Download or read book Shock Initiation of Modeling Multicomponent Explosives written by and published by . This book was released on 1977 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Initiation Modeling of Multicomponent Explosives written by Yehuda Partom and published by . This book was released on 1989 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Modeling of Explosives and Propellants written by Charles L. Mader and published by CRC Press. This book was released on 2007-10-18 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: Major advances, both in modeling methods and in the computing power required to make those methods viable, have led to major breakthroughs in our ability to model the performance and vulnerability of explosives and propellants. In addition, the development of proton radiography during the last decade has provided researchers with a major new experimental tool for studying explosive and shock wave physics. Problems that were once considered intractable – such as the generation of water cavities, jets, and stems by explosives and projectiles – have now been solved. Numerical Modeling of Explosives and Propellants, Third Edition provides a complete overview of this rapidly emerging field, covering basic reactive fluid dynamics as well as the latest and most complex methods and findings. It also describes and evaluates Russian contributions to the experimental explosive physics database, which only recently have become available. This book comes with downloadable resources that contain— · FORTRAN and executable computer codes that operate under Microsoft® Windows Vista operating system and the OS X operating system for Apple computers · Windows Vista and MAC compatible movies and PowerPoint presentations for each chapter · Explosive and shock wave databases generated at the Los Alamos National Laboratory and the Russian Federal Nuclear Centers Charles Mader’s three-pronged approach – through text, computer programs, and animations – imparts a thorough understanding of new computational methods and experimental measuring techniques, while also providing the tools to put these methods to effective use.
Download or read book Three Dimensional Modeling of Shock Initiation of Heterogeneous Explosives written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic processes in the shock initiation of heterogeneous explosives have been investigated theoretically using a model of a cube of nitromethane containing 91 cubic air holes. The interaction of a shock wave with the density discontinuities, the resulting hot spot formation and interaction, and the buildup to propagating detonation were computed using three-dimensional numerical Eulerian hydrodynamics with Arrhenius chemical reaction and accurate equations of state. The basic process in the desensitization of a heterogeneous explosive by preshocking with a shock pressure too low to cause propagating detonation was numerically modeled.
Download or read book Surface burn Model for Shock Initiation written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of a surface-burn of the shock-induced decomposition initiation and detonation of heterogeneous explosives is described. The model assumes a microscale process with hot spots ignited by viscoplastic heating at the boundaries of collapsing pores. A relatively thin reaction zone, or burn surface, is driven by the conduction of the heat of reaction, and has a surface-burn velocity with an Arrhenius dependence on the temperature of the unreacted solid component. Global reaction rates are derived from the microscale model with an empirical burning topology function and a macroscopic reactant-product mixture defined by pressure equilibrium, ideal mixing of specific volume and internal energy, and isentropic response of the unreacted constituents. With simplifying assumptions, the model is extended to treat multi-component explosives. The model is implemented into a method of characteristics hydrocode and shown to be effective in simulating several examples of initiation experiments on TATB explosives. 10 refs., 9 figs.
Download or read book Modeling Shock Initiation in Composition B written by and published by . This book was released on 1993 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A hydrodynamic modeling study of the shock initiation behavior of Composition B explosive was performed using the {open_quotes}Ignition and Growth of Reaction in High Explosive{close_quotes} model developed at the Lawrence Livermore National Laboratory. The HE (heterogeneous explosives) responses were computed using the CALE and DYNA2D hydrocodes and then compared to experimental results. The data from several standard shock initiation and HE performance experiments was used to determine the parameters required for the model. Simulations of the wedge tests (pop plots) and failure diameter tests were found to be sufficient for defining the ignition and growth parameters used in the two term version of the computational model. These coefficients were then applied in the response analysis of several Composition B impact initiation experiments. A description of the methodology used to determine the coefficients and the resulting range of useful application of the ignition and growth of reaction model is described.
Download or read book SHOCK INITIATION EXPERIMENTS AND MODELING OF COMPOSITION B AND C 4 written by F. Garcia and published by . This book was released on 2006 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock initiation experiments on the explosives Composition B and C-4 were performed to obtain in-situ pressure gauge data for the purpose of determining the Ignition and Growth reactive flow model with proper modeling parameters. A 101 mm diameter propellant driven gas gun was utilized to initiate the explosive charges containing manganin piezoresistive pressure gauge packages embedded in the explosive sample. Experimental data provided new information on the shock velocity versus particle velocity relationship for each of the investigated materials in their respective pressure range. The run-distance-to-detonation points on the Pop-plot for these experiments showed agreement with previously published data, and Ignition and Growth modeling calculations resulted in a good fit to the experimental data. These experimental data were used to determine Ignition and Growth reactive flow model parameters for these explosives. Identical ignition and growth reaction rate parameters were used for C-4 and Composition B, and the Composition B model also included a third reaction rate to simulate the completion of reaction by the TNT component. The Composition B model was then tested on existing short pulse duration, gap test, and projectile impact shock initiation with good results. This Composition B model can be applied to shock initiation scenarios that have not or cannot be tested experimentally with a high level of confidence in its predictions.
