A Numerical Study of Aortic Flow Stability and Comparison With In Vivo Flow Measurements
A Numerical Study of Aortic Flow Stability and Comparison With In Vivo Flow Measurements
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DOI：
10.1115/1.4023132
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发表时间：
2013-01-01
影响因子：
1.7
通讯作者：
Xu, X. Y.
中科院分区：
文献类型：
--
作者：
Kousera, C. A.;Wood, N. B.;Xu, X. Y.
工程过渡性湍流模型的发展以及随后对一些病变的心血管流动的评估和验证表明，该模型可能在正常的主动脉中有用。20世纪70年代初用导管安装的热膜测速仪获得的人体大动脉实验数据的存在，为比较该模型在此类流动中的性能提供了机会。从一名年轻志愿者的磁共振解剖和速度图像中提取的普通人体主动脉，作为改变雷诺数(Re)和沃斯利参数(α)的基础，以匹配来自人类升主动脉的四个实验数据点，其中两个有扰动流动，两个明显没有扰动流动。用三种不同的流入湍流强度(Tu)进行了试验，以找出单一水平是否可以代表4000；Re；10,000和17<；Alpha；26这四种不同的情况。一个必要的边界条件包括入流“湍流”水平，并且在入流Tu=1.0%的所有四种情况下都得到了令人信服的结果，这为过渡模型在较大动脉中的应用提供了额外的信心。基于雷诺平均Navier-Stokes(RANS)的剪切应力输运(SST)过渡模型能够在较低的入流湍流强度(1.0%)下捕捉到正确的人体主动脉内流动状态。[DOI：10.1115/1.4023132]
The development of an engineering transitional turbulence model and its subsequent evaluation and validation for some diseased cardiovascular flows have been suggestive of its likely utility in normal aortas. The existence of experimental data from human aortas, acquired in the early 1970s with catheter-mounted hot film velocimeters, provided the opportunity to compare the performance of the model on such flows. A generic human aorta, derived from magnetic resonance anatomical and velocity images of a young volunteer, was used as the basis for varying both Reynolds number (Re) and Womersley parameter (alpha) to match four experimental data points from human ascending aortas, comprising two with disturbed flow and two with apparently undisturbed flow. Trials were made with three different levels of inflow turbulence intensity (Tu) to find if a single level could represent the four different cases with 4000 < Re < 10,000 and 17 < alpha < 26. A necessary boundary condition includes the inflow "turbulence" level, and convincing results were obtained for all four cases with inflow Tu = 1.0%, providing additional confidence in the application of the transitional model in flows in larger arteries. The Reynolds-averaged Navier-Stokes (RANS)-based shear stress transport (SST) transitional model is capable of capturing the correct flow state in the human aorta when low inflow turbulence intensity (1.0%) is specified. [DOI: 10.1115/1.4023132]