Download or read book The Fractal Geometry of Round Turbulent Cryogenic Nitrogen Jets at Supercritical Pressures written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Box-counting and EDM methods were used to measure the fractal dimension of round turbulent cryogenic nitrogen jets at pressures ranging from subcritical to supercritical pressures. Both method produced similar trends, with close quantitative agreement for a suitably small box-counting scale. At subcritical pressures, the fractal dimension was found to be consistent with the fractal dimension of a spray in the 2nd wind-induced atomization regime. The fractal dimension tended to increase as pressure increased, until at supercritical pressures the fractal dimension was found to be consistent with that of gas jets and mixing layers. The results constitute additional quantitative evidence for the hypothesis that subcritical jets exhibit mainly spray-like behavior, while supercritical jets exhibit mainly gas-like behavior. This appears to have been the first time pressure effects on the fractal dimension of turbulent jets has been measured.
Download or read book Fractal Geometry and Growth Rate Changes of Cryogenic Jets Near the Critical Point written by and published by . This book was released on 1999 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Injection of several pure fluids into a chamber with different ambient gases under supercritical temperature but sub- to supercritical condition based on the injectant thermodynamic critical conditions resulted in the following: the jet exhibits classical liquid-like jet second wind-induced type breakup until chamber pressure reaches near the critical point of the jet substance beyond which gas-like visual behavior is observed and no drops are found. For the first time, these visual qualitative observations are verified quantitatively by agreement between the experimental growth rate of the jets reported here and those developed theoretically by D. Brown, D. Papamoschou and A. and Roshko, and P.E. Dimotakis for the incompressible variable-density mixing layers. This gas-like jet appearance is also confirmed quantitatively and for the first time by fractal analysis of the outer contour of the jet. The geometry of the jet interface shows a transition from Euclidean to a fractal interface with a fractal dimension near the values measured and reported by others for gaseous turbulent jets. Finally, based on a physical hypothesis implying that at the point where gas-like behavior appears, the value of the jet interface bulge separation/formation characteristic time should be near that of gasification, an "intuitive/smart" equation is proposed for the growth rate that agrees well with the presented experimental data for a wide range of density ratios. (9 figures, 40 refs.).
Download or read book Visual Characteristics and Initial Growth Rates of Round Cryogenic Jets at Subcritical and Supercritical Pressures written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The visual characteristics and initial growth rates of round cryogenic jets injected into subcritical and supercritical pressures were studied. We found that the jet exhibits liquid-like and gas-like characteristics at subcritical and supercritical pressures, respectively. Explanations are offered. The jet spreading angle at supercritical pressures has been demonstrated to agree quantitatively with the theoretical spreading angle of incompressible but variable density turbulent gas jets, the first time more than a qualitative visual similarity with gas jets has ever been demonstrated. In addition, the present measurements of spreading rates have been plotted along with other measurements for subsonic incompressible constant density and variable density jets, liquid sprays, supersonic jets, and other mixing layers in a plot spanning four orders of magnitude in gas-to-liquid density ratio. This is the first time these results have been consolidated in a single plot over such a large range of density ratio.
Download or read book IUTAM Symposium on Turbulent Mixing and Combustion written by Andrew Pollard and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goals of the Symposium were to draw together researchers in turbulence and combustion so as to highlight advances and challenge the boundaries to our understanding of turbulent mixing and combus tion from both experimental and simulation perspectives; to facilitate cross-fertilization between leaders in these two fields. These goals were noted to be important given that turbulence itself is viewed as the last great problem in classical physics and the addition of chemical reaction amplifies the difficulties enormously. The papers that have been included here reflect the richness of our subject. Turbulence is rich and complex in its own right. And, its inner structure, hidden in the morass of scales, large and small, can dominate transport. Earlier IUTAM Symposia have considered this field, Eddy Structure Identification in Free Turbulent Flows, Bonnet and Glauser (eds) 1992 and Simulation and Identification of Organized Structures in Flows, Sorensen, Hopfinger and Aubry (eds) 1997. The combustion community is well served by its specialized events, most notable is the bi annual International Combustion Symposium, held under the auspices of the Combustion Institute. Mixing is often considered somewhere in between these two. This broad landscape was addressed in this Sym posium in a somewhat temporal linear fashion of increasing complexity. The lectures considered the many challenges posed by adding one ele ment to the base formed by others: turbulence and turbulent mixing in the absence of combustion through to turbulent mixing dominated by chemistry and combustion.
