Nonlinear Sound Propagation in Granular Media (SOUND)
research area: materials sciences
Nonlinear Sound Propagation in Granular Media
experiment acronym: SOUND
funding agency: ESA
grant number: ESA - Program
DLR - Institute for Materials Physics in Space, Cologne, Germany /
Institut Langevin, ESPCI, Paris, France
Prof. Dr. Andreas Meyer, Prof. Dr. Matthias Sperl, Dr. Peidong Yu /
Prof. Xiaoping Jia, Dr. Siet van den Wildenberg
Sound propagation in granular systems is a complex wave phenomena (e.g., multiple sound scattering, nonlinear acoustics), but also it may be used as a non-invasive tool to probe the packing structure and the mechanical properties [1-2]. Under weak compression and relatively strong excitation, the nonlinear nature of particle interaction becomes very important and is reflected by a transition of the propagation regime. Numerical simulation showed that the wave speed increases with the excitation amplitude according to a power law dependence . This dependence is a trademark of the soliton-like shock wave in the highly nonlinear regime and was later partially verified by ground experiments . The current limitation of such experiments is that the weight of the particles always causes some compression of the system, and a marginal or unjammed state proposed in  can not be reached for three-dimensional systems. Low gravity condition in this case becomes essential to realize this highly nonlinear regime. Therefore we propose building a nonlinear sound excitation and detection setup for low gravity facilities to fully investigate the wave speed and the dissipation under close-to-zero compression.
-  C. Liu and S. R. Nagel, "Sound in sand", Phys. Rev. Lett., vol. 68, pp. 2301-2304, Apr. 1992.
-  X. Jia, C. Caroli, and B. Velicky, "Ultrasound propagation in externally stressed granular media", Phy. Rev. Lett., vol. 82, pp. 1863-1866, Mar. 1999.
-  L. R. Gomez, A. M. Turner, M. van Hecke, and V. Vitelli, "Shocks near Jamming", Phys. Rev. Lett., vol. 108, pp. 058001, Jan. 2012.
-  S. van den Wildenberg, R. van Loo, and M. van Hecke, "Shock waves in weakly compressed granular media", Phys. Rev. Lett. 111, 218003, Nov. 2013
experiment year: 2017
number of catapult launches: 10
experiment year: 2015
number of catapult launches: 2
number of drops: 6
experiment year: 2014
number of catapult launches: 8