Theoretical validation of a multi-sphere discrete element model suitable for biomaterials handling simulation

Application of the discrete element method for real agricultural particulate materials involves some common phenomenon such as friction, sliding, handling, rotation, and particle collision. The validity of the multisphere method (MSM) was examined analytically for these phenomena by comparing the prediction of the discrete element (DE) model using multi-sphere particles with the results of analytical calculations of the movement of particles in different situations. In the simulations, the particles were smooth with a round but non-spherical surface which is close to the geometrical characteristics of some real agricultural particles. The analytical validation of the model confirmed that this method could handle different operations such as sliding, dropping and conveying of systems comprising non-spherical particles with high-aspect ratio. Although analytical validation provided evidence that the DE model based on the multi-sphere method was properly formulated, it could not demonstrate that the MSM could be used to predict the dynamic behaviour of a physical model with specific physical properties. Some experimental validations are also needed to evaluate this aspect of the MSM discrete element model. (C) 2004 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.