Arrhenius Rate Chemistry Informed Inter-phase Source Terms (ARCIIST) for Macro-Scale Explosive Hydrocodes

A critical factor in hydrocodes designed to simulate explosive material is defining the chemical reaction rate under various conditions. This rate determines how quickly the granular solid explosive is converted to its gaseous products. Currently, the state of the art for macro-scale hydrocodes is to use one of numerous burn models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these burn rate models are largely based on empirical data and must be recalibrated for every new material being simulated. This research proposes that the use of Arrhenius Rate Chemistry Informed Interphase Source Terms (ARCIIST) in place of these burn models will not only reduce the reliance of simulations on empirically derived data but will also improve the accuracy for these computational codes. ARCIIST was tested by incorporating an Arrhenius reacting chemistry model developed for the cyclic-nitramine RDX by the Naval Research Laboratory (NRL) into the Air Force Research Laboratory\u27s (AFRL) Multi-Phase Explosive Simulation (MPEXS) continuum hydrocode. ARCIIST demonstrated a unique ability to capture critical features in the deflagration to detonation transition process which were washed out by the common pressure-dependent burn models sunder the same conditions. Furthermore, ARCIIST has successfully linked micro-scale chemical kinetics to macro-scale hydrodynamics. It is, therefore, a critical piece to connecting predictive theoretical chemical kinetics to system scale simulations with less reliance on empirical data

Characterization and Discrimination of Large Caliber Gun Blast and Flash Signatures

Two hundred and one firings of three 152 mm howitzer munitions were observed to characterize firing signatures of a large caliber gun. Muzzle blast expansion was observed with high-speed (1600 Hz) optical imagery. The trajectory of the blast front was well approximated by a modified point-blast model described by constant rate of energy deposition. Visible and near-infrared (450 - 850 nm) spectra of secondary combustion were acquired at 0.75 nm spectral resolution and depict strong contaminant emissions including Li, Na, K, Cu, and Ca. The O2 (X-b) absorption band is evident in the blue wing of the potassium D lines and was used for monocular passive ranging accurate to within 4 - 9%. Time-resolved midwave infrared (1800 - 6000 cm-1) spectra were collected at 100 Hz and 32 cm-1 resolution. A low dimensional radiative transfer model was used to characterize plume emissions in terms of area, temperature, soot emissivity, and species concentrations. Combustion emissions have 100 ms duration, 1200 - 1600 K temperature, and are dominated by H2O and CO2. Noncombusting plume emissions last 20 ms, are 850 - 1050 K, and show significant continuum (emissivity 0.36) and CO structure. Munitions were discriminated with 92 - 96% classification accuracy using only 1 - 3 firing signature features

Thermal neutron analysis for improvised explosive device detection

In this dissertation, the design of a system to detect improvised explosive devices is considered. The technique utilized is thermal neutron analysis. In this method, thermal neutrons are used to interrogate a volume for the presence of nitrogen, which is used as an indicator of explosive, given its unusual high energy line in the gamma ray spectrum generated by thermal capture reactions on explosive material. The performance of the system is then considered for a number of devices used to represent an improvised explosive device, including a 155 mm shell, an antitank mine, and a air to surface bomb. The system is shown to be capable of detecting IEDs within between 15.6 and 3800 seconds for HPGe detectors, and within 277 seconds for the best case scenario with NaI while more deeply buried explosives are shown to be undetectable by NaI

Cryocycling of Energetic Materials: Final Report

The Cryocycling of Energetic Materials Project was executed in the period FY`94-96 as a Life Cycle Engineering activity in the Memorandum of Understanding (MOU) on advanced conventional munitions. This MOU is an agreement between the Departments of Energy and Defense (Office of Munitions) that facilitates the development of technologies of mutual interest to the two Departments. The cryocycling process is a safe, environmentally friendly, and cost effective means of rubblizing bulk energetic materials so that they can be easily reused in a variety of new products. For this reason, cryocycling of excess solid energetic materials is one of the recycle/reuse strategies under study for demilitarized munitions in the Departments of Energy and Defense. These strategies seek to minimize the environmental damage associated with disposal of decommissioned energetic materials. In addition, they encourage technologies that can be used to derive economic benefit from reuse/reapplication of materials that would otherwise be treated as hazardous wastes. 45 refs., 38 figs., 7 tabs

Pressure Systems Energy Release Protection (Gas Pressurized Systems)

A survey of studies into hazards associated with closed or pressurized system rupture and preliminary guidelines for the performance design of primary, secondary, and protective receptors of these hazards are provided. The hazards discussed in the survey are: blast, fragments, ground motion, heat radiation, biological, and chemical. Performance guidelines for receptors are limited to pressurized systems that contain inert gas. The performance guidelines for protection against the remaining unaddressed degenerative hazards are to be covered in another study

Indexes of the Proceedings for the Ten International Symposia on Detonation 1951-93

The Proceedings of the ten Detonation Symposia have become the major archival source of information of international research in explosive phenomenology, theory, experimental techniques, numerical modeling, and high-rate reaction chemistry. In many cases, they contain the original reference or the only reference to major progress in the field. For some papers, the information is more complete than the complementary article appearing in a formal journal; yet for others, authors elected to publish only an abstract in the Proceedings. For the large majority of papers, the Symposia Proceedings provide the only published reference to a body of work. This report indexes the ten existing Proceedings of the Detonation Symposia by paper titles, topic phrases, authors, and first appearance of acronyms and code names

DRONE DELIVERY OF CBNRECy – DEW WEAPONS Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD)

Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD) is our sixth textbook in a series covering the world of UASs and UUVs. Our textbook takes on a whole new purview for UAS / CUAS/ UUV (drones) – how they can be used to deploy Weapons of Mass Destruction and Deception against CBRNE and civilian targets of opportunity. We are concerned with the future use of these inexpensive devices and their availability to maleficent actors. Our work suggests that UASs in air and underwater UUVs will be the future of military and civilian terrorist operations. UAS / UUVs can deliver a huge punch for a low investment and minimize human casualties.https://newprairiepress.org/ebooks/1046/thumbnail.jp