Simulation of Enhanced-Explosive Devices in Chambers and Tunnels

Simulation of Enhanced-Explosive Devices in Chambers and Tunnels
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Total Pages: 10
Release: 2007
Genre:
ISBN:
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Introduction: Shock-dispersed fuel (SDF) explosives use a small chemical charge to disperse a combustible fuel that burns in the post-detonation environment. The energy released in the combustion process has the potential for generating higher pressures and temperatures than conventional explosives. However, the development of these types of novel explosive systems requires a detailed understanding of all of the modes of energy release. Objective: The objective of this project is develop a simulation capability for predicting explosion and combustion phase of SDF charges and apply that capability to quantifying the behavior of these types of explosives. Methodology: We approximate the dynamics of an SDF charge using high Reynolds number, fast chemistry model that effectively captures the thermodynamic behavior of SDF charges and accurately models the key modes of energy release. The overall computational model is combined with Adaptive Mesh Refinement (AMR), implemented in a parallel adaptive framework suited to the massively parallel computer systems. Results: We have developed a multiphase version of the model and used it to simulate an SDF charge in which the dispersed fuel is aluminum flakes. Flow visualizations show that the combustion field is turbulent for the chamber and tunnel cases studied. During the 3 milli-seconds of simulation, over 90% of the Al fuel was consumed for the chamber case, while about 40% was consumed in the tunnel case in agreement with Al-SDF experiments. Significance to DoD: DoD has a requirement to develop enhanced energetic materials to support future military systems. The SDF charges described here utilize the combustion mechanism to increase energy per gram of fuel by a factor of 7 to 10 over conventional (detonating) charges, and increase the temperature of the explosion cloud to 2,000-4,000 K (depending on the SDF fuel). Accurate numerical simulation of such SDF explosions allows one to understand the energy release mechanism, and thereby design full-scale systems with greatly improved explosive efficiency.

Coarse Grained Simulation and Turbulent Mixing

Coarse Grained Simulation and Turbulent Mixing
Author: Fenando F. Grinstein
Publisher: Cambridge University Press
Total Pages: 481
Release: 2016-06-30
Genre: Science
ISBN: 1107137047
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Reviews our current understanding of the subject. For graduate students and researchers in computational fluid dynamics and turbulence.

Spatial Modelling and Failure Analysis of Natural and Engineering Disasters through Data-Based Methods,volume III

Spatial Modelling and Failure Analysis of Natural and Engineering Disasters through Data-Based Methods,volume III
Author: Faming Huang
Publisher: Frontiers Media SA
Total Pages: 243
Release: 2024-09-12
Genre: Science
ISBN: 2832554237
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This Research Topic is Volume III of a series. The previous volume can be found here: Spatial Modelling and Failure Analysis of Natural and Engineering Disasters through Data-based Methods - Volume II and Spatial Modelling and Failure Analysis of Natural and Engineering Disasters through Data-based Methods Natural and engineering disasters, which include landslides, rock fall, rainstorm, dam failure, floods, earthquakes, road and building disasters and wildfires, appear as results of the progressive or extreme evolution of climatic, tectonic and geomorphological processes and human engineering activities. It is significant to explore the failure mechanism and carry out spatial modeling of these engineering and natural disasters due to their serious harm to the safety of people's lives and property. The data-based methods, including advanced and successful remote sensing, geographic information systems, machine learning and numerical simulation techniques methods, are promising tools to analyze these complex disasters. Machine Learning models such as neurofuzzy logic, decision tree, artificial neural network, deep learning and evolutionary algorithms are characterized by their abilities to produce knowledge and discover hidden and unknown patterns and trends from large databases, whereas remote sensing and Geographic Information Systems appear as significant technology equipped with tools for data manipulation and advanced mathematical modeling. What is more, the numerical simulation can also be acknowledged as advanced technologies for discovering hidden failure mechanism of disasters. The main objective of this Research Topic is to provide a scientific forum for advancing the successful implementation of Machine Learning (ML) and numerical simulation techniques in operation rules, failure mechanism, spatial and time series prediction, susceptibility mapping, hazard assessment, vulnerability modeling, risk assessment and early warning of complex natural and engineering disasters.

NASA Tech Brief

NASA Tech Brief
Author:
Publisher:
Total Pages: 792
Release: 1970
Genre: Aeronautics
ISBN:
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Explosive Loading of Engineering Structures

Explosive Loading of Engineering Structures
Author: P.S. Bulson
Publisher: CRC Press
Total Pages: 269
Release: 1997-07-24
Genre: Architecture
ISBN: 0203473868
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This book reviews the development of research into the explosive loading of structures, mainly since the beginning of the twentieth century. Major contributions in the fields of measurement, analysis and prediction are discussed. Dynamic loading from conventional high explosives is examined, as well as the effects of liquid propellant, dust, gas, v

Gaseous Detonation Physics and Its Universal Framework Theory

Gaseous Detonation Physics and Its Universal Framework Theory
Author: Zonglin Jiang
Publisher: Springer Nature
Total Pages: 281
Release: 2022-12-16
Genre: Science
ISBN: 9811970025
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This book highlights the theories and research progress in gaseous detonation research, and proposes a universal framework theory that overcomes the current research limitations. Gaseous detonation is an extremely fast type of combustion that propagates at supersonic speed in premixed combustible gas. Being self-sustaining and self-organizing with the unique nature of pressure gaining, gaseous detonation and its gas dynamics has been an interdisciplinary frontier for decades. The research of detonation enjoyed its early success from the development of the CJ theory and ZND modeling, but phenomenon is far from being understood quantitatively, and the development of theories to predict the three-dimensional cellular structure remains a formidable task, being essentially a problem in high-speed compressible reacting flow. This theory proposed by the authors’ research group breaks down the limitation of the one-dimensional steady flow hypothesis of the early theories, successfully correlating the propagation and initiation processes of gaseous detonation, and realizing the unified expression of the three-dimensional structure of cell detonation. The book and the proposed open framework is of high value for researchers in conventional applications such as coal mine explosions and chemical plant accidents, and state-of-the-art research fields such as supernova explosion, new aerospace propulsion engines, and detonation-driven hypersonic testing facilities. It is also a driving force for future research of detonation.

NASA's Contributions to Aeronautics: Aerodynamics, structures, propulsion, controls

NASA's Contributions to Aeronautics: Aerodynamics, structures, propulsion, controls
Author:
Publisher:
Total Pages: 980
Release: 2010
Genre: Aeronautics
ISBN:
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Two-volume collection of case studies on aspects of NACA-NASA research by noted engineers, airmen, historians, museum curators, journalists, and independent scholars. Explores various aspects of how NACA-NASA research took aeronautics from the subsonic to the hypersonic era.-publisher description.