ABSTRACT

A single large intruder that is initially embedded at the bottom of a vertically vibrated, quasi two-dimensional rectangular cell packed with small seeds always rises to the top. For a range of relative density ratios, cell widths, heights and intruder sizes, we find that the intruder rise time τ, measured at several sinusoidal vibration frequencies f and peak-to-peak amplitudes a, varies as τ ~ (aω-vc)-β where = 2f, vc can be identified as the critical vibration velocity for the onset of convective motion of the small seeds and β depends on the width of the cell. These experiments demonstrate that in boundary-driven granular convection experiments such as ours, the peak-to-peak velocity of shaking, rather than the peak to peak acceleration, is the relevant parameter for describing the results.

ABOUT THE SPEAKER

Dr. Ranjini Bandyopadhyay did her Ph.D. from IISc Bangalore in Physics in 2001. Subsequently she joined University of California Los Angelis as a postdoctoral fellow for two years. She did her second post doc at John Hopkins University before joining Raman Research Institute in 2005. She is presently an Associate Professor in RRI. He research interests include various problems in Soft Condensed Matter Physics.