Download or read book Behavior of a Round Cryogenic Jet at Below and Above the Critical Pressure written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an effort to investigate and understand the behavior of the injected cryogenic fluid and its environment, a high pressure chamber is used into which pure N2 He, and O2 fluids are injected. Several chamber media are selected including, N2, Me, and mixtures of CO+N2. The effects of chamber pressure ranging from a subcritical to a supercritical values at a supercritical chamber are photographically observed and documented near the injector hole exit region using a CCD camera illuminated by a short-duration back-lit strobe light. At low subcritical chamber pressures, the jets exhibit small surface irregularities that amplify downstream, looking intact, shiny, but wavy on the surface which eventually break up into irregularly-shaped small entities. Further increase of chamber pressure aids formation of many small droplets on the surface of the jet ejecting away only within a narrow region below the critical pressure of the injected fluid similar to a second wind-induced jet breakup - regime. Raising the chamber pressure, transition into a full atomization regime is inhibited by reaching near, but S slightly lower than, the critical pressure of the injectant where both surface tension and heat of vaporization are sufficiently reduced. The jet appearance changes abruptly at this point and remains the same to resemble a turbulent gas jet injection. The jet initial growth rate, is extracted from a large set of images and plotted with the available data on liquid fuel injection in diesel engine environment, turbulent incompressible, and variable density jets and mixing layers, creating a unique plot on its own. The jet spreading rate measurements agree well with a theoretical equation proposed for incompressible but variable density turbulent mixing layers by Papamoschou and Roshko 1 and follow the trend of that of Dimotakis.
Download or read book Commentarii Collegii Conimbricensis soc Jesu In libros de generatione et coruptione Aristotelis written by and published by . This book was released on 1650 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scale Invariance written by Annick LESNE and published by Springer Science & Business Media. This book was released on 2011-11-04 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: During a century, from the Van der Waals mean field description (1874) of gases to the introduction of renormalization group (RG techniques 1970), thermodynamics and statistical physics were just unable to account for the incredible universality which was observed in numerous critical phenomena. The great success of RG techniques is not only to solve perfectly this challenge of critical behaviour in thermal transitions but to introduce extremely useful tools in a wide field of daily situations where a system exhibits scale invariance. The introduction of scaling, scale invariance and universality concepts has been a significant turn in modern physics and more generally in natural sciences. Since then, a new "physics of scaling laws and critical exponents", rooted in scaling approaches, allows quantitative descriptions of numerous phenomena, ranging from phase transitions to earthquakes, polymer conformations, heartbeat rhythm, diffusion, interface growth and roughening, DNA sequence, dynamical systems, chaos and turbulence. The chapters are jointly written by an experimentalist and a theorist. This book aims at a pedagogical overview, offering to the students and researchers a thorough conceptual background and a simple account of a wide range of applications. It presents a complete tour of both the formal advances and experimental results associated with the notion of scaling, in physics, chemistry and biology.
Download or read book Handbook of Atomization and Sprays written by Nasser Ashgriz and published by Springer Science & Business Media. This book was released on 2011-02-18 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomization and sprays are used in a wide range of industries: mechanical, chemical, aerospace, and civil engineering; material science and metallurgy; food; pharmaceutical, forestry, environmental protection; medicine; agriculture; meteorology and others. Some specific applications are spray combustion in furnaces, gas turbines and rockets, spray drying and cooling, air conditioning, powdered metallurgy, spray painting and coating, inhalation therapy, and many others. The Handbook of Atomization and Sprays will bring together the fundamental and applied material from all fields into one comprehensive source. Subject areas included in the reference are droplets, theoretical models and numerical simulations, phase Doppler particle analysis, applications, devices and more.
Download or read book Vertical Turbulent Buoyant Jets written by Ching Jen Chen and published by Pergamon. This book was released on 1980 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiphase Flow Handbook Second Edition written by Efstathios Michaelides and published by CRC Press. This book was released on 2016-10-26 with total page 1559 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Multiphase Flow Handbook, Second Edition is a thoroughly updated and reorganized revision of the late Clayton Crowe’s work, and provides a detailed look at the basic concepts and the wide range of applications in this important area of thermal/fluids engineering. Revised by the new editors, Efstathios E. (Stathis) Michaelides and John D. Schwarzkopf, the new Second Edition begins with two chapters covering fundamental concepts and methods that pertain to all the types and applications of multiphase flow. The remaining chapters cover the applications and engineering systems that are relevant to all the types of multiphase flow and heat transfer. The twenty-one chapters and several sections of the book include the basic science as well as the contemporary engineering and technological applications of multiphase flow in a comprehensive way that is easy to follow and be understood. The editors created a common set of nomenclature that is used throughout the book, allowing readers to easily compare fundamental theory with currently developing concepts and applications. With contributed chapters from sixty-two leading experts around the world, the Multiphase Flow Handbook, Second Edition is an essential reference for all researchers, academics and engineers working with complex thermal and fluid systems.