Download or read book SHOCK INITIATION OF COMPOSITION B AND C 4 EXPLOSIVES EXPERIMENTS AND MODELING written by F. Garcia and published by . This book was released on 2006 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock initiation experiments on the explosives Composition B and C-4 were performed to obtain in-situ pressure gauge data for the purpose of providing the Ignition and Growth reactive flow model with proper modeling parameters. A 100 mm diameter propellant driven gas gun was utilized to initiate the explosive charges containing manganin piezoresistive pressure gauge packages embedded in the explosive sample. Experimental data provided new information on the shock velocity--particle velocity relationship for each of the investigated material in their respective pressure range. The run-distance-to-detonation points on the Pop-plot for these experiments showed agreement with previously published data, and Ignition and Growth modeling calculations resulted in a good fit to the experimental data. Identical ignition and growth reaction rate parameters were used for C-4 and Composition B, and the Composition B model also included a third reaction rate to simulate the completion of reaction by the TNT component. This model can be applied to shock initiation scenarios that have not or cannot be tested experimentally with a high level of confidence in its predictions.
Download or read book Numerical Calculation of Shock induced Initiation of Detonations PBX 9501 written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of some numerical calculations of the impact of steel cylinders and spheres on the plastic-bonded high explosive PBX 9501 are described. The calculations were carried out by a reactive, multicomponent, two-dimensional, Eulerian hydrodynamic computer code, 2DE. The 2DE computer code is a finite difference code that uses the donor-acceptor-cell method to compute mixed cell fluxes. The mechanism of shock initiation to detonation in heterogeneous explosives is best described as local decomposition at hot spots that are formed by shock interactions with density discontinuities. The liberated energy strengthens the shock so that as it interacts with additional inhomogeneities, hotter hot spots are formed, and more of the explosive is decomposed. The shock wave grows stronger until a detonation begins. This mechanism of initiation has been described numerically by the Forest Fire burn model, which gives the rate of explosive decomposition as a function of local pressure. The parameters in the Forest Fire burn model have been developed from experiments where the induced shock approximates a plane wave and are applied, in this case, to a situation where the induced shock is a divergent wave with curvature that depends on the size and shape of the projectile. The calculated results have been compared with results from experiments involving instrumented mock and live high explosives, with projectiles of varying sizes, shapes, and velocities. We find that there is good agreement between the calculated and experimental data.
Download or read book Modeling Explosions and Blast Waves written by K. Ramamurthi and published by Springer Nature. This book was released on 2021-06-19 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Shock Initiation Modelling of Explosives written by H. J. Verbeek and published by . This book was released on 1997 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Simplistic Approach to the Shock Initiation of Detonation in Heterogeneous Explosives written by Philip M. Howe and published by . This book was released on 1972 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model of the shock initiation of heterogeneous explosives is presented. The model is based upon a 'hotspot' ignition mechanism. Choice of the energy density as the independent variable in the problem permits separation of Hugoniot effects from the buildup process, and leads to a critical condition for initiation which is independent of the loading density. The model is found to be consistent with data from the literature on porous tetryl. (Author).
Download or read book Shock Wave Science and Technology Reference Library Vol 5 written by Blaine Asay and published by Springer Science & Business Media. This book was released on 2009-12-16 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Los Alamos National Laboratory is an incredible place. It was conceived and born amidst the most desperate of circumstances. It attracted some of the most brilliant minds, the most innovative entrepreneurs, and the most c- ative tinkerers of that generation. Out of that milieu emerged physics and engineering that beforehand was either unimagined, or thought to be f- tasy. One of the ?elds essentially invented during those years was the science of precision high explosives. Before 1942, explosives were used in munitions and commercial pursuits that demanded proper chemistry and con?nement for the necessary e?ect, but little else. The needs and requirements of the Manhattan project were of a much more precise and speci?c nature. Spatial and temporal speci?cations were reduced from centimeters and milliseconds to micrometers and nanoseconds. New theory and computational tools were required along with a raft of new experimental techniques and novel ways of interpreting the results. Over the next 40 years, the emphasis was on higher energy in smaller packages, more precise initiation schemes, better and safer formulations, and greater accuracy in forecasting performance. Researchers from many institutions began working in the emerging and expanding ?eld. In the midst of all of the work and progress in precision initiation and scienti?c study, in the early 1960s, papers began to appear detailing the ?rst quantitative studies of the transition from de?agration to detonation (DDT), ?rst in cast, then in pressed explosives, and ?nally in propellants.
Download or read book Molecular Level Modeling of the Mechanism of Shock Initiation of Solid Explosives written by F. J. Owens and published by . This book was released on 1980 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work represents an attempt to consider on a fundamental level how shock or impact can cause chemical reactions in certain solids in order to gain insight into the factors which determine sensitivity to explosion.
Download or read book Numerical Modeling of the Effect of Particle Size of Explosives on Shock Initiation Properties written by Charles L. Mader and published by . This book was released on 1988 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Constitutive Modeling of Weak and Strong Shock initiation of Porous Explosives written by and published by . This book was released on 1998 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: A continuum based reactive burn model for shocked loaded high explosives has been developed that uses heterogeneous distribution of pore collapse energy to one or more of the constituents (a hot spot) as an ignition source, represents constituents with independent equations of state and has multiple competing and sequential chemical reactions. Reaction propagates from the hot spot to the remainder of the material through either a pressure or temperature dependence of heat transfer through a film layer. The reaction may be quenched by heat transfer or shock release if it is not rapid enough.
