Mohamed Chekired

3D Numerical Simulations of Particle–Water Interaction Using a Virtual Approach

Three-dimensional flow of a Newtonian fluid through porous media consisting of multisized perfectly spherical beads is numerically simulated. Porous media are virtually and randomly generated, in accordance with the particle size distribution. All the physical features of the porous media are fully represented and considered, in order to closely mimic the heterogeneity of these media. Simulations show that the smallest particles strongly affect the streamline shape by imposing small pores and small throats, and also by providing the shortest paths. The third dimension has a particular effect, which is to allow the streamlines to follow the path of least resistance, where the least amount of energy is required to produce the motion of a fluid particle. Once the three-dimensional images have been produced, the proposed model provides a three-dimensional representation of the streamlines and their velocity. Unfortunately, the results currently generated do not agree well with those proposed in the literature. Consequently, there is a pressing need to verify these results by conducting more numerical tests.

A MORE COMPREHENSIVE MODELING OF CONTACT FORCE DURING SHEAR TESTING USING DEM

Abstract. The subject of this paper is a visualization tool which may prove helpful for understanding the highly complex responses of granular systems during shear tests. The motivation of such approach is to face the challenge related to the micro scale contact forces in a granular system. The Discrete Element Method (DEM) was used to simulate shear testing on an assembly of spherical glass beads. All simulations were performed using the 3D virtual laboratory SiGran. The macro-scale response of the granular system is presented, including energy and force distributions. Two particle-size distributions were considered in the study to validate the virtual approach. The influence of the contact model is also a part of this study.