The effect of particle shape on porosity of swelling granular materials: Discrete element method and the multi-sphere approximation

摘要

The porosity value of swelling granular materials depends on the degree of swelling and the state-of-stress inside the packing. This research focusses on the swelling of a bed of Super Absorbent Polymer (SAP) particles, which are absorbent particles that can absorb 30 to 40 times their initial weight of saline fluids. Due to the complexity of swelling materials, measurements of porosity, and also hydraulic parameters, are complex and often not feasible, unless a quasi-static approach is employed. An alternative is not only to conduct measurements, but in addition to generate artificial packings using a grain-scale model from which porosity values can be derived. The combination of experiments and simulations reduce the experimental efforts whilst allowing for an understanding of particle-scale phenomena.