Download or read book Numerical Modeling of One dimensional Discrete Source Detonation written by Mehshan Javaid and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modelling of One dimensional Discrete Source Detonation written by Mehshan Javaid and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Explosives and Propellants Second Edition written by Charles L. Mader and published by CRC Press. This book was released on 1997-08-29 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Numerical Simulation of Transition to Detonation written by MATERIALS RESEARCH LABS ASCOT VALE (Australia) and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a physical model of the detonation process in homogeneous materials and details of the numerical scheme chosen to solve the coupled nonlinear partial differential equations which describe the model. In one dimension the model can be solved analytically, and in this case a detailed comparison is made between the analytical and numerical results, and excellent agreement is obtained. The effect of the computational cell size on the accuracy of the numerical solutions is illustrated, and a new technique for limiting the temperature overshoot which occurs if there is insufficient resolution of the reaction zone is presented. Two dimensional calculations of the diffraction which occur when a gaseous detonation propagates past a step or an increase in cross-sectional area are also described.

Download or read book Detonation in Spatially Inhomogeneous Media written by XiaoCheng Mi and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Detonation propagation in a compressible medium wherein the energy release has been made spatially inhomogeneous is examined via numerical simulations. The inhomogeneity is introduced via concentrating reactive material into regions which are separated by inert gaps while maintaining the same average energy density. The propagation velocity and propagation limit of detonation waves under the influence of these imposed inhomogeneities are put to a rigorous examination.Spatial inhomogeneities are introduced to adiabatic detonation systems with a hierarchy of complexities. In a system governed by one-dimensional Euler equations with a simplified mechanism of instantaneous energy deposition, i.e., a source triggered by the passage of leading shock after a prescribed delay time, the resulting averaged propagation speed over hundreds of spatially discrete sources is compared to the ideal Chapman-Jouguet (CJ) speed for an equivalent amount of energy release. Velocities in excess of the CJ speed are found as the reactive regions are made increasingly discrete, with deviation above CJ being as great as 15%. The deviation above the CJ value increases with decreasing values of specific heat ratio [gamma]. When the sources are sufficiently spread out so as to make the energy release of the media nearly continuous, the classic CJ solution is obtained for the average wave speed. In the limit of highly discrete sources, time-averaged mean wave structure shows that the effective sonic surface does not correspond to an equilibrium state. The average state of the flow leaving the wave in this case does eventually reach the equilibrium Hugoniot, but only after the effective sonic surface has been crossed. Thus, the super-CJ waves observed in the limit of highly discretized sources can be understood as weak detonations due to the non-equilibrium state at the effective sonic surface. The investigation on how detonation velocity is influenced by the presence of spatial inhomogeneities is then extended to one- and two-dimensional systems with a more realistic mechanism of energy release, i.e., single-step Arrhenius kinetics. In the case of sufficiently inhomogeneous media wherein the spacing between the reactive zones is greater than the inherent reaction zone length, average wave speeds significantly greater than the corresponding CJ speed of the homogenized medium are obtained. If the shock transit time between reactive zones is less than the reaction time scale, then the classical CJ detonation velocity is recovered. The super-CJ wave propagation is also identified in the cases with a two-dimensional arrangement of spatial inhomogeneities. The correspondence of the super-CJ behavior identified in this study with real detonation phenomena that may be observed in experiments is discussed. Finally, a random distribution of spatially discrete sources is implemented into a two-dimensional detonation system confined by an inert, compressible layer of gas. In this system, detonation waves experience losses due to lateral expansion behind a curved shock front and, thus, propagate at a velocity lower than the ideal CJ velocity. As the thickness of the reactive layer within the confinement decreases, the deficit in propagation velocity increases; below a critical thickness, detonations can no longer propagate in a self-sustained manner. The critical thickness for a steady propagation is determined for a homogeneous reactive medium and a mixture with randomly distributed, discrete reactive sources. The simulation results show that, for a sufficiently high activation energy, the spatial inhomogeneities assist a detonation wave to propagate beyond the limit that is encountered in a homogeneous reactive medium. This enhancing effect of the spatial inhomogeneities on the near-limit propagation of detonation waves is found to be more pronounced with increasing activation energy." --

