl-stabilized Premixed Combustor by : Shengrong Zhu
Download or read book Experimental Study of Lean Blowout with Hydrogen Addition in a Swirl-stabilized Premixed Combustor written by Shengrong Zhu and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Novel Combustion Concepts for Sustainable Energy Development by : Avinash K Agarwal
Download or read book Novel Combustion Concepts for Sustainable Energy Development written by Avinash K Agarwal and published by Springer. This book was released on 2014-12-19 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises research studies of novel work on combustion for sustainable energy development. It offers an insight into a few viable novel technologies for improved, efficient and sustainable utilization of combustion-based energy production using both fossil and bio fuels. Special emphasis is placed on micro-scale combustion systems that offer new challenges and opportunities. The book is divided into five sections, with chapters from 3-4 leading experts forming the core of each section. The book should prove useful to a variety of readers, including students, researchers, and professionals.
Book Synopsis On the Lean Blowout Limit of Premixed Flames by : E. Gutmark
Download or read book On the Lean Blowout Limit of Premixed Flames written by E. Gutmark and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Thermoacoustic Instability by : R. I. Sujith
Download or read book Thermoacoustic Instability written by R. I. Sujith and published by Springer Nature. This book was released on 2021-12-14 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book systematically presents the consolidated findings of the phenomenon of self-organization observed during the onset of thermoacoustic instability using approaches from dynamical systems and complex systems theory. Over the last decade, several complex dynamical states beyond limit cycle oscillations such as quasiperiodicity, frequency-locking, period-n, chaos, strange non-chaos, and intermittency have been discovered in thermoacoustic systems operated in laminar and turbulent flow regimes. During the onset of thermoacoustic instability in turbulent systems, an ordered acoustic field and large coherent vortices emerge from the background of turbulent combustion. This emergence of order from disorder in both temporal and spatiotemporal dynamics is explored in the contexts of synchronization, pattern formation, collective interaction, multifractality, and complex networks. For the past six decades, the spontaneous emergence of large amplitude, self-sustained, tonal oscillations in confined combustion systems, characterized as thermoacoustic instability, has remained one of the most challenging areas of research. The presence of such instabilities continues to hinder the development and deployment of high-performance combustion systems used in power generation and propulsion applications. Even with the advent of sophisticated measurement techniques to aid experimental investigations and vast improvements in computational power necessary to capture flow physics in high fidelity simulations, conventional reductionist approaches have not succeeded in explaining the plethora of dynamical behaviors and the associated complexities that arise in practical combustion systems. As a result, models and theories based on such approaches are limited in their application to mitigate or evade thermoacoustic instabilities, which continue to be among the biggest concerns for engine manufacturers today. This book helps to overcome these limitations by providing appropriate methodologies to deal with nonlinear thermoacoustic oscillations, and by developing control strategies that can mitigate and forewarn thermoacoustic instabilities. The book is also beneficial to scientists and engineers studying the occurrence of several other instabilities, such as flow-induced vibrations, compressor surge, aeroacoustics and aeroelastic instabilities in diverse fluid-mechanical environments, to graduate students who intend to apply dynamical systems and complex systems approach to their areas of research, and to physicists who look for experimental applications of their theoretical findings on nonlinear and complex systems.
Book Synopsis Lean Blowout Dynamics for Premixed Bluff-body Flames by : Anthony J. Morales
Download or read book Lean Blowout Dynamics for Premixed Bluff-body Flames written by Anthony J. Morales and published by . This book was released on 2020 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lean blowout is experimentally investigated for premixed bluff-body flames under various inlet velocity conditions, pressure gradients, and turbulence conditions to study the influence of fluid mechanics on the lean blowout process. A premixed combustion facility paired with a bluff-body flame stabilizer is used for the study. For all experiments, lean blowout is induced by temporally decreasing the fuel flow rate into the reactant stream. A suite of high-speed optical diagnostics are simultaneously employed to capture the transient blowout process: particle image velocimetry (PIV), stereoscopic PIV, and C2*/CH* chemiluminescence imaging. These diagnostics allow for the instantaneous flame boundary, velocity fields, equivalence ratios, and local flame strain rates to be evaluated during blowout. For all testing conditions, the results show that the blowout process is highly coupled to the fluid mechanics within the reacting domain and blowout is driven from flame-flow interactions (i.e. flame-vorticity interactions or flame-turbulence interactions). The results also demonstrate that altering the vorticity dynamics or turbulence conditions within the reacting domain can profoundly augment or attenuate the blowout process.
Book Synopsis Stabilization and Blowout Characteristics of Lean Premixed Turbulent Flames Behind a Backward-facing Step in a Rectangular Combustor with Heated Propane-air Mixtures by :
Download or read book Stabilization and Blowout Characteristics of Lean Premixed Turbulent Flames Behind a Backward-facing Step in a Rectangular Combustor with Heated Propane-air Mixtures written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Turbulent Premixed Flames by : Nedunchezhian Swaminathan
Download or read book Turbulent Premixed Flames written by Nedunchezhian Swaminathan and published by Cambridge University Press. This book was released on 2011-04-25 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: A work on turbulent premixed combustion is important because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.
