论文标题

浸入血流模拟的边界有限元法

Immersed boundary finite element method for blood flow simulation

论文作者

Bourantas, G. C., Lampropoulos, D. L., Zwick, B. F., Loukopoulos, V. C., Wittek, A., Miller, K.

论文摘要

我们提出了一个有效,准确的沉浸式边界(IB)有限元(Fe)求解器,用于求解不可压缩的Navier - Stokes方程。特别强调具有复杂几何形状的内部流(血管系统中的血流)。 IB方法在计算上对于内部流量来说是昂贵的,这主要是由于流量域以外的网格点很大。在这项研究中,我们采用了局部改进策略以及域还原方法,以减少覆盖流域的网格并增加流量域内的网格节点的百分比。提出的方法使用增量压力校正方案(IPC)利用有效,准确的FE求解器,以及实施IB方法的边界条件来求解瞬态,不可压缩的Navier-稳定流动方程。我们使用圆柱体中的Poiseuille流量分析解决方案来验证数值方法的准确性。我们通过考虑复杂的几何形状(例如动脉瘤血管中的血流和主动脉)的流量构型来进一步研究所提出方法的准确性和适用性,否则大多数IB方法将难以解决这些流动构型。正如验证示例所证明的那样,我们的方法具有很高的精度和高效率,这是通过在架子上固定的笔记本电脑上复杂几何形状中的血流解决方案所证明的。

We present an efficient and accurate immersed boundary (IB) finite element (FE) solver for numerically solving incompressible Navier--Stokes equations. Particular emphasis is given to internal flows with complex geometries (blood flow in the vasculature system). IB methods are computationally costly for internal flows, mainly due to the large percentage of grid points that lie outside the flow domain. In this study, we apply a local refinement strategy, along with a domain reduction approach in order to reduce the grid that covers the flow domain and increase the percentage of the grid nodes that fall inside the flow domain. The proposed method utilizes an efficient and accurate FE solver with the incremental pressure correction scheme (IPCS), along with the boundary condition enforced IB method to numerically solve the transient, incompressible Navier--Stokes flow equations. We verify the accuracy of the numerical method using the analytical solution for Poiseuille flow in a cylinder. We further examine the accuracy and applicability of the proposed method by considering flow within complex geometries, such as blood flow in aneurysmal vessels and the aorta, flow configurations which would otherwise be extremely difficult to solve by most IB methods. Our method offers high accuracy, as demonstrated by the verification examples, and high efficiency, as demonstrated through the solution of blood flow within complex geometry on an off-the-shelf laptop computer.

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