Solving Fluid-Structure Interaction (FSI) problems using traditional methods is a big challenge in the field of numerical simulation. As a powerful multi-physical field coupled library, preCICE has a bright application prospect for solving FSI, which supports many open/closed source software and commercial CFD solvers to solve FSI problems in the form of a black box. However, this library currently only supports mesh-based coupling schemes. This paper proposes a critical grid (mesh) as an intermediate medium for the particle method to connect a bidirectional coupling tool named preCICE. The particle and critical mesh are used to interpolate the displacement and force so that the pure Lagrangian Smoothed Particle Hydrodynamic (SPH) method can also solve the FSI problem. This method is called the particle mesh coupling (PMC) method, which theoretically solves the mesh mismatch problem based on the particle method to connect preCICE. In addition, we conduct experiments to verify the performance of the PMC method, in which the fluid and the structure is discretized by SPH and the Finite Element Method (FEM), respectively. The results show that the PMC method given in this paper is effective for solving FSI problems. Finally, our source code for the SPH fluid adapter is open-source and available on GitHub for further developing preCICE compatibility with more meshless methods.

翻译：采用传统方法解决流固耦合（FSI）问题是数值模拟领域的重大挑战。作为强大的多物理场耦合库，preCICE在求解FSI方面具有广阔应用前景，支持以黑箱形式集成多种开源/商业CFD求解器与闭源软件。然而，该库目前仅支持基于网格的耦合方案。本文提出以临界网格（mesh）作为中间介质，使粒子方法能够连接名为preCICE的双向耦合工具。通过粒子与临界网格对位移和力进行插值，使得纯拉格朗日光滑粒子流体动力学（SPH）方法也能求解FSI问题。该方法被称为粒子-网格耦合（PMC）方法，理论上解决了基于粒子方法连接preCICE时的网格不匹配问题。此外，我们通过实验验证PMC方法的性能，其中流体与结构分别采用SPH和有限元法（FEM）离散。结果表明，本文提出的PMC方法能有效求解FSI问题。最后，我们的SPH流体适配器源代码已在GitHub上开源，可用于进一步扩展preCICE对更多无网格方法的兼容性。