Development of parallel DEM for the open source code MFIX

The paper presents the development of a parallel Discrete Element Method (DEM) solver for the open source code, Multiphase Flow with Interphase eXchange (MFIX) based on the domain decomposition method. The performance of the code was evaluated by simulating a bubbling fluidized bed with 2.5 million particles. The DEM solver shows strong scalability up to 256 processors with an efficiency of 81%. Further, to analyze weak scaling, the static height of the fluidized bed was increased to hold 5 and 10 million particles. The results show that global communication cost increases with problem size while the computational cost remains constant. Further, the effects of static bed height on the bubble hydrodynamics and mixing characteristics are analyzed.

An efficient parallel algorithm for DEM using the domain decomposition method is developed for MFIX. A scaling analysis is carried out for a fluidized bed with 2.56 million particles. The figures show the speedup and efficiency of the DEM solver, flow solver and full simulation. For a 256 processor, the DEM solver results in a speed of up to 208 at 81% efficiency.Figure optionsDownload as PowerPoint slideHighlights
► We developed parallel DEM for the open source code MFIX.
► Scaling analysis show strong scaling up to 256 processors for DEM.
► A speedup of 208 is obtained for DEM solver at an efficiency of 81%.
► Weak scaling shows that global communication affects performance of large systems.
► Increasing bed height for low superficial velocity results in slug flow.