(125b) A Parallel Fluid Solid Coupling Model with Lattice Boltzmann Fluid Solver and Molecular Dynamics Simulator Using the Immersed Boundary Method

The study of viscous fluid flow coupled with rigid or deformable solids has many applications in biological and engineering problems, e.g., blood cell transport, drug delivery, and particulate flow. We developed a partitioned approach to solve this coupled Multiphysics problem. The fluid motion was solved by Palabos (Parallel Lattice Boltzmann Solver), while the solid displacement and deformation was simulated by LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). The coupling was achieved through the immersed boundary method (IBM). The code modeled both rigid and deformable solids exposed to flow. The code was validated with the classic problem of rigid ellipsoid particle orbit in shear flow and demonstrated essentially linear scaling over multiple cores. The results showed a 1st order convergence rate. An example of the fluid-solid coupling was given for flexible filaments (drug carriers) transport in a flowing red blood cell suspensions, highlighting the advantages and capabilities of the developed code.