Numerical Modeling of Explosives and Propellants, Second Edition


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.




Surface-burn Model for Shock Initiation


Book Description

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.




Three Dimensional Modeling of Shock Initiation of Heterogeneous Explosives


Book Description

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.




Shock Wave Science and Technology Reference Library, Vol. 5


Book Description

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.







Modeling Shock Initiation in Composition B.


Book Description

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.