A highly extensible smoothed particle hydrodynamics with meshless fluid-end general interpolation method based on precise code interaction coupling environment for fluid–structure interaction surface coupling

Solving fluid–structure interaction (FSI) problems using traditional methods poses significant challenges in the field of numerical simulation. The multiphysics coupling library precise code interaction coupling environment (preCICE), renowned for its robust multiphysics coupling capabilities, offers a promising solution for FSI problems. It supports various open/closed source software and commercial computational fluid dynamics solvers in a black box manner. However, preCICE currently mainly supports coupling schemes of mesh-based methods as well as few meshless methods. This paper proposes a critical grid interpolation (CGI) method as an intermediate medium to enable the particle method to interface with preCICE. The CGI method leverages particles and critical meshes to interpolate displacement and force, thereby allowing the pure Lagrangian smoothed particle hydrodynamics (SPH) method to solve FSI problems. The critical mesh serves as a coupling interface between particles and meshes, theoretically resolving the mesh mismatch issue inherent in particle methods when connecting to preCICE. To validate the performance of the proposed CGI method, we conducted experiments where the fluid and the structure were discretized using SPH and the finite element method, respectively. The results demonstrate the effectiveness of the CGI method in solving FSI problems. Additionally, we have made our source code for the SPH fluid adapter open-source and available on (https://github.com/terrylongsifan/AdapterSPH), facilitating further development of preCICE compatibility with more meshless methods. This study significantly advances the application of SPH in FSI problems by integrating it with preCICE, thereby expanding the versatility and applicability of multiphysics simulations.