Download or read book Direct Numerical Simulations of Gas Liquid Multiphase Flows written by Grétar Tryggvason and published by Cambridge University Press. This book was released on 2011-03-10 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurately predicting the behaviour of multiphase flows is a problem of immense industrial and scientific interest. Modern computers can now study the dynamics in great detail and these simulations yield unprecedented insight. This book provides a comprehensive introduction to direct numerical simulations of multiphase flows for researchers and graduate students. After a brief overview of the context and history the authors review the governing equations. A particular emphasis is placed on the 'one-fluid' formulation where a single set of equations is used to describe the entire flow field and interface terms are included as singularity distributions. Several applications are discussed, showing how direct numerical simulations have helped researchers advance both our understanding and our ability to make predictions. The final chapter gives an overview of recent studies of flows with relatively complex physics, such as mass transfer and chemical reactions, solidification and boiling, and includes extensive references to current work.
Download or read book On the Continuity of the Gaseous and Liquid States written by J. D. Van Der Waals and published by Courier Corporation. This book was released on 2004-01-01 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This much-cited thesis by J. D. van der Waals, the recipient of the 1910 Nobel Prize in physics, is accompanied by an introductory essay by J. S. Rowlinson and another work by van der Waals on the theory of liquid mixtures. 1988 edition.
Download or read book Turbulent Jets written by N. Rajaratnam and published by Elsevier. This book was released on 1976-01-01 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent Jets
Download or read book Advances in Turbulence VII written by Uriel Frisch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Turbulence VII contains an overview of the state of turbulence research with some bias towards work done in Europe. It represents an almost complete collection of the invited and contributed papers delivered at the Seventh European Turbulence Conference, sponsored by EUROMECH and ERCOFTAC and organized by the Observatoire de la Côte d'Azur. New high-Reynolds number experiments combined with new techniques of imaging, non-intrusive probing, processing and simulation provide high-quality data which put significant constraints on possible theories. For the first time, it has been shown, for a class of passive scalar problems, why dimensional analysis sometimes gives the wrong answers and how anomalous intermittency corrections can be calculated from first principles. The volume is thus geared towards specialists in the area of flow turbulence who could not attend the conference as well as anybody interested in this rapidly moving field.
Download or read book Mathematics of Fractals written by Masaya Yamaguchi and published by American Mathematical Soc.. This book was released on 1997 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims at providing a handy explanation of the notions behind the self-similar sets called "fractals" and "chaotic dynamical systems". The authors emphasize the beautiful relationship between fractal functions (such as Weierstrass's) and chaotic dynamical systems; these nowhere-differentiable functions are generating functions of chaotic dynamical systems. These functions are shown to be in a sense unique solutions of certain boundary problems. The last chapter of the book treats harmonic functions on fractal sets.
Download or read book Internal Combustion Engines and Powertrain Systems for Future Transport 2019 written by IMECHE and published by CRC Press. This book was released on 2020-03-09 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the changing landscape of the transport sector, there are also alternative powertrain systems on offer that can run independently of or in conjunction with the internal combustion (IC) engine. This shift has actually helped the industry gain traction with the IC Engine market projected to grow at 4.67% CAGR during the forecast period 2019-2025. It continues to meet both requirements and challenges through continual technology advancement and innovation from the latest research. With this in mind, the contributions in Internal Combustion Engines and Powertrain Systems for Future Transport 2019 not only cover the particular issues for the IC engine market but also reflect the impact of alternative powertrains on the propulsion industry. The main topics include: • Engines for hybrid powertrains and electrification • IC engines • Fuel cells • E-machines • Air-path and other technologies achieving performance and fuel economy benefits • Advances and improvements in combustion and ignition systems • Emissions regulation and their control by engine and after-treatment • Developments in real-world driving cycles • Advanced boosting systems • Connected powertrains (AI) • Electrification opportunities • Energy conversion and recovery systems • Modified or novel engine cycles • IC engines for heavy duty and off highway Internal Combustion Engines and Powertrain Systems for Future Transport 2019 provides a forum for IC engine, fuels and powertrain experts, and looks closely at developments in powertrain technology required to meet the demands of the low carbon economy and global competition in all sectors of the transportation, off-highway and stationary power industries.
