Sánchez P, Swift Michael R, King P J
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2004 Oct 29;93(18):184302. doi: 10.1103/PhysRevLett.93.184302. Epub 2004 Oct 28.
We describe an investigation of fluid-immersed granular mixtures subjected to horizontal vibration. For sufficiently large amplitudes of vibration, a mixture of equal-sized glass and bronze particles in water is found to separate into a striped pattern. Numerical simulations based on soft-sphere molecular dynamics coupled to the interstitial fluid are able to capture many of the features observed experimentally. We propose a general pattern-formation mechanism based on the differential influence of drag on the components of the mixture. An expression for the number of stripes as a function of the system parameters is derived and shown to be in good agreement with experiments.
