Download or read book Structure of a Turbulent Reacting Mixing Layer written by Richard S. Miller and published by . This book was released on 1993 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Mixing in Nonreactive and Reactive Flows written by S. Murthy and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence, mixing and the mutual interaction of turbulence and chemistry continue to remain perplexing and impregnable in the fron tiers of fluid mechanics. The past ten years have brought enormous advances in computers and computational techniques on the one hand and in measurements and data processing on the other. The impact of such capabilities has led to a revolution both in the understanding of the structure of turbulence as well as in the predictive methods for application in technology. The early ideas on turbulence being an array of complicated phenomena and having some form of reasonably strong coherent struc ture have become well substantiated in recent experimental work. We are still at the very beginning of understanding all of the aspects of such coherence and of the possibilities of incorporating such structure into the analytical models for even those cases where the thin shear layer approximation may be valid. Nevertheless a distinguished body of "eddy chasers" has come into existence. The structure of mixing layers which has been studied for some years in terms of correlations and spectral analysis is also getting better understood. Both probability concepts such as intermittency and conditional sampling as well as the concept of large scale structure and the associated strain seem to indicate possibilities of distinguishing and synthesizing 'engulfment' and molecular mixing.
Download or read book Visualizations of the Structure of the Turbulent Mixing Layer Under Compressible Conditions written by N. T. Clemens and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure of the Turbulent Mixing Layer written by Garry L. Brown and published by . This book was released on 1972 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of an experimental study of turbulent mixing between two streams of different density are summarized. The effects of density difference in flows at low Mach number are compared to those due to compressibility effects at high Mach number. The mixing layer at low Mach number is examined for large vortex structures. (Author).
Download or read book Direct Simulations of Chemically Reacting Turbulent Mixing Layers written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-11-03 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of direct numerical simulations of chemically reacting turbulent mixing layers are presented. This is an extension of earlier work to a more detailed study of previous three dimensional simulations of cold reacting flows plus the development, validation, and use of codes to simulate chemically reacting shear layers with heat release. Additional analysis of earlier simulations showed good agreement with self similarity theory and laboratory data. Simulations with a two dimensional code including the effects of heat release showed that the rate of chemical product formation, the thickness of the mixing layer, and the amount of mass entrained into the layer all decrease with increasing rates of heat release. Subsequent three dimensional simulations showed similar behavior, in agreement with laboratory observations. Baroclinic torques and thermal expansion in the mixing layer were found to produce changes in the flame vortex structure that act to diffuse the pairing vortices, resulting in a net reduction in vorticity. Previously unexplained anomalies observed in the mean velocity profiles of reacting jets and mixing layers were shown to result from vorticity generation by baroclinic torques. Metcalfe, Ralph W. and Mcmurtry, Patrick A. and Jou, Wen-Huei and Riley, James J. and Givi, Peyman Unspecified Center...
Download or read book Direct Simulations of Chemically Reacting Turbulent Mixing Layers written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of direct numerical simulations of chemically reacting turbulent mixing layers are presented. This is an extension of earlier work to a more detailed study of previous three dimensional simulations of cold reacting flows plus the development, validation, and use of codes to simulate chemically reacting shear layers with heat release. Additional analysis of earlier simulations showed good agreement with self similarity theory and laboratory data. Simulations with a two dimensional code including the effects of heat release showed that the rate of chemical product formation, the thickness of the mixing layer, and the amount of mass entrained into the layer all decrease with increasing rates of heat release. Subsequent three dimensional simulations showed similar behavior, in agreement with laboratory observations. Baroclinic torques and thermal expansion in the mixing layer were found to produce changes in the flame vortex structure that act to diffuse the pairing vortices, resulting in a net reduction in vorticity. Previously unexplained anomalies observed in the mean velocity profiles of reacting jets and mixing layers were shown to result from vorticity generation by baroclinic torques. Metcalfe, Ralph W. and Mcmurtry, Patrick A. and Jou, Wen-Huei and Riley, James J. and Givi, Peyman Unspecified Center...