Download or read book Numerical Modeling of Detonation with Discrete Microstructure and Local Reactions written by and published by . This book was released on 2012 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Detonation Initiation by the Space time Conservation Element and Solution Element Method written by Bao Wang and published by . This book was released on 2010 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This dissertation is focused on the numerical simulation of the detonation initiation process. The space-time Conservation Element and Solution Element (CESE) method, a novel numerical method for time-accurate solutions of nonlinear hyperbolic equations, is extended to model conservation laws with stiff source terms for the detonation initiation process with multiple-step, finite-rate chemistry. The first part of the dissertation illustrates the numerical framework for unsteady chemically reacting flows by incorporating multiple-step, finite-rate chemical mechanisms using the CESE method. One- and two-dimensional solvers have been developed. Extensive code validation and verification are provided for the one- and two-dimensional CESE solvers. The second part focuses on the numerical investigation of the detonation initiation process. The numerical framework is first applied to the direct initiation of gaseous detonations by a blast wave. One-dimensional cylindrical and spherical direct initiation processes in a hydrogen-oxygen mixture are studied with a twenty-four step chemical reaction model. Structures of unsteady reaction zone are clearly resolved. The competition between heat release rate, front curvature, and unsteadiness is investigated. Detailed wave movements in the detonation wave front show that nonlinear waves play an important role in the reacceleration process and are the key to understanding the detonation failure mechanism. The detonation initiation process by implosion shock is then investigated. Shock focusing and shock interactions in the detonation initiation process are examined. Results show a two-shock implosion system due to the interaction between the reflected primary shock and the imploding contact discontinuity. Oblique detonation is studied for the code verification and validation of the two-dimensional CESE solvers. Stabilized detonation structures are resolved and the length of the induction zone is compared with point ignition test data. Implosion with polygonal shock fronts is then explored. Similar to the findings in the one-dimensional results, pressure histories in the focal region show multiple implosions. This Ph. D. study work applies the very accurate and efficient CESE method to study detonation initiation processes. The resultant solvers are state-of-the-art numerical codes that are ready to be applied to time-accurate solutions of detonation initiation processes. This approach provides a new numerical framework for high-fidelity simulations of detonation initiation.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Detonation in Condensed Phase Explosives written by D. A. Jones and published by . This book was released on 1998 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulations of One dimensional Detonation Waves Using a Total Variation Diminishing Scheme written by Ryan Edward Pfeiffer and published by . This book was released on 1998 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Instability of Steady and Quasi steady Detonations written by Brian D. Taylor and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The stability properties and dynamic behavior of steady and quasi-steady detonation theories are investigated through linear stability analysis and numerical simulation. A general, unsteady, three-dimensional formulation of the reactive Euler equations in a shock-fitted reference frame is derived. The formulation is specialized to three configurations: planar one-dimensional detonation, radially symmetric one-dimensional detonation, and two-dimensional detonation in a rectangular channel. High-order convergent numerical simulation schemes for these configurations are derived and used to study the linear and nonlinear stability of detonations. Shock-fitted numerical simulation is used to study the two-dimensional instability of steady solutions to the Zel'dovich, von Neumann, and Doring (ZND) model of detonation. It is demonstrated through several methods of analysis that the dependence of instability growth rates and oscillation frequencies on the initial disturbance wavelength, as predicted by linear stability theory, is quantitatively reproduced by shock-fitted simulations. Agreement with the theorized temporal and spatial structure of the instability is demonstrated by a functional expansion of the solution perturbations, obtained from simulation data, in terms of the linear stability eigenfunctions. Three regimes of unstable behavior - linear, weakly non-linear, and fully non-linear - are explored and characterized in terms of the power spectrum of the normal detonation velocity. Using solutions obtained from Detonation Shock Dynamics (DSD) theory, the behavior of cylindrically and spherically expanding symmetric detonations is studied by one-dimensional shock-fitted numerical simulation. We consider idealized models of gaseous and condensed phase detonation, as well as a realistic model calibrated for the high explosive PBX-9501. We study the behavior of detonations initialized with solutions of DSD as they expand radially. The various models and calibrations exhibit regimes of hydrodynamic stability, in which the detonation evolves slowly in time and agreement with DSD theory is good, and regimes of instability, which in some cases leads to failure of the detonation wave.

Download or read book Mathematical Modelling and Numerical Simulation of Oil Pollution Problems written by Matthias Ehrhardt and published by Springer. This book was released on 2015-03-10 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by outstanding experts in the fields of marine engineering, atmospheric physics and chemistry, fluid dynamics and applied mathematics, the contributions in this book cover a wide range of subjects, from pure mathematics to real-world applications in the oil spill engineering business. Offering a truly interdisciplinary approach, the authors present both mathematical models and state-of-the-art numerical methods for adequately solving the partial differential equations involved, as well as highly practical experiments involving actual cases of ocean oil pollution. It is indispensable that different disciplines of mathematics, like analysis and numerics, together with physics, biology, fluid dynamics, environmental engineering and marine science, join forces to solve today’s oil pollution problems. The book will be of great interest to researchers and graduate students in the environmental sciences, mathematics and physics, showing the broad range of techniques needed in order to solve these pollution problems; and to practitioners working in the oil spill pollution industry, offering them a professional reference resource.

Download or read book Identification of Seismic Sources Earthquake or Underground Explosion written by Eystein S. Husebye and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 867 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this NATO Advanced Study Institute was seismic monitoring under a nuclear test ban - an application of scienti fic knowledge and modern technology for a political purpose. The international political objective of a comprehensive nuclear test ban provided in turn the motivation for our technical and scientific discussions. In order to obtain a historical perspec tive on the progress of the work towards a comprehensive test-ban treaty (CTB), it is necessary to go back to 1958, when a confer ence of scientific experts in Geneva made the first steps toward an international seismic monitoring system. However, agreement on actual capabilities of a monitoring system for verifying compliance with such a treaty was not achieved, and thus the conference did not lead to immediate political results. After the Partial Test Ban Treaty of 1963, which banned nuclear explosions in the atmosphere, outer space and under the seas, renewed interest in the seismological verification of a CTB took place. A number of countries initiated large-scale research efforts toward detecting and identifying underground nuclear explosions, and it was in this context that the large aperture seismic arrays NORSAR and LASA were established. This type of development resulted in excellent seismic data in digital form and was thus of great irnprotance to the seismological com munity.

Download or read book One dimensional Dense Fluid Detonation written by Mohamed Safwat I. Abdelazim and published by . This book was released on 1982 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Detonations written by Charles L. Mader and published by . This book was released on 1979 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Numerical Computation of One dimensional Detonation Waves written by Adriaan Cornelis Berkenbosch and published by . This book was released on 1994 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment of Numerical Issues in One dimensional Detonation Wave Representation written by Ramanan Sankaran and published by . This book was released on 2000 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: