Application of Discrete Element Method Simulation in Environmental Modeling

Abstract

The compaction of arable soil, on the one hand, changes the geometry of the soil pores and reduces cavities between soil particles, consequently reducing the ability to retain fluids in these pores. On the other hand, the compaction alters the soil constituents, which has a negative effect on the soil ecological efficiency. Although many efforts have been made to gain a deep and quantitative understanding of the stress transfer and deformation process in arable soils, using a realistic approach can better predict the effects of soil management, such as those from farmland traffic on soil yield. One way to obtain information about the behavior of granular media is to perform simulations with the discrete element method (DEM), which provides the opportunity to track the motion of every single particle in the soil, and as a consequence, it can discern how microstructures affect the macroscopic properties of the soil. In fact, DEM modeling is a virtual laboratory in which the physical and mechanical behavior of granular materials can be predicted with respect to their smaller components. It would be difficult to investigate the effects of these smaller components with other experimental methods. In this chapter, the fundamentals of DEM are reviewed, and two applications of this method for modeling of soil compaction in agricultural field traffic are presented, along with a discussion of the results. The ability to visualize the results of DEM modeling is a great advantage, compared with experimental methods that require high-tech devices, such as X-rays and high-resolution cameras.