Download or read book Turbulent Swirling Jets with Excitation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-04 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: An existing cold-jet facility at NASA Lewis Research Center was modified to produce swirling flows with controllable initial tangential velocity distribution. Two extreme swirl profiles, i.e., one with solid-body rotation and the other predominated by a free-vortex distribution, were produced at identical swirl number of 0.48. Mean centerline velocity decay characteristics of the solid-body rotation jet flow exhibited classical decay features of a swirling jet with S - 0.48 reported in the literature. However, the predominantly free-vortex distribution case was on the verge of vortex breakdown, a phenomenon associated with the rotating flows of significantly higher swirl numbers, i.e., S sub crit greater than or equal to 0.06. This remarkable result leads to the conclusion that the integrated swirl effect, reflected in the swirl number, is inadequate in describing the mean swirling jet behavior in the near field. The relative size (i.e., diameter) of the vortex core emerging from the nozzle and the corresponding tangential velocity distribution are also controlling factors. Excitability of swirling jets is also investigated by exciting a flow with a swirl number of 0.35 by plane acoustic waves at a constant sound pressure level and at various frequencies. It is observed that the cold swirling jet is excitable by plane waves, and that the instability waves grow about 50 percent less in peak r.m.s. amplitude and saturate further upstream compared to corresponding waves in a jet without swirl having the same axial mass flux. The preferred Strouhal number based on the mass-averaged axial velocity and nozzle exit diameter for both swirling and nonswirling flows is 0.4. Taghavi, Rahmat and Farokhi, Saeed Unspecified Center NASA-CR-180895, NAS 1.26:180895 NCC3-56; RTOP 505-62-21...
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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Coherent Structures Dynamical Systems and Symmetry written by Philip Holmes and published by Cambridge University Press. This book was released on 2012-02-23 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes methods revealing the structures and dynamics of turbulence for engineering, physical science and mathematics researchers working in fluid dynamics.
Download or read book High Performance Computing in Science and Engineering 08 written by Wolfgang E. Nagel and published by Springer Science & Business Media. This book was released on 2009-01-10 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discussions and plans on all scienti?c, advisory, and political levels to realize an even larger “European Supercomputer” in Germany, where the hardware costs alone will be hundreds of millions Euro – much more than in the past – are getting closer to realization. As part of the strategy, the three national supercomputing centres HLRS (Stuttgart), NIC/JSC (Julic ̈ h) and LRZ (Munich) have formed the Gauss Centre for Supercomputing (GCS) as a new virtual organization enabled by an agreement between the Federal Ministry of Education and Research (BMBF) and the state ministries for research of Baden-Wurttem ̈ berg, Bayern, and Nordrhein-Westfalen. Already today, the GCS provides the most powerful high-performance computing - frastructure in Europe. Through GCS, HLRS participates in the European project PRACE (Partnership for Advances Computing in Europe) and - tends its reach to all European member countries. These activities aligns well with the activities of HLRS in the European HPC infrastructure project DEISA (Distributed European Infrastructure for Supercomputing Appli- tions) and in the European HPC support project HPC-Europa. Beyond that, HLRS and its partners in the GCS have agreed on a common strategy for the installation of the next generation of leading edge HPC hardware over the next ?ve years. The University of Stuttgart and the University of Karlsruhe have furth- more agreed to bundle their competences and resources.
Download or read book Advances in IC Engines and Combustion Technology written by Ashwani K. Gupta and published by Springer Nature. This book was released on 2020-08-18 with total page 939 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select peer-reviewed proceedings of the 26th National Conference on IC Engines and Combustion (NCICEC) 2019 which was organised by the Department of Mechanical Engineering, National Institute of Technology Kurukshetra under the aegis of The Combustion Institute-Indian Section (CIIS). The book covers latest research and developments in the areas of combustion and propulsion, exhaust emissions, gas turbines, hybrid vehicles, IC engines, and alternative fuels. The contents include theoretical and numerical tools applied to a wide range of combustion problems, and also discusses their applications. This book can be a good reference for engineers, educators and researchers working in the area of IC engines and combustion.
Download or read book NASA Conference Publication written by and published by . This book was released on 1990 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1991 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1991 with total page 1430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Flows written by Jean Piquet and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 767 pages. Available in PDF, EPUB and Kindle. Book excerpt: obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.
Download or read book Aeropropulsion 1987 written by and published by . This book was released on 1990 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preprints for the Symposium on Turbulence written by and published by . This book was released on 1992 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Issues in Aerospace and Defense Research and Application 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Aerospace and Defense Research and Application: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Aerospace and Defense Research and Application. The editors have built Issues in Aerospace and Defense Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Aerospace and Defense Research and Application in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Aerospace and Defense Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1966 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition Turbulence and Noise written by Reda R. Mankbadi and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence takes place in most flow situations whethertheyoccur naturally or in technological systems. Therefore, considerable effort is being expended in an attempt to understand the phenomenon of turbulence. The recent discovery ofcoherent structure in turbulent shear flows and the modem developments in computer capabilities have revolutionized research work in turbulence. There is a strong evidence that the coherent structure in turbulent shear flows is reminiscent of nonlinear stability waves. As such, the interest in nonlinear stability waves has increased not only for the understandingofthe latterstages of the laminar-turbulent transition process, but also for understanding the coherent structures in turbulent flows. Also. the advances in computers have made direct numerical simulation possible at Low-Reynolds numbers and large-eddy simulation possible at high Reynolds numbers. This made first-principles prediction of turbulence-generated noise feasible. Therefore, this book aims at presenting a graduate-level introductory study of turbulence while accounting for such recent views of concern to researchers. This book is an outgrowth oflecture notes on the subject offered to graduate students in engineering. The book should be of interest to research engineers and graduatestudents in science and engineering. The theoretical basis presented is sufficient not only for studying the specialized literature on turbulence but also for theoretical investigations on the subject.
Download or read book A Numerical Investigation of Skewed Mixing Layers written by Stanford University. Thermosciences Division. Thermosciences Division and published by . This book was released on 1995 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Turbulence XI written by J. M. L. M. Palma and published by Springer Science & Business Media. This book was released on 2008-01-08 with total page 825 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume comprises the communications presented at the ETC 11, the EUROMECH European Turbulence conference held in 2007 in Porto. The scientific committee has chosen the contributions out of the following topics: Acoustics of turbulent flows; Atmospheric turbulence; Control of turbulent flows; Geophysical and astrophysical turbulence; Instability and transition; Intermittency and scaling; Large eddy simulation and related techniques; MHD turbulence; Reacting and compressible turbulence; Transport and mixing; Turbulence in multiphase and non-Newtonian flows; Vortex dynamics and structure formation; Wall bounded flows.
