A coupled Discrete Element Lattice Boltzmann Method for the simulation of fluid–solid interaction with particles of general shapes

In the present paper a coupling law between the Lattice Boltzmann Method (LBM) for fluids and the Discrete Element Method (DEM) is introduced to study problems involving the interaction between fluids and solid (rigid) structures. The DEM particles are modelled with the sphero–polyhedra method, allowing the representation of general shapes, even non-convex ones. The method is rigorously validated by an extensive simulation plan measuring the lift and drag coefficients for several geometries and comparing the results with previous studies. The method also includes some optimization techniques which are described in the paper. Finally, simulations of DEM particles with shapes of animals (dolphins and ducks) are carried out interacting with multiphase and multicomponent LBM fluids, and many realistic features of this interaction such as buoyancy, sonic wave propagation and fluid displacement are shown to qualitatively match observations. Some issues with the coupling law are identified for future research studies on the proposed method. The results show the potential of the method to be used in the simulation of a wide range of phenomena found in sectors such as the mining and oil industries and disciplines such as medicine and biology.