A study on the influence of particle shape on the mechanical interactions of granular media in a hopper using the Discrete Element Method

• Increase of shear strength with decreasing sphericity or increasing aspect ratio.
• Good DEM predictions of the hopper discharge properties.
• Minor influence of approximation scheme used in DEM on simulation results.

In this study experimental and numerical investigations with the Discrete Element Method (DEM) on the mechanical interactions of particles with varying sphericity and aspect ratio in a rectangular hopper are conducted. In the DEM the test particles are approximated by four commonly used approximation schemes.A decrease of particle sphericity or an increase of the aspect ratio results in an more uneven, intermittend particle flow and overall lower discharge rate. It was deducted from the measurement results that changing these geometric particle properties elevates the shear strength of the particle bed and, hence, has a significant influence on the discharge properties of a hopper.Simulation results are in good general agreement with the experiments and thus demonstrate the adequacy of the DEM to predict the mechanical interactions in granular media consisting of non-spherical particles. The results presented in this study show only a minor influence of the method used to approximate particle shape within the DEM. Obviously the discharge characteristics are much stronger related to macroscopic geometric parameters than the fine scale resolution of particle geometry.

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