Download or read book Combustion Noise written by Anna Schwarz and published by Springer Science & Business Media. This book was released on 2009-06-17 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: November, 2008 Anna Schwarz, Johannes Janicka In the last thirty years noise emission has developed into a topic of increasing importance to society and economy. In ?elds such as air, road and rail traf?c, the control of noise emissions and development of associated noise-reduction techno- gies is a central requirement for social acceptance and economical competitiveness. The noise emission of combustion systems is a major part of the task of noise - duction. The following aspects motivate research: • Modern combustion chambers in technical combustion systems with low pol- tion exhausts are 5 - 8 dB louder compared to their predecessors. In the ope- tional state the noise pressure levels achieved can even be 10-15 dB louder. • High capacity torches in the chemical industry are usually placed at ground level because of the reasons of noise emissions instead of being placed at a height suitable for safety and security. • For airplanes the combustion emissions become a more and more important topic. The combustion instability and noise issues are one major obstacle for the introduction of green technologies as lean fuel combustion and premixed burners in aero-engines. The direct and indirect contribution of combustion noise to the overall core noise is still under discussion. However, it is clear that the core noise besides the fan tone will become an important noise source in future aero-engine designs. To further reduce the jet noise, geared ultra high bypass ratio fans are driven by only a few highly loaded turbine stages.
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.
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.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2007 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 38th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 02 3850 02 3899 written by and published by . This book was released on 2002 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aero and Hydro Acoustics written by Genevieve Comte-Bellot and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Symposium "Aero-and Hydroacoustics" was held at the Ecole Centrale de Lyon, France, on 3rd - 6 July 1985, at the initiative of the International Union of Theoretical and Applied Mechanics (IUTAM) . The research topics discussed concerned the acoustics of unstable and turbulent flows and the noise generated by movable surfaces. Other subjects of interest were thermoacoustics, diffraction, and acoustic propagation through turbulence. Applications of numerical and experimental techniques to source diagnostics were discussed, as was active noise control. In Hydroacoustics the emphasis was on noise due to flow induced vibrations. There were 8 general invited lecturers and 43 other contributors, with 150 participants form 14 countries. Sufficient time was provided for discussions and social gatherings. For example, there was the opening of the high speed anechoic wind tunnel of the Centre Acoustique, and a welcome address given by the Mayor of Lyon in his historic City Hall. The organizing Committee of the Symposium wish to express their thanks to la Direction des Recherches Etudes et Techniques du Ministere des Armees (DRET), Ie Centre National de la Recherche Scientifique (CNRS), Ie Conseil General du Rhone, l'Association Universitaire de Mecanique (AUM), Ie Ministere de l'Environnement, for financial support. Le Groupement des Acousticiens de langue frangaise (GALF) helped advertise the meeting. The organizers are also indebted to the International Union of Theoretical and Applied Mechanics for providing travel subsidies to young scientists
Download or read book Combustion Waves and Fronts in Flows written by Paul Clavin and published by Cambridge University Press. This book was released on 2016-07-28 with total page 723 pages. Available in PDF, EPUB and Kindle. Book excerpt: A self-contained presentation of the dynamics of nonlinear waves in combustion and other non-equilibrium energetic systems for students and specialists.
Download or read book Turbulent Combustion written by Norbert Peters and published by Cambridge University Press. This book was released on 2000-08-15 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combustion of fossil fuels remains a key technology for the foreseeable future. It is therefore important that we understand the mechanisms of combustion and, in particular, the role of turbulence within this process. Combustion always takes place within a turbulent flow field for two reasons: turbulence increases the mixing process and enhances combustion, but at the same time combustion releases heat which generates flow instability through buoyancy, thus enhancing the transition to turbulence. The four chapters of this book present a thorough introduction to the field of turbulent combustion. After an overview of modeling approaches, the three remaining chapters consider the three distinct cases of premixed, non-premixed, and partially premixed combustion, respectively. This book will be of value to researchers and students of engineering and applied mathematics by demonstrating the current theories of turbulent combustion within a unified presentation of the field.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Generation and Radiation of Supersonic Jet Noise Theory of turbulence generated jet noise noise radiation from upstream sources and combustion noise written by and published by . This book was released on 1972 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1978 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Lewis Research Center Technical Publications Announced in 1977 written by Lewis Research Center and published by . This book was released on 1978 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This compilation of abstracts describes and indexes over 780 technical reports resulting from the scientific and engineering work performed and managed by the Lewis Research Center in 1977. All the publications were announced in the 1977 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Documents cited include research reports, journal articles, conference presentations, patents and patent applications, and theses.
Download or read book Nonsteady Flame Propagation written by George H. Markstein and published by Elsevier. This book was released on 2014-12-02 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonsteady Flame Propagation provides information pertinent to flame propagation in gaseous media. This book focuses on linearized treatments and the comparison of their results with experimental observations. Organized into nine chapters, this book begins with an overview of the challenge of nonlinear problems and examines the essentially nonlinear character of the flame phenomena, which has been artificially suppressed in analyses by the use of linearized perturbation treatments. This text then summarizes the development regarding rocket-shaped burners. Other chapters consider the advantages as well as the limitations of linearized analyses. This book discusses as well a general treatment of the discontinuous-flame-front model and summarizes the results of studies of burner that use secondary air. The final chapter deals with re-examining the possibilities of using pulsating combustion in propulsion or in other applications. This book is a valuable resource for chemical engineers, chemists, scientists, and research workers.
Download or read book Thermoacoustic Combustion Instability Control written by Dan Zhao and published by Academic Press. This book was released on 2023-02-13 with total page 1145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoacoustic Combustion Instability Control: Engineering Applications and Computer Codes provides a unique opportunity for researchers, students and engineers to access recent developments from technical, theoretical and engineering perspectives. The book is a compendium of the most recent advances in theoretical and computational modeling and the thermoacoustic instability phenomena associated with multi-dimensional computing methods and recent developments in signal-processing techniques. These include, but are not restricted to a real-time observer, proper orthogonal decomposition (POD), dynamic mode decomposition, Galerkin expansion, empirical mode decomposition, the Lattice Boltzmann method, and associated numerical and analytical approaches. The fundamental physics of thermoacoustic instability occurs in both macro- and micro-scale combustors. Practical methods for alleviating common problems are presented in the book with an analytical approach to arm readers with the tools they need to apply in their own industrial or research setting. Readers will benefit from practicing the worked examples and the training provided on computer coding for combustion technology to achieve useful results and simulations that advance their knowledge and research. - Focuses on applications of theoretical and numerical modes with computer codes relevant to combustion technology - Includes the most recent modeling and analytical developments motivated by empirical experimental observations in a highly visual way - Provides self-contained chapters that include a comprehensive, introductory section that ensures any readers new to this topic are equipped with required technical terms
Download or read book 40th AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2002 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report of the National Advisory Committee for Aeronautics written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1956 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes the Committee's Technical reports no. 1-1058, reprinted in v. 1-37.
