Modeling hemodynamics in intracranial aneurysms: Comparing accuracy of CFD solvers based on finite element and finite volume schemes.
Modeling hemodynamics in intracranial aneurysms: Comparing accuracy of CFD solvers based on finite element and finite volume schemes.
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DOI：
10.1002/cnm.3111
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发表时间：
2018-09
影响因子：
2.1
通讯作者：
Meng H
中科院分区：
文献类型：
--
作者：
Botti L;Paliwal N;Conti P;Antiga L;Meng H
基于图像的计算流体动力学 (CFD) 已显示出有助于颅内动脉瘤 (IA) 临床管理的潜力，但其在临床实践中的应用一直缺失，部分原因是缺乏准确性评估和敏感性分析。为了对流动控制方程进行数值求解，CFD 求解器通常依赖于两种空间离散化方案：有限体积 (FV) 和有限元 (FE)。由于越来越精确的数值解是通过不同的方式获得的，因此 FV 和 FE 公式的精度和计算成本无法直接比较。为此，在本研究中，我们在模拟患者特定 IA 模型中的流动时对两种代表性 CFD 求解器进行了基准测试：(1) ANSYS Fluent，一种基于 FV 的商业求解器；(2) VMTKLab multidGetto，一种基于不连续 Galerkin (dG) FE 的求解器。通过提高空间网格分辨率（134k、1.1m、8.6m 和 68.5m 四面体单元网格），FV 求解器的精度得到提高。通过增加基本 134k 四面体单元网格上的多项式次数（一次、二次、三次和四次），可以提高 dGFE 求解器的精度。最佳 FV 和 dGFE 近似解被用作误差量化的基线。平均而言，对于 [0,125]cm/s 速度幅度场，第二最佳近似值的速度误差约为 1cm/s。结果表明，与 FV 相比，高阶 dGFE 每个自由度的精度更高，但每个雅可比非零项的精度较差。速度误差的交叉比较表明两个求解器渐近收敛于相同的数值解。然而，未解析的速度场之间的差异表明，网格独立性是通过不同的路径达到的。
Image-based computational fluid dynamics (CFD) has shown potential to aid in the clinical management of intracranial aneurysms (IAs) but its adoption in the clinical practice has been missing, partially due to lack of accuracy assessment and sensitivity analysis. To numerically solve the flow-governing equations CFD solvers generally rely on two spatial discretization schemes: Finite Volume (FV) and Finite Element (FE). Since increasingly accurate numerical solutions are obtained by different means, accuracies and computational costs of FV and FE formulations cannot be compared directly. To this end, in this study we benchmark two representative CFD solvers in simulating flow in a patient-specific IA model: (1) ANSYS Fluent, a commercial FV-based solver and (2) VMTKLab multidGetto, a discontinuous Galerkin (dG) FE-based solver. The FV solver’s accuracy is improved by increasing the spatial mesh resolution (134k, 1.1m, 8.6m and 68.5m tetrahedral element meshes). The dGFE solver accuracy is increased by increasing the degree of polynomials (first, second, third and fourth degree) on the base 134k tetrahedral element mesh. Solutions from best FV and dGFE approximations are used as baseline for error quantification. On average, velocity errors for second-best approximations are approximately 1cm/s for a [0,125]cm/s velocity magnitude field. Results show that high-order dGFE provide better accuracy per degree of freedom but worse accuracy per Jacobian non-zero entry as compared to FV. Cross-comparison of velocity errors demonstrates asymptotic convergence of both solvers to the same numerical solution. Nevertheless, the discrepancy between under-resolved velocity fields suggests that mesh independence is reached following different paths.
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影响因子：
8.3
作者：
Metaxa E;Tremmel M;Natarajan SK;Xiang J;Paluch RA;Mandelbaum M;Siddiqui AH;Kolega J;Mocco J;Meng H
通讯作者：
Meng H
影响因子：
4.1
作者：
Bassi, F.;Crivellini, A.;Rebay, S.
通讯作者：
Rebay, S.
影响因子：
8.3
作者：
Boussel L;Rayz V;McCulloch C;Martin A;Acevedo-Bolton G;Lawton M;Higashida R;Smith WS;Young WL;Saloner D
通讯作者：
Saloner D
影响因子：
10.2
作者：
BABUSKA, I;SURI, M
通讯作者：
SURI, M
DOI：
10.1142/s0218202514400028
发表时间：
2014-07-01
影响因子：
3.5
作者：
Bassi, Francesco;Botti, Lorenzo;Colombo, Alessandro
通讯作者：
Colombo, Alessandro