A sharp interface Lagrangian-Eulerian method for rigid-body fluid-structure interaction
A sharp interface Lagrangian-Eulerian method for rigid-body fluid-structure interaction
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DOI：
10.1016/j.jcp.2021.110442
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发表时间：
2020-03
影响因子：
4.1
通讯作者：
E. M. Kolahdouz;A. Bhalla;L. Scotten;B. Craven;Boyce E. Griffith
中科院分区：
文献类型：
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作者：
E. M. Kolahdouz;A. Bhalla;L. Scotten;B. Craven;Boyce E. Griffith
本文介绍了一种模拟刚体在粘性不可压缩流体中的流固耦合问题的锐界面方法。这种方法的能力是基准使用一系列的测试案例，并证明使用大规模的生物医学FSI模型。本文开发的数值方法，我们称之为浸没拉格朗日-欧拉（ILE）方法，通过求解流体和固体子域的单独动量方程，集成了分区和浸没FSI制剂的各个方面，如在分区制剂中，同时还使用动态流体和结构区域的非一致离散化，如在浸没制剂中。一个简单的狄利克雷-诺依曼耦合方案，其中的运动的浸没固体是由流体牵引力驱动的评估沿着的流体-结构界面，和运动的流体沿着该接口被约束，以匹配固体速度，从而满足无滑移条件。为了开发一种实用的数值方法，我们采用了一种惩罚方法，该方法近似地沿流体-结构界面沿着施加无滑移条件。在耦合策略中，流体-结构界面的单独离散化通过刚性弹簧状惩罚力被拴系到体积实体网格。我们的流固耦合方案依赖于浸没界面法（IIM）离散的几何形状，这使得精确的速度和应力沿沿着复杂的内部接口的测定。流固耦合的数值方法可能会受到与附加质量效应相关的不稳定性的影响，但计算测试表明，本文介绍的方法在广泛的固体-流体质量密度比范围内（包括极小、几乎相等、相等和较大的密度比）对选定的测试用例保持稳定。生物医学FSI演示案例包括使用该方法在脉冲复制器中模拟双叶机械心脏瓣膜的动力学，以及在下腔静脉的患者平均解剖模型中模拟血凝块的运输所获得的结果。
This paper introduces a sharp interface method to simulate fluid-structure interaction (FSI) involving rigid bodies immersed in viscous incompressible fluids. The capabilities of this methodology are benchmarked using a range of test cases and demonstrated using large-scale models of biomedical FSI. The numerical approach developed herein, which we refer to as an immersed Lagrangian-Eulerian (ILE) method, integrates aspects of partitioned and immersed FSI formulations by solving separate momentum equations for the fluid and solid subdomains, as in a partitioned formulation, while also using non-conforming discretizations of the dynamic fluid and structure regions, as in an immersed formulation. A simple Dirichlet-Neumann coupling scheme is used, in which the motion of the immersed solid is driven by fluid traction forces evaluated along the fluid-structure interface, and the motion of the fluid along that interface is constrained to match the solid velocity and thereby satisfy the no-slip condition. To develop a practical numerical method, we adopt a penalty approach that approximately imposes the no-slip condition along the fluid-structure interface. In the coupling strategy, a separate discretization of the fluid-structure interface is tethered to the volumetric solid mesh via stiff spring-like penalty forces. Our fluid-structure coupling scheme relies on an immersed interface method (IIM) for discrete geometries, which enables the accurate determination of both velocities and stresses along complex internal interfaces. Numerical methods for FSI can suffer from instabilities related to the added mass effect, but computational tests indicate that the methodology introduced here remains stable for selected test cases across a broad range of solid-fluid mass density ratios, including extremely small, nearly equal, equal, and large density ratios. Biomedical FSI demonstration cases include results obtained using this method to simulate the dynamics of a bileaflet mechanical heart valve in a pulse duplicator, and to model transport of blood clots in a patient-averaged anatomical model of the inferior vena cava.