Bulletin of the American Physical Society
16th APS Topical Conference on Shock Compression of Condensed Matter
Volume 54, Number 8
Sunday–Friday, June 28–July 3 2009; Nashville, Tennessee
Session C1: EM-2: Explosive Effects |
Hide Abstracts |
Chair: Clare Bauer, AWE Room: Tennessee Ballroom |
Monday, June 29, 2009 11:00AM - 11:15AM |
C1.00001: Enhanced Blast Effects of Reactive Structural Materials Used For Cased Explosives William Wilson, L.V. Benningfield, Kibong Kim The performance enhancement of reactive case materials has been measured for several typical explosive formulations and a number of different case materials. It has been demonstrated that reactive cases can enhance the blast effects of these explosive formulations over that produced using a steel case of equal mass in a well vented confined space testbed. The Defense Threat Reduction Agency (DTRA) has been actively investigating novel energetic materials performance in its Advanced Energetics program and has generated a significant database of cased explosive devices in a two-room, non-responding, vented structure. The testbed and standard test configurations are defined and the reactive case data are compared to the standard steel case designs. [Preview Abstract] |
Monday, June 29, 2009 11:15AM - 11:30AM |
C1.00002: Determination of Explosive Blast Loading Equivalencies with an Explosively Driven Shock Tube Scott Jackson, Larry Hill, John Morris Recently there has been significant interest in evaluating the potential of many different non-ideal energetic materials to cause blast damage. We present a method intended to quantitatively compare the blast loading generated by different energetic materials through use of an explosively driven shock tube. The test explosive is placed at the closed breech end of the tube and initiated with a booster charge. The resulting shock waves are then contained and focused by the tube walls to form a quasi-one-dimensional blast wave. Pressure transducers along the tube wall measure the blast overpressure versus distance from the source and allow the use of the one-dimensional blast scaling relationship to determine the energy deposited into the blast wave per unit mass of test explosive. These values are then compared for different explosives of interest and compared to other methods of equivalency determination. [Preview Abstract] |
Monday, June 29, 2009 11:30AM - 11:45AM |
C1.00003: Internal Blast II: Gas-Mixing Effect in Large Scale (62 cubic meter) Chamber Richard Granholm, Harold Sandusky The previous paper described how incomplete mixing of detonation product gases with the existing atmosphere could theoretically reduce internal blast quasi-static pressure by a factor of two, without considering fuel-air reactions (1). Extent of gas mixing was inferred in small-scale experiments by measuring pressure and temperature at two locations within a 3-liter chamber; unmixed product gases and atmosphere will be hot and cold, respectively. In this paper the study is extended to large scale, with 1 kg pentolite charges in a 62 cubic meter chamber. Fine-wire thermocouples are fast enough for the expanded time scale of events in the larger chamber, about 5 - 10 ms thermocouple response time compared to about 100 ms rise time to peak pressure, and showed significant unmixed regions of gas. Losses in peak quasi-static pressures of up to 11 percent can be attributed to this mixing effect for pentolite charges in the simple geometries tested. --footnote-- (1) Granholm, R.H. and Sandusky, H.W., ``Factors Affecting Internal Blast,'' Shock Compression of Condensed Matter, Proceedings of the 15th A.P.S. Topical Conference on, June 2007. [Preview Abstract] |
Monday, June 29, 2009 11:45AM - 12:00PM |
C1.00004: Momentum and Heat Transfer Models for Detonation in Nitromethane with Metal Particles Robert Ripley, Fan Zhang, Fue-Sang Lien Models for momentum and heat exchange have been derived from the results of previous 3D mesoscale simulations of detonation in packed aluminum particles saturated with nitromethane, where the shock interaction timescale was resolved. In these models, particle acceleration and heating within the shock and detonation zone have been expressed in terms of velocity and temperature transmission factors, which are a function of metal to explosive density ratio, metal volume fraction and ratio of particle size to detonation zone thickness. These models are incorporated as source terms in the governing equations for continuum dense two-phase flow and macroscopic simulation is then applied to detonation of nitromethane/aluminum in lightly-cased cylinders. Heterogeneous detonation features such as velocity deficit, enhanced pressure, and critical diameter effects are reproduced. Various spherical particle diameters from 3 -- 30~$\mu $m are utilized where most of the particles react in the expanding detonation products. Results for detonation velocity, pressure history, failure and U-shaped critical diameter behavior are compared to the existing experiments. [Preview Abstract] |
Monday, June 29, 2009 12:00PM - 12:15PM |
C1.00005: Electromagnetic field effects in explosives Douglas Tasker Present and previous research on the effects of electromagnetic fields on the initiation and detonation of explosives and the electromagnetic properties of explosives are reviewed. Among the topics related to detonating explosives are: measurements of conductivity; enhancement of performance; and control of initiation and growth of reaction. Hayes...()$^{1}$ showed a strong correlation of peak electrical conductivity with carbon content of the detonation products. Ershov.......$^{2}$ linked detailed electrical conductivity measurements with reaction kinetics and this work was extended to enhance detonation performance electrically;...$^{3}$ for this, electrical power densities of the order of 100~TW/m$^{2}$ of explosive surface normal to the detonation front were required. However, small electrical powers are required to affect the initiation and growth of reaction.......$^{4,5}$ A continuation of this work will be reported. {\{}LA-UR 09-00873{\}} .$^{1 }$B. Hayes, \textit{Procs. of 4th Symposium (International) on Detonation} (1965), p. 595. $^{2 }$A. Ershov, P. Zubkov, and L. Luk'yanchikov, Combustion, Explosion, and Shock Waves \textbf{10,} 776-782 (1974). $^{3 }$M. Cowperthwaite, \textit{Procs. 9th Detonation Symposium} (1989), p. 388-395. $^{4 }$M. A. Cook and T. Z. Gwyther, ``Influence of Electric Fields on Shock to Detonation Transition,'' (1965). $^{5 }$D. Salisbury, R. Winter, and L. Biddle, \textit{Procs. of the APS Topical Conference on Shock Compression of Condensed Matter} (2005) p. 1010-1013. [Preview Abstract] |
Monday, June 29, 2009 12:15PM - 12:30PM |
C1.00006: Towards coherent control of energetic material initiation Margo Greenfield, Shawn McGrane, David Moore Direct optical initiation (DOI) of energetic materials using coherent control of localized energy deposition requires understanding how the deposited energy produces a critical size hot spot, which allows propagation of the reaction and thereby initiation. The hot spot characteristics needed for growth to initiation can be studied using thin films of energetic materials. Achieving direct quantum controlled initiation (QCI) in thin film condensed phase systems requires optimally shaped ultrafast laser pulses to coherently guide the energy flow along the desired paths. As a test of our quantum control capabilities we have successfully demonstrated our ability to control the reaction pathway of the chemical system stilbene. An acousto-optical modulator based pulse shaper was used at 266 nm, in a shaped pump / supercontinuum probe technique, to enhance and suppress the relative yields of the cis- to trans-stilbene isomerization. The quantum control techniques tested in the stilbene experiments are currently being used to investigate QCI of thin films and solutions of several different explosives. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700