Download or read book Transition to Detonation in Fuel air Explosive Clouds written by and published by . This book was released on 1993 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction to this paper shows experimental evidence that transition to detonation phenomena, similar to those identified in fuel/oxygen mixtures, can also occur in fuel/air mixtures. Such phenomena include the deflagration to detonation transition (DDT), where the critical conditions for the onset of detonation are established by the combustion process itself without an external high-energy source. The paper briefly reviews general aspects of the events leading to explosions and then describes some of the new research developments which impact on the DDT problem. In particular, theoretical & experimental results on the nature, behaviour, and initiation of gaseous detonations are reviewed. Observations of transition to detonation in fuel/air mixtures are also summarized, and the influence of mixture composition, experimental configuration, and scale on flame acceleration & transition phenomena are discussed. Some proposed models for transition to detonation are also reviewed, and proposals are made for future research to obtain a better understanding of DDT phenomena.
Download or read book Requirements for Initiation and Sustained Propagation of Fuel Air Explosives written by R. Knystautas and published by . This book was released on 1983 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: CONTENTS: Requirements for Initiation and Sustained Propagation of Fuel-air Explosives; Measurements of Cell Size in Hydrocarbon-air Mixtures and Predictions of Critical Tube Diameter, Critical Initiation Energy, and Detonability Limits; Effect of Geometry on the Transmission of Detonation through an Orifice; Large-Scale Experiments on the Transmission of Fuel-air Detonations from Two-Dimensional Channels; Diffraction of Detonation from Tubes into a Large Fuel-air Explosive cloud; Dynamic Parameters of Gaseous Detonations; High-speed Turbulent Deflagrations and Transition to Detonation in H2-Air Mixtures. Keywords: Reprints.
Download or read book Major Research Topics in Combustion written by M.Y. Hussaini and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Institute for Computer Applications in Science and Engineer ing (ICASE) and NASA Langley Research Center (LaRC) brought together on October 2-4, 1989 experts in the various areas of com bustion with a view to expose them to some combustion problems of technological interest to LaRC and possibly foster interaction with the academic community in these research areas. The top ics chosen for this purpose were flame structure, flame stability, flame holding/extinction, chemical kinetics, turbulence-kinetics in teraction, transition to detonation, and reacting free shear layers. The lead paper set the stage by discussing the status and issues of supersonic combustion relevant to scramjet engine. Then the ex perts were called upon i) to review the current status of knowledge in the aforementioned ;:I. reas, ii) to focus on how this knowledge can be extended and applied to high-speed combustion, and iii) to suggest future directions of research in these areas. Each topic was then dealt with in a position paper followed by formal discussion papers and a general discussion involving the participants. The position papers discussed the state-of-the-art with an emphasis on key issues that needed to be resolved in the near future. The discussion papers crit ically examined these issues and filled in any lacunae therein. The edited versions of the general discussions in the form of questions from the audience and answers from the speakers are included wher ever possible to give the reader the flavor of the lively interactions that took place.
Download or read book A Study of the Growing Danger of Detonation in Unconfined Gas Cloud Explosions written by John A. Brown and published by . This book was released on 1973 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a real and growing danger of detonation of unconfined fuel-air clouds formed by massive industrial gas spills, and the danger increases with the size of the spill. A simple flame is probably not enough to initiate detonation of an unconfined gas cloud no matter how large the scale; but small contributory explosions such as a bursting pressure vessel or a muffler backfire can initiate detonations if strategically located, and gas clouds burning under confinement can undergo spontaneous transition to detonation and initiate open-air clouds. Large scale spills present a greater likelihood of detonation than do smaller spills simply because they entail more opportunities for confined burning to occur or for the cloud to reach an initiation source. Their burning phenomena do not appear to be intrinsically different from those of smaller spills. The most serious hitherto-unrecognized hazard in a refinery is the widespread existence of confined spaces in which a gas cloud can burn to detonation. They include spaces under floors and behind panels, the sewer system, stacks of empty pipe lengths and numerous others. Theoretically, a large spill of flammable gas could mix with the stoichiometric amount of air and possess the explosive power of a small atomic bomb; but experience has shown that the actual yield seldom exceeds 5% of the potential yield - although gas which does not participate in an explosion can still contribute to damage by participating in a subsequent firestorm. Techniques are available to make a quantitative assessment of the damage potential of a given spill in a given situation, and such an assessment would provide top management with the information needed to make an informed risk decision. Techniques are also available to reduce the risk of explosion in the event of a spill. They include limiting the scale of processing, limiting the growth of spill clouds by pilot lights, elimination of confined spaces in which a flame can grow to detonation, greater use of flame arrestors and the installation of gas quench systems. This report is a scouting and planning study intended to give an appreciation for the kind and amount of information that exists and to assess what might be accomplished by a full-scale safety R & D program. It presents a recommended program in sufficient detail for management evaluation and action; with the data and evidential basis for the recommendation.
