Asgharzadeh Hafez, Borazjani Iman
Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, USA.
Comput Math Methods Med. 2016;2016:7412926. doi: 10.1155/2016/7412926. Epub 2016 Oct 26.
The effects of Reynolds and Womersley numbers on the hemodynamics of two simplified intracranial aneurysms (IAs), that is, sidewall and bifurcation IAs, and a patient-specific IA are investigated using computational fluid dynamics. For this purpose, we carried out three numerical experiments for each IA with various Reynolds (Re = 145.45 to 378.79) and Womersley (Wo = 7.4 to 9.96) numbers. Although the dominant flow feature, which is the vortex ring formation, is similar for all test cases here, the propagation of the vortex ring is controlled by both Re and Wo in both simplified IAs (bifurcation and sidewall) and the patient-specific IA. The location of the vortex ring in all tested IAs is shown to be proportional to Re/Wo which is in agreement with empirical formulations for the location of a vortex ring in a tank. In sidewall IAs, the oscillatory shear index is shown to increase with Wo and 1/Re because the vortex reached the distal wall later in the cycle (higher resident time). However, this trend was not observed in the bifurcation IA because the stresses were dominated by particle trapping structures, which were absent at low Re = 151.51 in contrast to higher Re = 378.79.
利用计算流体动力学研究了雷诺数和沃默斯利数对两种简化颅内动脉瘤(IA),即侧壁型和分叉型IA以及一个患者特异性IA血流动力学的影响。为此,我们针对每个IA进行了三次数值实验,采用了不同的雷诺数(Re = 145.45至378.79)和沃默斯利数(Wo = 7.4至9.96)。尽管此处所有测试案例的主导流动特征,即涡环形成,是相似的,但在简化的IA(分叉型和侧壁型)以及患者特异性IA中,涡环的传播受Re和Wo两者控制。所有测试IA中涡环的位置显示与Re/Wo成正比,这与水箱中涡环位置的经验公式一致。在侧壁型IA中,振荡剪切指数显示随Wo和1/Re增加,因为涡环在周期后期到达远端壁(驻留时间更长)。然而,在分叉型IA中未观察到这种趋势,因为应力由颗粒捕获结构主导,与较高的Re = 378.79相比,在低Re = 151.51时不存在这种结构。
Comput Math Methods Med. 2016
J Biomech Eng. 2010-11
Comput Math Methods Med. 2016
J R Soc Interface. 2017-5
J Biomech Eng. 2001-10
Front Cardiovasc Med. 2021-12-23
AJNR Am J Neuroradiol. 2019-10-24
J Biomech Eng. 2015-11
J Long Term Eff Med Implants. 2015
J R Soc Interface. 2015-4-6
Proc Natl Acad Sci U S A. 2014-3-17
AJNR Am J Neuroradiol. 2014-2
Ann Biomed Eng. 2013-4-20
Acta Neurochir (Wien). 2012-8-29
AJNR Am J Neuroradiol. 2012-3