Download or read book Turbulence in Mixing Operations written by Robert Brodkey and published by Elsevier. This book was released on 2012-12-02 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence in Mixing Operations: Theory and Application to Mixing and Reaction presents a summary of the current status of research on turbulent motion, mixing, and kinetics. Each chapter of this book discusses turbulence in the context of mixing and reaction in scalar fields. Chapters I and III discuss the classification of turbulent reacting systems and the different possibilities in this context. Chapter II reviews the properties of passive mixing. Chapter IV looks at turbulent mixing in chemically reactive flows. Chapter V uses different techniques to make parallel numerical calculations of both mixing and reaction. Finally, Chapter VI reviews turbulence and actual industrial mixing operations. This book will be of great value for chemical and industrial engineers, especially for those interested in turbulent and industrial mixing.
Download or read book Turbulent Mixing and Chemical Reactions written by Jerzy Bałdyga and published by John Wiley & Sons. This book was released on 1999-03-12 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent Mixing and Chemical Reactions Jerzy Ba???dyga, Warsaw University of Technology, Poland John R. Bourne, Visiting Professor, University of Birmingham, UK and Emeritus Professor, ETH Zurich, Switzerland The way in which reagents are mixed can greatly influence the yield and range of products formed by fast, multiple chemical reactions. Understanding this phenomenon enables chemists to carry out reactions more selectively, make better use of raw materials and simplify product workup and separation. Turbulent Mixing and Chemical Reactions presents a balanced treatment of the connection between mixing and reaction. It contains theoretical aspects, experimental methods and expected results as well as worked examples to illustrate problem solving. This book will be of interest to all scientists involved in chemical engineering, physical chemistry, and synthetic chemists in the fine chemical and pharmaceuticals industry.
Download or read book Effects of Turbulent Mixing on Chemical Reaction in an Aerosol producing Co flow Jet written by Thomas Paris Jenkins and published by . This book was released on 1997 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigates the effects of mixing on chemical reaction in a turbulent co-flow jet. After a jet is produced by a mixture of HCl (hydrogen chloride), air, and N2 (nitrogen) issuing from a pipe into a co-flowing stream of NH3 (gaseous ammonia) and air, a chemical reaction in which NH4Cl (ammonium chloride) aerosol with negligible heat release is produced. The product concentration field as marked by the aerosol is then characterized through the collection of data from which probability density functions can be constructed.
Download or read book High Resolution Measurements of Mixing and Reaction Processes in Turbulent Flows written by and published by . This book was released on 1992 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution multi-dimensional imaging measurements were reported of the detailed structure of mixing and combustion processes in turbulent flows. These measurements are unique because they provide the first fully-resolved quantitative data on scalar dissipation rate field structure in turbulent reacting flows. These molecular mixing rate data were coupled with a two- parameter non-equilibrium reaction chemistry formulation to generate instantaneous maps of combustion species concentration and reaction rate fields in turbulent flames under varying degrees of chemical non-equilibrium. Results showed that the reaction zone structure transitioned smoothly from a thin layer- like structure to broad distributed reaction zones as the flame extinction limit was approached. Additionally, fully-resolved four-dimensional spatio-temporal imaging measurements were used to measure the larger scale topology of these scalar dissipation layers. Results showed that the distribution of layer separations is very nearly lognormal. This finding verified a recent analytical model of the multiplicative character of the repeated stretching and folding processes leading to this layer-like structure in the scalar dissipation fields in turbulent flows. This model, coupled with this two-parameter non-equilibrium reaction chemistry formulation, provides a simple approach for predicting the fine structure of molecular mixing and non-equilibrium reaction chemistry in turbulent combustion.
