Particle sedimentation using hybrid Lattice Boltzmann-immersed boundary method scheme

Abstract Particle collisions play a critical role in determining the fluid-particle interaction. Thus, particulate matters and their interaction within a flow need an accurate treatment through felicitous composite methods. Accordingly, we present a numerical simulation based on a combined Lattice Boltzmann Method (LBM), Immersed Boundary Method (IBM), and Hard Sphere Molecular Dynamics (HSMD) scheme, with applications. This simulation method aims to understand spherical point-particle sedimentation in an incompressible Newtonian fluid. A Stokes' drag model implements the hydrodynamic interaction using Ladd's LBM scheme and a momentum exchange based IBM. The HSMD evaluates the discrete particles' kinematics and trajectory. We simulate a 3D single particle settling case as a benchmark. The simulation result exhibits a close match between the terminal particle velocity and an analytical result; it reproduces the expected exponential behavior. Finally, a sedimentation case involving 7200 particles demonstrates the composite schemes' capability to solve the complex interactions. This article discusses the interesting observations and results.