Granular Flow into Model Grain Silos

ORAL

Abstract

It has long been observed that the pressure at the bottom of a granular container, for instance a grain silo, saturates as the height of the container increases relative to its width. However, the precise effect grain shape has on the buildup of sidewall pressure is not well understood. Using a model silo, we investigated the influence of grain shape on sidewall pressure during the filling process. Our silo is 125 cm tall and 16 cm in diameter and is filled with either corn or peas via a cone shaped hopper. This hopper has a lower opening 4 cm in diameter and fills the silo at a constant rate. As the silo fills, we monitor the pressure the grains exert on a 7 cm$^2$ section of the wall. We see that the corn and the peas behave differently. When using the corn, the pressure reaches a peak value and then decays with time. We attribute this decay to the irregular shape of the corn which causes grains higher in the silo to jam and shield the lower grains from the weight above. However, this decay is not as pronounced when using the peas. Since the peas are round, they can more easily rearrange than the irregular corn particles and are not as effective at screening the pressure.

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Authors

  • Eli Owens

    Presbyterian College

  • Brad Cox

    North Carolnia State University, Vanderbilt University, University of South Carolina, University of Virginia, Francis Marion Univ, Oak Ridge National Laboratory, Massachusetts Institute of Technology, Florida International University, Georgia College, JINR, Tsinghua University, LBNL, GANIL, Austin Peay State University, Lehigh University, University of Pardubice, Universit\'e de Rennes, Austin Peay State University Department of Physics and Astronomy, Oak Ridge National Laboratory, Oak Ridge TN 37831, American Superconductor Corp., Westborough MA 01581, University of North Georgia, Dahlonega GA 30597, Florida State University, Ecole Polytechnique, Space Telescope Science Institute, Fermi National Accelerator Lab, National Optical Astronomy Observatory, Austin Peay State Univerity, North Carolna State University, Florida Intl Univ, University of North Georgia, Clemson University, Clemson Univ, Vanderbilt University/ORNL, Vanderbilt University/Univ. of Kentucky, College of William and Mary, Louisiana State University, Presbyterian College, North Carolina State Univ, Department of Physics, Virginia Tech, Mathematical Institute, University of Oxford, Virginia Tech University, Hollins University, University of Tennessee Space Institute, Davidson College, University of Tennessee, American Superconductor Corporation, University of South Alabama, North Carolina State University, James Madison University, Lousiana State University, Korea Electrotechnology Research Institute, Changwon Korea