Download or read book Dynamics of Detonations and Explosions written by and published by AIAA. This book was released on 1991 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flame Acceleration and Transition to Detonation in Large Fuel air Clouds with Obstacles U written by I. O. Moen and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamental Mechanisms of Unconfined Detonation of Fuel Air Explosions written by and published by . This book was released on 1980 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research during the past year has led to some significant results which have profound implications in the area of vapor cloud explosion in general, and in the area of 'shockless' initiation of detonation in particular. In brief we have; (1) demonstrated experimentally that initiation of detonation can be achieved by injecting a chemical catalyst into a fuel-air mixture, (ii) demonstrated experimentally that direct initiation can be achieved by seeding an explosive mixture with free radicals of the appropriate concentration and spatial distribution, (iii) demonstrated experimentally that direct initiation can be achieved via turbulent mixing between an explosive mixture and its combustion products, (iv) demonstrated experimentally that unconfined turbulent flame speeds exceeding 400 m/s can readily be achieved in a mixture as inert as methane air, (v) clarified through experiments the role of confinement on the propagation of detonations near the detonability limits, and (vi) assessed the far field destructive potential of FAE weapons by calculating numerically the effective blast energy of non-ideal blast waves generated by vapor cloud explosions. (Author).
Download or read book Guidelines for Vapor Cloud Explosion Pressure Vessel Burst BLEVE and Flash Fire Hazards written by CCPS (Center for Chemical Process Safety) and published by John Wiley & Sons. This book was released on 2011-12-01 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide provides an overview of methods for estimating the characteristics of vapor cloud explosions, flash fires, and boiling-liquid-expanding-vapor explosions (BLEVEs) for practicing engineers. It has been updated to include advanced modeling technology, especially with respect to vapor cloud modeling and the use of computational fluid dynamics. The text also reviews past experimental and theoretical research and methods to estimate consequences. Heavily illustrated with photos, charts, tables, and diagrams, this manual is an essential tool for safety, insurance, regulatory, and engineering students and professionals.
Download or read book Guidelines for Evaluating the Characteristics of Vapor Cloud Explosions Flash Fires and BLEVEs written by CCPS (Center for Chemical Process Safety) and published by John Wiley & Sons. This book was released on 2010-09-14 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: The serious consequences of vapor cloud explosions, flash fires, and BLEVEs are very well known. Better understanding of the characteristics of these phenomena and models to calculate their consequences are key to effective prevention and mitigation. Cited by EPA in its 1996 document, "Off-site Consequence Analysis Guidance, " the first half of the book describes the characteristics of these phenomena and gives an overview of past experimental and theoretical research and methods to estimate consequences. The second part focuses on methods for consequence estimating by presenting sample problems. The entire book is heavily illustrated with photos, charts, tables, and diagrams, and each chapter has a full set of references for additional reading.
Download or read book INITIATION OF DETONATION IN UNCONFINED NATURAL GAS AIR CLOUDS written by J.A. NICHOLLS and published by . This book was released on 1980 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Wave Science and Technology Reference Library Vol 4 written by F. Zhang and published by Springer Science & Business Media. This book was released on 2009-06-12 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth of several volumes on solids in this series, the six extensive chapters here are more specifically concerned with detonation and shock compression waves in reactive heterogeneous media, including mixtures of solid, liquid and gas phases.
