Large-scale parallel simulation of fluid-structure interaction based on immersed-boundary method

A three-dimensional parallel simulation tool of the fluid-structure interaction (FSI) using a direct-forcing immersed-boundary method is presented. The computational framework is based on a partitioned approach and can handle a range of biological FSI problems involving large deformations. We have implemented an efficient parallel strategy based on a simple idea of domain decomposition. For the flow, the computational domain is decomposed into subdomains in either 1D, 2D, or 3D, thus allowing the use tens of thousands of processors for parallel computing. The immersed-boundary treatment, including identification of the IBLANK (i.e., determination of the fluid and solid nodes on the grid) and direct forcing, is done within each subdomain and is well scaled like the other parts of the solution process for the numerical PDE. Furthermore, the total memory allocation is nearly constant regardless the number of processors. These features allow simulations using a mesh size of one billion points. We will demonstrate applications in several problems, including glottal airflow/vocal fold, heart valve, and animal flight.