Greg Gibson and Ian Shields,  University of North Carolina at Chapel Hill

Levitation of Falling Spheres in Variable Density Stratified Fluids

Abstract:  We present  measurements regarding phenomena arising with falling bodies in sharply stratified (two layer) fluids.2   The phenomena in which a heavy falling sphere stops and reverses its motion before ultimate descent to the bottom is further explored through careful adjustment of both the top and the bottom layer fluid density . Specifically, the seemingly disproportionately large changes in flight times due to very slight variations, 10^-5 g/cc, in fluid density are explored.  Additionally, since temperature variation can have such a large impact on density, a large number of data points, over 200, are needed for complete analysis.  An experimental study is presented which documents the bounce amplitude and long layer residence times as functions of the bottom and top layer densities for a 1.04 g/cc density sphere.  This is work by the  RTG FLUID GROUP TEAM: Roberto Camassa, Greg Gipson, Byron Huff, Richard McLaughlin, Richard Parker, Jonathan Toledo University of North Carolina. Funding by RTG NSF DMS-05022662.

Reference:  N. Abaid, D. Adalsteinsson, Akua Agyapong, and R. M. McLaughlin, “An Internal Splash: Falling Spheres in Stratified Fluids,” Physics of Fluids, 16, no. 5, 1567-1580, 2004.


Undergraduate Mentors: Rich McLaughlin and Roberto Camassa (UNC)