Download or read book Chemical Reactions in Turbulent Mixing written by H. W. Liepmann and published by . This book was released on 1979 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combustion facility (H2-F2) is now nearing completion. As of this writing, a high speed mixing layer has been realized in the test section, using high pressure air. This certifies the flow facility down to and including the test section. Preliminary results on the effect of high heat release in a turbulent mixing zone were obtained in the NO-O3 experiment. These results are consistent with predictions based on previously measured p.d.f, 's in non-reacting mixing layers, but in conspicuous disagreements with a variety of accepted model calculations. These results demonstrate again the important influence of the large scale coherent structures on chemical reactions in turbulent flows. The Laser Induced Fluorescence technique has now been extended to allow direct space and time resolved measurements of the reaction products. The first four channels of the multi-channel laser Doppler velocimetry system are essentially completed. The first experiments using this new development are expected in the course of this summer. Digital image analysis of particle streak photography has also been explored as a direct means of two-dimensional measurements of the velocity field in a plane. Finally, a prototype system using a 100 element acoustic detector array has been completed. Initial measurements with four of these channels using 300 kHz sound have been successfully made. (Author).
Download or read book Turbulent Reactive Flows written by R. Borghi and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 958 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent reactive flows are of common occurrance in combustion engineering, chemical reactor technology and various types of engines producing power and thrust utilizing chemical and nuclear fuels. Pollutant formation and dispersion in the atmospheric environment and in rivers, lakes and ocean also involve interactions between turbulence, chemical reactivity and heat and mass transfer processes. Considerable advances have occurred over the past twenty years in the understanding, analysis, measurement, prediction and control of turbulent reactive flows. Two main contributors to such advances are improvements in instrumentation and spectacular growth in computation: hardware, sciences and skills and data processing software, each leading to developments in others. Turbulence presents several features that are situation-specific. Both for that reason and a number of others, it is yet difficult to visualize a so-called solution of the turbulence problem or even a generalized approach to the problem. It appears that recognition of patterns and structures in turbulent flow and their study based on considerations of stability, interactions, chaos and fractal character may be opening up an avenue of research that may be leading to a generalized approach to classification and analysis and, possibly, prediction of specific processes in the flowfield. Predictions for engineering use, on the other hand, can be foreseen for sometime to come to depend upon modeling of selected features of turbulence at various levels of sophistication dictated by perceived need and available capability.
Download or read book The Structure of the Turbulent Mixing Layer written by F. K. Browand and published by . This book was released on 1986 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent experimental results describing the vortical structure of the mixing layer are reviewed. The largest turbulent features are quasi two-dimensional vortices aligned along the span of the flow. As a result of interactions, the vortices rapidly develop an invariant space-time geometry. Superimposed on this vortex structure are smaller scales which include longitudinal vortices of size comparable to the Taylor microscale, and smaller scales which considerably enhance molecular mixing. These smaller scales coexist with the quasi two dimensional structure. At present, no theoretical framework is available to describe the geometrical features of these complex shear flows. (Reprints).
Download or read book Coherent Structures in Turbulent Shear Layers and Relation to Mixing Reaction and Combustion written by CALIFORNIA UNIV BERKELEY COLL OF ENGINEERING. and published by . This book was released on 1986 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of numerical analyses served as experiments which led to a broad range of ideas about the dynamics of mixing layer. One theme which emerged early was the adversary role of vorticity and of deformation - two quanities which attempt to subjugate each other and whose competition is the subject matter of the development and growth to the shear flow. Another strand of the work follows a number of instabilities (two and three dimensional) which lead to recognizable non-linear motions. A third focus of the work relates vorticity and the mixing of scalars. The work started out to attempt to explain striking experimental results and ended by making a number of predictions which have not yet been experimentally established. A significant fraction, though not all of the typical motions which are dynamically plausible in a shear layer have been examined and given simple analytic representation. Finally the basis for the effective control of the shear layer has been laid.
Download or read book The Design of a High Pressure High Temperature Turbulent Mixing Layer Apparatus written by Darius Mehri and published by . This book was released on 1996 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Simulation of Turbulent Mixing and Reaction written by Daniel Livescu and published by Springer Nature. This book was released on 2020-02-19 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights recent research advances in the area of turbulent flows from both industry and academia for applications in the area of Aerospace and Mechanical engineering. Contributions include modeling, simulations and experiments meant for researchers, professionals and students in the area.
Download or read book Turbulent Mixing layer written by Ben Ochora Latigo and published by . This book was released on 1979 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
