论文标题
Robin-Neumann方案,具有用于分区流体结构相互作用的准Newton加速度
A Robin-Neumann Scheme with Quasi-Newton Acceleration for Partitioned Fluid-Structure Interaction
论文作者
论文摘要
Dirichlet-Neumann方案是用于流体结构相互作用(FSI)的最常见分区算法,并且具有针对两个子问题所采用的求解器具有很高的灵活性。然而,这并非没有缺点:首先,固有的添加质量效应通常会严重破坏数值解决方案。此外,Dirichlet-Neumann方案不能应用于FSI问题,在FSI问题中,不可压缩的流体被Dirichlet边界完全封闭,因为它无法满足体积约束。在过去的十年中,界面准Newton方法已被证明可以通过在Dirichlet-Neumann耦合中添加类似牛顿的更新步骤来控制添加的质量效果并大大加快收敛性。但是,它们对不可压缩难题没有影响。作为替代方案,罗宾·尼曼(Robin-Neumann)方案通过包括库奇应力将流体的边界条件推广到罗宾条件。尽管这种修改实际上成功地解决了Dirichlet-Neumann方法的两个缺点,但要支付的价格是对Robin加权参数的强烈依赖,并且对良好选择的先验知识非常有限。这项工作提出了一种策略,以合并这两个想法并从其综合优势中受益。将产生的准Newton加速性Robin-Neumann方案与Robin-和Dirichlet-Neumann变体进行了比较。数值测试表明,它不仅提供了更快的收敛性,而且大大降低了罗宾参数的影响,从而减轻了罗宾·尼姆曼算法的主要缺点。
The Dirichlet-Neumann scheme is the most common partitioned algorithm for fluid-structure interaction (FSI) and offers high flexibility concerning the solvers employed for the two subproblems. Nevertheless, it is not without shortcomings: to begin with, the inherent added-mass effect often destabilizes the numerical solution severely. Moreover, the Dirichlet-Neumann scheme cannot be applied to FSI problems in which an incompressible fluid is fully enclosed by Dirichlet boundaries, as it is incapable of satisfying the volume constraint. In the last decade, interface quasi-Newton methods have proven to control the added-mass effect and substantially speed up convergence by adding a Newton-like update step to the Dirichlet-Neumann coupling. They are, however, without effect on the incompressibility dilemma. As an alternative, the Robin-Neumann scheme generalizes the fluid's boundary condition to a Robin condition by including the Cauchy stresses. While this modification in fact successfully tackles both drawbacks of the Dirichlet-Neumann approach, the price to be paid is a strong dependency on the Robin weighting parameter, with very limited a priori knowledge about good choices. This work proposes a strategy to merge these two ideas and benefit from their combined strengths. The resulting quasi-Newton-accelerated Robin-Neumann scheme is compared to both Robin- and Dirichlet-Neumann variants. The numerical tests demonstrate that it does not only provide faster convergence, but also massively reduces the influence of the Robin parameter, mitigating the main drawback of the Robin-Neumann algorithm.