[PDF] Fundamental Mechanisms Of Unconfined Detonation Of Fuel Air Explosions eBook

Author :
Publisher :
Page : 101 pages
File Size : 41,66 MB
Release : 1980
Category :
ISBN :

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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).

Author : M.A. Nettleton
Publisher : Springer Science & Business Media
Page : 266 pages
File Size : 50,90 MB
Release : 2012-12-06
Category : Medical
ISBN : 9400931492

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My introduction to the fascinating phenomena associated with detonation waves came through appointments as an external fellow at the Department of Physics, University College of Wales, and at the Department of Mechanical Engineering, University of Leeds. Very special thanks for his accurate guidance through the large body of information on gaseous detonations are due to Professor D. H. Edwards of University College of Wales. Indeed, the onerous task of concisely enumerating the key features of unidimensional theories of detonations was undertaken by him, and Chapter 2 is based on his initial draft. When the text strays to the use of we, it is a deserved acknow ledgement of his contribution. Again, I should like to thank Professor D. Bradley of Leeds University for his enthusiastic encouragement of my efforts at developing a model of the composition limits of detonability through a relationship between run-up distance and composition of the mixture. The text has been prepared in the context of these fellowships, and I am grateful to the Central Electricity Generating Board for its permission to accept these appointments.

Author : M.Y. Hussaini
Publisher : Springer Science & Business Media
Page : 668 pages
File Size : 32,69 MB
Release : 2012-12-06
Category : Science
ISBN : 1461228840

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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.

Author : John A. Brown
Publisher :
Page : 110 pages
File Size : 39,45 MB
Release : 1973
Category : Shock waves
ISBN :

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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.