论文标题
用于流体结构相互作用的新型平滑粒子流体动力学和有限元耦合方案:滑动边界粒子方法
A novel smoothed particle hydrodynamics and finite element coupling scheme for fluid-structure interaction: the sliding boundary particle approach
论文作者
论文摘要
提出了一种用于解决流体结构相互作用(FSI)问题的新型数值公式,其中使用有限元方法(FEM)使用平滑的粒子流体动力学(SPH)和结构场进行空间离散的流体场。与完全基于网格或网格的FSI框架相比,由于SPH的拉格朗日性质,该框架可以很容易地扩展,以说明由多个阶段和动态相变组成的更复杂的流体。此外,这种方法分别促进了流体结构界面的大型变形,而无需其他方法论和计算工作。特别是,为了实现流体颗粒与结构元素之间的相互作用力的准确表示,也为强弯曲的界面几何形状而言,提出了新型的滑动边界粒子方法,以确保对接近界面的SPH颗粒的全面支撑。流体和结构场的耦合是基于Dirichlet-Neumann分区方法,其中流体场是带有规定的界面位移的Dirichlet分区,结构场是neumann分区,属于界面力。为了克服弱耦合方案固有的不稳定性,采用了迭代的固定点耦合方案。以众所周知的基准测试形式的几个数值示例被认为是验证所提出的公式的准确性,稳定性和鲁棒性。最后,研究了一个高度柔韧性的薄壁样品容器的填充过程,代表了一个模型问题,即生物力学领域所提出的方案的潜在应用方案。
A novel numerical formulation for solving fluid-structure interaction (FSI) problems is proposed where the fluid field is spatially discretized using smoothed particle hydrodynamics (SPH) and the structural field using the finite element method (FEM). As compared to fully mesh- or grid-based FSI frameworks, due to the Lagrangian nature of SPH this framework can be easily extended to account for more complex fluids consisting of multiple phases and dynamic phase transitions. Moreover, this approach facilitates the handling of large deformations of the fluid domain respectively the fluid-structure interface without additional methodological and computational efforts. In particular, to achieve an accurate representation of interaction forces between fluid particles and structural elements also for strongly curved interface geometries, the novel sliding boundary particle approach is proposed to ensure full support of SPH particles close to the interface. The coupling of the fluid and the structural field is based on a Dirichlet-Neumann partitioned approach, where the fluid field is the Dirichlet partition with prescribed interface displacements and the structural field is the Neumann partition subject to interface forces. To overcome instabilities inherent to weakly coupled schemes an iterative fixed-point coupling scheme is employed. Several numerical examples in form of well-known benchmark tests are considered to validate the accuracy, stability, and robustness of the proposed formulation. Finally, the filling process of a highly flexible thin-walled balloon-like container is studied, representing a model problem close to potential application scenarios of the proposed scheme in the field of biomechanics.