Author: Simon David Wilkinson
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: D. A. Jones
Publisher:
ISBN:
Category : Blast effect
Languages : en
Pages : 33

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Author: Juan A. Saenz
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We investigate the ignition and dynamics of detonation waves in condensed phase explosives using direct numerical simulations and asymptotic analysis. We develop a model to simulate deflagration to detonation transition in pentaerythritol tetranitrate powders. The model uses a continuum mechanics formulation of conservation laws for a mixture of solid reactants and gas products, written in terms of mixture quantities, plus two independent variables used to account for exothermic conversion of solid reactants into gas products, and compaction associated with pore collapse and grain rearrangement. We propose a simple empirical dependence of the reaction rate on the initial bed compaction that allows us to calibrate the model for a wide range of initial conditions. For the solid reactants we use a wide ranging equation of state. We suggest phenomenological closure relations, consistent with the limit of a compressible inert material and of a solid fully reactive material, such that the equation of state can be posed only in terms of mixture quantities and the reaction and compaction variables. We demonstrate the model's ability to capture deflagration to detonation transition in pentaerythritol tetranitrate powders by matching transients typically observed in experiments, through simulation. We develop an asymptotic formulation to calculate an intrinsic relation between the shock acceleration, velocity and curvature of self-sustained detonation waves in the limit of small time variation and small curvature of the lead shock front in condensed phase explosives. The formulation is developed in terms of a general, incomplete equation of state with composition variables to represent scalar quantities for a general range of phenomena. The results presented here are the first calculations obtained from asymptotic detonation shock dynamics relations for general material models. The formulation is a generalization of an asymptotic theory for a polytropic equation of state and a single step Arrhenius reaction rate model. We discuss the assumptions and justify the generalizations made that allow the use of general form incomplete equations of state. We test the proposed theory by calculating quasi-steady relations between detonation velocity and curvature and the dynamics of ignition events in a reactive hydrogen-oxygen mixture using an ideal equation of state and single step Arrhenius reaction rate model, and compare the results with those obtained using the original asymptotic theory. We find that quasi-steady relations between detonation velocity and curvature calculated using the proposed theory are in better agreement with numerical calculations than the original theory. We also use an equation of state that realistically represents condensed phase explosives, and two composition variables to track reaction and compaction processes, to perform calculations of quasi-steady relations between detonation velocity and curvature, detonation shock acceleration fields as a function of detonation velocity and curvature, and the dynamics of ignition events in solid PBX9501 and in PETN powders. We compare our results with numerical calculations of detonation shock dynamics and direct numerical simulations. We find that the time it takes an ignition wave to become quasi-steady is short, explaining why the quasi-steady relation between the detonation velocity and curvature can sometimes be a good approximation for a speed rule.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 9

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The research carried out under this grant was on 1) the analytical theory of detonation stability and 2) the development of new models for description of the mechanical ignition of condensed explosives. The research directly and indirectly supported a separate effort at UIUC on the engineering design of explosive systems, specifically condensed phase explosives and the use of related numerical technologies.

Author: Charles L. Mader
Publisher: CRC Press
ISBN: 9780849331497
Category : Technology & Engineering
Languages : en
Pages : 456

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Book Description
Charles Mader, a leading scientist who conducted theoretical research at Los Alamos National Laboratory for more than 30 years, sets a new standard with this reference on numerical modeling of explosives and propellants. This book updates and expands the information presented in the author's landmark work, Numerical Modeling of Detonations, published in 1979 and still in use today. Numerical Modeling of Explosives and Propellants incorporates the considerable changes the personal computer has brought to numerical modeling since the first book was published, and includes new three-dimensional modeling techniques and new information on propellant performance and vulnerability. Both an introduction to the physics and chemistry of explosives and propellants and a guide to numerical modeling of detonation and reactive fluid dynamics, Numerical Modeling of Explosives and Propellants offers scientists and engineers a complete picture of the current state of explosive and propellant technology and numerical modeling. The book is richly illustrated with figures that support the concepts, and filled with tables for quick access to precise data. The accompanying CD-ROM contains computer codes that are the national standard by which modeling is evaluated. Dynamic material properties data files and animation files are also included. There is no other book available today that offers this vital information.

