Bulletin of the American Physical Society
18th Biennial Intl. Conference of the APS Topical Group on Shock Compression of Condensed Matter held in conjunction with the 24th Biennial Intl. Conference of the Intl. Association for the Advancement of High Pressure Science and Technology (AIRAPT)
Volume 58, Number 7
Sunday–Friday, July 7–12, 2013; Seattle, Washington
Session J3: NT.1 Novel Techniques: Gun capabilities/Shock tubes |
Hide Abstracts |
Chair: William Buttler, Los Alamos National Laboratory Room: Fifth Avenue |
Tuesday, July 9, 2013 11:00AM - 11:15AM |
J3.00001: Methods of Controlled Shock Wave Generation in A Shock Tube for Biological Applications Thuy-Tien Nguyen, James Wilgeroth, Warren Macdonald, William Proud The shock tube is a versatile yet simple equipment used in a wide range of scientific research. The diaphragm breakage process, manipulated by different operation methods, is closely linked to the shock wave generated. Experiments were performed on a compressed air-driven shock tube with mylar and aluminium diaphragms of various thicknesses to characterise the output. The evolution of the pressure generated was measured and the diaphragm rupture investigated. Single-diaphragm and double-diaphragm configurations were employed, as were open or closed tube configurations. The arrangement was designed to enable high-speed photography and pressure measurements. Overall, results are highly reproducible, and show that the double-diaphragm system enables a more controllable diaphragm burst pressure. The diaphragm burst pressure was linearly related to its thickness within the range studied. The observed relationship between the diaphragm burst pressure and the generated shock pressure presents a noticeable difference compared to the theoretical ideal gas description. Furthermore, the duration of the primary shock decreased with the volume of the high-pressure charging gas. Computational modelling of the diaphragm breakage process was carried out using the ANSYS software package. [Preview Abstract] |
Tuesday, July 9, 2013 11:15AM - 11:30AM |
J3.00002: Experiments on a Miniature Hypervelocity Shock Tube Douglas Tasker, Carl Johnson, Michael Murphy, Mark Lieber A miniature explosively-driven shock tube, based on the Voitenko compressor design [1], has been designed to produce shock speeds in light gases in excess of 80 km/s. Voitenko compressors over 1 meter in diameter have been reported but here experiments on miniature shock tubes with $\sim$1-mm bore diameters are described. In this design a 12-mm diameter explosive pellet drives a metal plate into a hemispherical gas compression chamber. Downstream from the piston a mica diaphragm separates the gas from an evacuated shock tube which is confined by a massive polymethylmethacrylate (PMMA) block. The diaphragm eventually ruptures under the applied pressure loading and the compressed gases escape into the evacuated shock tube at hyper velocities. The progress of gas shocks in the tube and bow shocks in the PMMA are monitored with an ultra-high-speed imaging system, the Shock Wave Image Framing Technique (SWIFT) [2]. The resulting time-resolved images yield two-dimensional visualizations of shock geometry and progression. By measuring both the gas and bow shocks, accurate and unequivocal measurements of shock position history are obtained. The experimental results were compared with those of hydrocode modeling to optimize the design. The first experiments were suboptimum in that the velocities were $\sim$16 km/s. Progress with these experiments will be reported.\\[4pt] [1] A. E. Voitenko, Dokl. Akad. Nauk SSSR 158 (6), 1278-1280 (1964).\\[0pt] [2] M. J. Murphy and S. A. Clarke, in Dynamic Behavior of Materials, Volume 1, (2013), pp. 425-432. [Preview Abstract] |
Tuesday, July 9, 2013 11:30AM - 11:45AM |
J3.00003: Non-Invasive Timing of Gas Gun Projectiles with Light Detection and Ranging Peter Goodwin, Ming Wu, Dana Dattelbaum We have developed a \underline {Li}ght \underline {D}etection \underline {a}nd \underline {R}anging (LIDAR) diagnostic to track the position of a projectile inside of the gas gun barrel in real-time. This capability permits the generation of precisely timed trigger pulses useful for pre-triggering high-latency diagnostics such as a flash lamp-pumped laser. An initial feasibility test was performed using a 72 mm bore single-stage gas gun routinely used for dynamic research at Los Alamos National Laboratory. A 655-nm pulsed ($\sim$ 100 ps) diode laser operating at a pulse repetition rate of $\sim$100 kHz was used to interrogate the position of the moving projectile in real-time. The position of the projectile in the gun barrel was tracked over a distance of $\sim$3 meters prior to impact. The position record showed that the projectile moved at a constant velocity (483 m/s) prior to impacting the target. This velocity was in good agreement with independent measurements of the projectile velocity by photon Doppler velocimetry, and timing of the passage of the projectile through optical marker beams positioned at the muzzle of the gun. The LIDAR return can be processed in real-time to generate pre-trigger pulses at preset separations between the projectile and target. [Preview Abstract] |
Tuesday, July 9, 2013 11:45AM - 12:00PM |
J3.00004: Sample Preheating Capability for Dynamic Material Studies*$^{+}$ J.L. Wise, D.G. Dalton, R.J. Hickman, M.I. Kaufman, S.A. Leffler, M.J. Jones, J.J. Lynch, A.C. Bowers Coordinated analysis, design, software development, hardware fabrication, and testing activities have yielded a new control system and experimental load design for dynamic material studies on specimens heated to temperatures exceeding 650$^{\circ}$C prior to high-rate compression on a pulsed-power (e.g., Z machine) or gun platform. A proportional integral derivative controller supplies power for up to 16 resistive cartridge heaters mounted in a load assembly containing one or more test samples. The electrical output from this LabVIEW-based controller to each heater is continuously adjusted using feedback from thermocouples embedded in the load and in each heater. Experiments confirm steady temperature regulation to within $+$/-2$^{\circ}$C of the selected set point, as well as adequate surge protection from built-in electromagnetic pulse isolation circuitry. ANSYS thermomechanical simulations have guided the refinement of load design to minimize sample temperature gradients and thermal distortion. Improved thin-film coatings for the sample/window interface are being developed to ensure the viability of velocity interferometry measurements on preheated samples. *Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000; $^{+}$This work was done by National Security Technologies, LLC, under Contract DE-AC52-06NA25946 with the U.S. Department of Energy. [Preview Abstract] |
Tuesday, July 9, 2013 12:00PM - 12:15PM |
J3.00005: Use of synchrotron radiation for research of flow of a products of detonation Lev Merzhievsky, E.R. Pruuel, K.A. Ten, V.M. Titov, L.A. Luk'yanchikov, E.B. Smirnov, A.K. Muzirya Results of studying detonation processes in condensed high explosives, which are obtained by methods based on using synchrotron radiation, are given. Data on the density distribution in the detonation front and behind the front for several high explosives are presented. Spatial distribution of density of products of a detonation, and values of parameters in the Neumann spike and at the Jouguet point are determined. A method of reconstruction of the distributions of gasdynamic characteristics of the flow of products of a detonation (density fields, particle velocity vector, and pressure) in the space was proposed and tested. Results of using this method for studying detonation of a charge of TNT and plasticbonded TATB are presented. The obtained data are a basis for determination of parameters of the equations of state of products of a detonation. [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