Porosity Calculation in Discrete Element Modeling of Sand Cutting Process
Type:
Presented during:
WODCON XX: "The Art of Dredging" - 2013, Brussels, Belgium
Authors:
Chen X, Miedema SA
Abstract: To calculate the pore pressure in the sand cutting simulation based on discrete element modeling (DEM), the key is to track the porosity change in the sand specimen during the cutting process. In this paper a numerical method is described to track the porosity change in the sand cutting process which uses a blade. The simulation is conducted in 3D by EDEMTM, a software package based on DEM.
First several different geometries are tested in the simulation to imitate the natural shape of sand particles. It is found that some of the particle shapes will greatly influence the macro behavior of the sand specimen, and correspondingly the cutting force records on the blade can be different from each other. To track the porosity change, the simulation zone is organized by a grid system, where all the grid cells are cubes with identical volume. At every time step, the position information of the blade and particles is transferred to the porosity calculation module, then the porosity of each grid cell is calculated and thus the porosity change can be tracked.
It is concluded that the calculation of porosity change in the 3D DEM simulation can give an acceptable result. However, the disadvantage is that the accuracy of the calculation may not be fully reached due to the approximations in the volume calculation. The next step will be applying the water pore pressure calculation to improve the simulation from dry environment into water saturated environment, meanwhile conducting the coupling between DEM software and computational fluid dynamics (CFD) software.
This paper will show the detailed methodology and results of the simulation and calculation.
Keywords: porosity, sand, DEM, simulation