2.3.13. Fluid-Structure interaction algorithm

SeaFEM features a fluid-structure interaction algorithm, able to perform coupled analysis with the structural solver of the Tdyn’s suite Ramseries. The fluid-structure coupling is performed by an implicit iterative algorithm. This way, the pressure field computed in every iteration of the diffraction-radiation solver is sent to the structural solver to compute the body deformation. The resulting displacements are sent back to the fluid solver, and used as boundary condition to compute the new pressure field for the following iterations. The iterative process continues until the convergence norm condition is fulfilled; the relative distance of the pressure vectors between two successive iterations is below a given value. The iterative algorithm is accelerated using the Aitken method [6]. Since the diffraction-radiation and structural solvers are independent, the strategy used to communicate both solvers is based on the interchange of information at memory level by means of TCP-IP sockets. The library developed for this purpose, also takes care of the data interpolation from one mesh to another mesh.