Date of Award
9-2011
Document type
dissertation
Access Type
Open Access Dissertation
Degree Name
Doctor of Philosophy (PhD)
Degree Program
Physics
First Advisor
Donald Candela
Second Advisor
Narayanan Menon
Third Advisor
Anthony Dinsmore
Subject Categories
Physics
Abstract
This dissertation presents experiments that studied two gravity driven granular channel flows. The first experiment used magnetic resonance imaging to measure the density and displacement distributions of poppy seeds flowing in a rough walled channel. Time-averaged measurements of normalized velocity and density showed little flow speed dependence. Instantaneous measurements, however, showed marked velocity dependence in the displacement distributions. There was evidence of aperiodic starting and stopping at lower flow speeds and the onset of density waves on a continuous flow at higher speeds. The second experiment measured forces in all three spatial directions at the boundary of a flow of steel balls. The relationship between the normal and the tangential forces were examined statistically and compared to the Coulomb friction model. For both large and small forces, the tangential and normal forces are unrelated, as there appears to be a strong tendency for the tangential force to maintain a value that will bear the weight the weight of the particles in flow.
DOI
https://doi.org/10.7275/2387762
Recommended Citation
Facto, Kevin, "Measurements of Gravity Driven Granular Channel Flows" (2011). Open Access Dissertations. 462.
https://doi.org/10.7275/2387762
https://scholarworks.umass.edu/open_access_dissertations/462