Author: James Taylor
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 218

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Author: K. Ramamurthi
Publisher: Springer Nature
ISBN: 3030743381
Category : Technology & Engineering
Languages : en
Pages : 408

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b="" The book provides a concise description of the physical processes and mathematical models for explosions and formation of blast waves from explosions. The contents focus on quantitatively determining the energy released in the different types of explosions and the destructive blast waves that are generated. The contribution of flames, detonations and other physical processes to the explosion phenomenon is dealt with in detail. Gaseous and condensed phase explosions are discussed and the yield of explosions with their TNT equivalence is determined. Time scales involved in the explosion process and the scaling procedure are ascertained. Explosions over the ground, in water, and the interaction of explosions with objects are examined. In order to keep the text easily readable, the detailed derivation of the mathematical equations is given in the seven appendices at the end of the book. Case studies of various explosions are investigated and simple problems and their solutions are provided for the different topics to assist the reader in internalizing the explosion process. The book is a useful reference for professionals and academics in aeronautics, mechanical, civil and chemical engineering and for personnel working in explosive manufacture and high-energy materials, armaments, space, defense, and industrial and fire safety.

Author: Roger Cheret
Publisher: Springer Science & Business Media
ISBN: 1461392845
Category : Science
Languages : en
Pages : 442

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Book Description
This work marks a stage in the evolution of a scientific and technical field which has been developed by the Commissariat a l'Energie Atomique (CEA) over several decades. Many members of the staff of the CEA have won re nown in this field, and their work has brought it to the high degree of excel lence for which it is internationally recognized today. These scientists had to consider every aspect of the field, as it concerned: modeling, which has recourse to fluid thermodynamics, molecular phys ics, and chemistry; numerical evaluation, which relies on mathematical analysis and data processing; and experiments in the firing area, which require specific stress generators and instrumentation. Whilst this book is a testament to the activity and success of staff of the CEA, it also reviews a number ofthe advances made in the discipline. How ever, it is not intended to be an exhaustive account of those advances; it is assumed that the reader can, if desired, consult the standard monographs, and more recent, more specialized works (notably W.C. Davis and W. Fickett, and C.L. Mader). The history of the discipline is interesting in itself, and also as an illustra tion of the causes which lead to progress in a coherent body of scientific work. I should like to make some comments on this progress, of which there is a fascinating summary in the introduction, and which will figure largely throughout the work.

Author: Aleksandr Fedorovich Beli︠a︡ev
Publisher:
ISBN:
Category : Combustion
Languages : en
Pages : 260

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Previous ed.: Izdatel'stvo Nauka, Moskva, 1973.

Author: Shiro Kubota
Publisher: Springer Nature
ISBN: 9811953074
Category : Science
Languages : en
Pages : 298

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Book Description
This book presents fundamental theory of shock and detonation waves as well as selected studies in detonation research in Japan, contributed by selected experts in safety research on explosives, development of industrial explosives, and application of explosives. It also reports detonation research in Japan featuring industrial explosives that include ammonium nitrate-based explosives and liquid explosives. Intended as a monographic-style book, it consistently uses technical terms and symbols and creates organic links between various detonation phenomena in application of explosives, fundamental theory of detonation waves, measurement methods, and individual studies. Among other features, the book presents a historical perspective of shock wave and detonation research in Japan, pedagogical materials for young researchers in detonation physics, and an introduction to works in Japan, including equations of state, which are worthy of attention but about which very little is known internationally. Further, the concise pedagogical chapters also characterize this book as a primer of detonation of condensed explosives and help readers start their own research.