Book Synopsis A Study of Lean Premixed Swirl-stabilized Combustion of Gaseous Alternative Fuels by : Donald McKinley Wicksall
Download or read book A Study of Lean Premixed Swirl-stabilized Combustion of Gaseous Alternative Fuels written by Donald McKinley Wicksall and published by . This book was released on 2004 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Unsteady Combustor Physics by : Tim C. Lieuwen
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.
Book Synopsis Combustion for Power Generation and Transportation by : Avinash Kumar Agarwal
Download or read book Combustion for Power Generation and Transportation written by Avinash Kumar Agarwal and published by Springer. This book was released on 2017-01-20 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research monograph presents both fundamental science and applied innovations on several key and emerging technologies involving fossil and alternate fuel utilization in power and transport sectors from renowned experts in the field. Some of the topics covered include: autoignition in laminar and turbulent nonpremixed flames; Langevin simulation of turbulent combustion; lean blowout (LBO) prediction through symbolic time series analysis; lasers and optical diagnostics for next generation IC engine development; exergy destruction study on small DI diesel engine; and gasoline direct injection. The book includes a chapter on carbon sequestration and optimization of enhanced oil and gas recovery. The contents of this book will be useful to researchers and professionals working on all aspects on combustion.
Book Synopsis Lean Blowout and Its Robust Sensing in Swirl Combustors by : Ravi K. Bompelly
Download or read book Lean Blowout and Its Robust Sensing in Swirl Combustors written by Ravi K. Bompelly and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lean combustion is increasingly employed in both ground-based gas turbines and aircraft engines for minimizing NOx emissions. Operating under lean conditions increases the risk of Lean Blowout (LBO). Thus LBO proximity sensors, combined with appropriate blowout prevention systems, have the potential to improve the performance of engines. In previous studies, atmospheric pressure, swirl flames near LBO have been observed to exhibit partial extinction and re-ignition events called LBO precursors. Detecting these precursor events in optical and acoustic signals with simple non-intrusive sensors provided a measure of LBO proximity. This thesis examines robust LBO margin sensing approaches, by exploring LBO precursors in the presence of combustion dynamics and for combustor operating conditions that are more representative of practical combustors, i.e., elevated pressure and preheat temperature operation. To this end, two combustors were used: a gas-fueled, atmospheric pressure combustor that exhibits pronounced combustion dynamics under a wide range of lean conditions, and a low NOx emission liquid-fueled lean direct injection (LDI) combustor, operating at elevated pressure and preheat temperature. In the gas-fueled combustor, flame extinction and re-ignition LBO precursor events were observed in the presence of strong combustion dynamics, and were similar to those observed in dynamically stable conditions. However, the signature of the events in the raw optical signals have different characteristics under various operating conditions. Low-pass filtering and a single threshold-based event detection algorithm provided robust precursor sensing, regardless of the type or level of dynamic instability. The same algorithm provides robust event detection in the LDI combustor, which also exhibits low level dynamic oscillations. Compared to the gas-fueled combustor, the LDI events have weaker signatures, much shorter durations, but considerably higher occurrence rates. The disparity in precursor durations is due to a flame mode switch that occurs during precursors in the gas-fueled combustor, which is absent in the LDI combustor. Acoustic sensing was also investigated in both the combustors. Low-pass filtering is required to reveal a precursor signature under dynamically unstable conditions in the gas-fueled combustor. On the other hand in the LDI combustor, neither the raw signals nor the low-pass filtered signals reveal precursor events. The failure of acoustic sensing is attributed in part to the lower heat release variations, and the similarity in time scales for the precursors and dynamic oscillations in the LDI combustor. In addition, the impact of acoustic reflections from combustor boundaries and transducer placement was addressed by modeling reflections in a one-dimensional combustor geometry with an impedance jump caused by the flame. Implementing LBO margin sensors in gas turbine engines can potentially improve time response during deceleration transients by allowing lower operating margins. Occurrence of precursor events under transient operating conditions was examined with a statistical approach. For example, the rate at which the fuel-air ratio can be safely reduced might be limited by the requirement that at least one precursor occurs before blowout. The statistics governing the probability of a precursor event occurring during some time interval was shown to be reasonably modeled by Poisson statistics. A method has been developed to select a lower operating margin when LBO proximity sensors are employed, such that the lowered margin case provides a similar reliability in preventing LBO as the standard approach utilizing a more restrictive operating margin. Illustrative improvements in transient response and reliabilities in preventing LBO are presented for a model turbofan engine. In addition, an event-based, active LBO control approach for deceleration transients is also demonstrated in the engine simulation.
Book Synopsis Studies on Lean-blowout Characteristics of a Premixed Jet Flame by : Viswanath R. Katta
Download or read book Studies on Lean-blowout Characteristics of a Premixed Jet Flame written by Viswanath R. Katta and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress and Exposition, Houston, Texas - June 5-8, 1995.