Download or read book Cloud Development and Blast Wave Measurements from Detonation Fuel Air Explosive Charges written by Hakan Axelsson and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Explosions written by J. Raymond Bowen and published by . This book was released on 1986 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Explosions (Volume 106) primarily concerns the interrelationship between the rate processes of energy deposition in a compressible medium and the concurrent nonsteady flow as it typically occurs in explosion phenomena. Dynamics of reactive Systems (Volume 105--AD-A173 108) spans a broader area, encompassing the processes coupling the dynamics of fluid flow and molecular transformations in reactive media, and occurring in any combustion system. Major topics in this volume include: Flame acceleration and transition to detonation; Initiation and transmission of detonations; Detonation structure and limit propagation; Detonation kinetics, structure, and boundary effects; Explosions, shock reflections, and blast waves; Heterogeneous detonations and explosions; and Condensed phase shocks and detonations.
Download or read book Experimental and Theoretical Modeling of Fuel Air Detonations The Distributed Blast Concept written by and published by . This book was released on 1973 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present an analysis of results obtained in developing experimental techniques, defining critical explosive parameters and evolving a theoretical model for heterogeneous detonation. The dispersions may be of the fuel-air type, or of the monopropellant type, where no external oxygen is required. Alternatively, the explosive may exist as a film on a surface. Most studies have centered on the detonation of clouds of liquid fuel drops in air. Experimental and theoretical studies have been performed to determine the interrelationships between chemical and physical factors in the ignition of liquid fuel drops by shock waves. A theoretical model has been developed to describe the complex process by which large liquid drops are fragmented. Theoretical comparisons are presented of the pressure and impulses generated by fuel-air clouds of different geometries and those from high explosives of equivalent weight and energy. In addition other types of heterogeneous detonation are considered. They include the use of solid fuel and film detonations.
Download or read book Combustion Processes in Propulsion written by Gabriel Roy and published by Butterworth-Heinemann. This book was released on 2006 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical propulsion comprises the science and technology of using chemical reactions of any kind to create thrust and thereby propel a vehicle or object to a desired acceleration and speed. Cumbustion Processes in Propulsion focuses on recent advances in the design of very highly efficient, low-pollution-emitting propulsion systems, as well as advances in testing, diagnostics and analysis. It offers unique coverage of Pulse Detonation Engines, which add tremendous power to jet thrust by combining high pressure with ignition of the air/fuel mixture. Readers will learn about the advances in the reduction of jet noise and toxic fuel emissions-something that is being heavily regulated by relevant government agencies. Lead editor is one of the world's foremost combustion researchers, with contributions from some of the world's leading researchers in combustion engineering Covers all major areas of chemical propulsion-from combustion measurement, analysis and simulation, to advanced control of combustion processes, to noise and emission control Includes important information on advanced technologies for reducing jet engine noise and hazardous fuel combustion emissions
Download or read book Combustion Flames and Explosions of Gases written by Bernard Lewis and published by Academic Press. This book was released on 2013-10-22 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion, Flames, and Explosions of Gases, Second Edition focuses on the processes, methodologies, and reactions involved in combustion phenomena. The publication first offers information on theoretical foundations, reaction between hydrogen and oxygen, and reaction between carbon monoxide and oxygen. Discussions focus on the fundamentals of reaction kinetics, elementary and complex reactions in gases, thermal reaction, and combined hydrogen-carbon monoxide-oxygen reaction. The text then elaborates on the reaction between hydrocarbons and oxygen and combustion waves in laminar flow. The manuscript tackles combustion waves in turbulent flow and air entrainment and burning of jets of fuel gases. Topics include effect of turbulence spectrum and turbulent wrinkling on combustion wave propagation; ignition of high-velocity streams by hot solid bodies; burners with primary air entrainment; and description of jet flames. The book then takes a look at detonation waves in gases; emission spectra, ionization, and electric-field effects in flames; and methods of flame photography and pressure recording. The publication is a valuable reference for readers interested in combustion phenomena.
