Concurrent DEM Simulations at Multiple Levels of Detail
Sprache des Vortragstitels:
14th Minisymposium Chemical and Process Engineering and 5th Austrian Particle Forum
Sprache des Tagungstitel:
Since its introduction by Cundall and Strack, the discrete element method (DEM) has proven to be a viable tool for the analysis of granular systems. In a broad range of industrial sectors, DEM simulations are used for process evaluation and optimization. However, a major shortcoming of the DEM is its high demand for computational resources, due to the tracking of each individual particle.
A coarse-graining (CG) model of the DEM has been introduced by Bierwisch et al. to reduce the hardware requirements. The CG model replaces multiple equal particles by one coarser pseudo-particle, thus effectively decreasing the number of particles in the simulation. A dimensional analysis of the contact laws requires that upon upscaling the particles the contact forces need to be modified to keep the energy density consistent.
Despite this adaption, the CG model comes with a serious deficit: upscaling the particles while keeping boundaries in the system unchanged violates the geometric similarity. Consequently, the CG model may fail to correctly predict the system behavior. The deviation from the original system rises as the scaling factor is increased and the size of the pseudo-particles gets comparable to geometrical features.
To improve this situation we propose a new technique to concurrently simulate granular flows at different coarse-grain levels, where spatially confined subdomains of finer scale are embedded into coarser representations of the system. Following this approach allows capturing the details of the granular system in regions of interest while retaining the computational benefits of the CG model where a lower resolution is sufficient.