Dynamics of a bouncing dimer

S. Dorbolo, D. Volfson, L. Tsimring, and A. Kudrolli

Phys. Rev. Lett. 95, 044101 (2005)

Abstract: We investigate the dynamics of a dimer bouncing on a vertically oscillated plate. The dimer, composed of two spheres rigidly connected by a light rod, exhibits several modes depending on initial and driving conditions. The first excited mode has a novel horizontal drift in which one end of the dimer stays on the plate during most of the cycle, while the other end bounces in phase with the plate. The speed and direction of the drift depend on the aspect ratio of the dimer. We employ event-driven simulations based on a detailed treatment of frictional interactions between the dimer and the plate in order to elucidate the nature of the transport mechanism in the drift mode.

A movie of the drift mode


sphere diameter = 9.5 mm, A_r = 3.9, Gamma = 0.9, f = 25 Hz

Examples of the lowest three excited modes observed:

Drift mode

Jump mode

Flutter mode


A movie of the drift mode observed on an oscillated two dimensional flat surface.
Here, a wire is wrapped around the center of the dimer to prevent it from rolling about its axis of symmetry.

Contact:
Arshad Kudrolli
akudrolli@clarku.edu
Date: September 28, 2004