Tetrahedral vs. polyhedral mesh size evaluation on flow velocity and wall shear stress for cerebral hemodynamic simulation
Tetrahedral vs. polyhedral mesh size evaluation on flow velocity and wall shear stress for cerebral hemodynamic simulation
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DOI：
10.1080/10255842.2010.518565
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发表时间：
2011-01-01
影响因子：
1.6
通讯作者：
Karmonik, Christof
中科院分区：
文献类型：
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作者：
Spiegel, Martin;Redel, Thomas;Karmonik, Christof
血流动力学因素，特别是壁剪切应力（wss）可能对脑动脉瘤的生长和破裂有重要影响。由于无法在体内可靠地测量WSS，计算流体动力学（CFD）模拟经常被用于可视化和量化患者特定计算模型的血流。随着人们对将这些CFD模拟集成到预处理规划中的兴趣日益增加，需要更好地理解计算参数（如体积单元类型、网格尺寸和网格组成）的有效性。在本研究中，比较了多面体和终末型两种最常见的动脉瘤类型（囊状和终末型）的CFD结果。基于四面体的网格并讨论了未来的临床应用。为此，为每个动脉瘤构建一组具有空间变化的表面和体积网格配置的模型（网格尺寸范围：519 - 258,481体积单元）。比较了模型壁上的WSS分布和基于点的速度测量结果。我们的研究结果表明，多面体网格在收敛速度和更均匀的WSS模式方面具有优势。从最简单的网格（仅四面体单元）和最先进的网格设计（带边界层的多面体网格）中，WSS值和血流速度的计算变化在0.84 - 6.3%之间。
Haemodynamic factors, in particular wall shear stresses (WSSs) may have significant impact on growth and rupture of cerebral aneurysms. Without a means to measure WSS reliably in vivo, computational fluid dynamic (CFD) simulations are frequently employed to visualise and quantify blood flow from patient-specific computational models. With increasing interest in integrating these CFD simulations into pretreatment planning, a better understanding of the validity of the calculations in respect to computation parameters such as volume element type, mesh size and mesh composition is needed. In this study, CFD results for the two most common aneurysm types (saccular and terminal) are compared for polyhedral-vs. tetrahedral-based meshes and discussed regarding future clinical applications. For this purpose, a set of models were constructed for each aneurysm with spatially varying surface and volume mesh configurations (mesh size range: 5119-258, 481 volume elements). WSS distribution on the model wall and point-based velocity measurements were compared for each configuration model. Our results indicate a benefit of polyhedral meshes in respect to convergence speed and more homogeneous WSS patterns. Computational variations of WSS values and blood velocities are between 0.84 and 6.3% from the most simple mesh (tetrahedral elements only) and the most advanced mesh design investigated (polyhedral mesh with boundary layer).