Bulletin of the American Physical Society
20th Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matter
Volume 62, Number 9
Sunday–Friday, July 9–14, 2017; St. Louis, Missouri
Session P6: Focus Session: Ejecta Physics IV |
Hide Abstracts |
Chair: Martin Schauer, Los Alamos National Laboratory Room: Regency Ballroom E |
Wednesday, July 12, 2017 11:15AM - 11:30AM |
P6.00001: Mesoscale Computations of Shock-Particle Interaction In Near-Wall Proximity Fady Najjar Understanding shock-particle interactions is fundamental for a variety of physics and engineering problems. Particle response to the shock-induced flow acceleration results in a large uncertainty, hindering the computational capability to predict such complex flow. The key parameters are the forces on the particle, its motion and speed. These effects are further complicated when the particles are in the proximity of the wall and a shock interacts with them. We will present results from 3D hydrodynamics simulations performed to study the interaction of shock waves with metal particles under various shock loading conditions. Initial validation study is performed for shock-particle interaction. The particle’s speed and its motion, as well the generated drag and lift forces, will be calculated. Such computations will provide important inputs to develop advanced drag and lift models for relevant multiphase flows. [Preview Abstract] |
Wednesday, July 12, 2017 11:30AM - 11:45AM |
P6.00002: PDV-based estimation of high-speed ejecta particles density from shock-loaded tin plate Jean-Eloi Franzkowiak, Gabriel Prudhomme, Patrick Mercier, Séverine Lauriot, Estelle Dubreuil, Laurent Berthe A machine-grooved metallic tin surface is explosively driven by a detonator with a shock-induced pressure of 25 GPa. The resulting dynamic fragmentation process called micro-jetting is the creation of high-speed jets of matter moving faster than the bulk metallic surface. The resulting fragmentation into micron-sized metallic particles generates a self-expanding cloud of droplets, whose areal mass, velocity and size distributions are unknown. Lithium-Niobate (LN) piezoelectric pin measured areal mass and Photonic Doppler Velocimetry (PDV) was employed to get a time-velocity spectrogram of the cloud. We present both experimental mass and velocity results and relate the integrated areal mass of the cloud to the PDV power spectral density under the assumption of a power law distribution for particle sizes. A model of PDV spectrograms is described, for which speckle fluctuations are averaged out. Finally, we use our model for a Maximum Likelihood Estimation of the cloud's parameters from PDV data. The integrated areal mass deduced from the PDV analysis is in good agreement with piezoelectric results. We underline the relevance of analyzing PDV data and correlating different diagnostics to retrieve the macro-physical properties of ejecta particles. [Preview Abstract] |
Wednesday, July 12, 2017 11:45AM - 12:00PM |
P6.00003: Study of registration threshold for minimal specific weight of particles when investigating shock-wave ejection from material surface using laser heterodyne-interferometer. Recording of multiple doppler frequency shift effect. Alexey Fedorov, Anatoly Mikhailov, Stanislav Finyushin, Ev'geniy Chudakov, Denis Kalashnikov, Ev'geniy Butusov, Ivan Gnutov When the shock wave reaches the free metal surface, the particle ejection occurs. Particle flow parameters are recorded by different methods. This paper contains the results of experimental series on determination of minimal specific weight of the particle flow, when particle velocities can be recorded using laser heterodyne-interferometer (PDV method). The registration threshold is determined by measuring the velocity of ejected particles after coating a test surface with a layer of particles having the certain specific weight. The effect of laser emission interaction with a thin layer of particles is recorded in experiments, and it causes the multiple Doppler frequency shift. This effect plays a vital role in interpretation of data obtained in experiments with recording of parameters of shock loaded ejection of materials. [Preview Abstract] |
Wednesday, July 12, 2017 12:00PM - 12:15PM |
P6.00004: Photon Doppler velocimetry of ejecta from shock-loaded samples Arseniy Kondratyev, A. Andriyash, S. Kuratov, D. Rogozkin, M. Astashkin, V. Baranov, A. Golubinskii, D. Irinichev, V. Mazanov, S. Stepushkin, V. Khatunkin The report addresses the problem of recovering the ejecta parameters from PDV data. The results of PDV-measurements of ejecta production from shock-loaded Pb samples are presented. Shockwaves were generated by a flyer-plate accelerated up to 3 km/s. Depending on the sample thickness, the shock-breakout pressure varied from 23 to 45 GPa. The ejecta transport occurred in air. Spectral profile $E(\omega)$ of heterodyne beats underlies our analysis of the experiments. Under the assumption that ejected particles are disordered, the profile square $\vert E(\omega)\vert^2$ is subject to the transport equation which accounts for multiple scattering and absorption of the probing beam in the ejecta cloud. We solve the transport equation with the discrete-ordinate code. Adjusting the free surface velocity, the optical thickness and the parameters of the velocity distribution of the ejecta scattering coefficient, we gain a good fit of the calculated profile to the PDV-measured one. Such an approach enables us, based on the ejecta optical model, to recover the areal density and the density-velocity distribution from PDV data, e.g., to determine how this distribution changes in time due to the particle slowing-down in air. [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