Fluid‐structure interaction of a pulsatile flow with an aortic valve model: A combined experimental and numerical study
Fluid‐structure interaction of a pulsatile flow with an aortic valve model: A combined experimental and numerical study
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DOI：
10.1002/cnm.2945
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发表时间：
2018-04
影响因子：
2.1
通讯作者：
J. Sigüenza;D. Pott;S. Mendez;S. Sonntag;T. Kaufmann;U. Steinseifer;F. Nicoud
中科院分区：
文献类型：
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作者：
J. Sigüenza;D. Pott;S. Mendez;S. Sonntag;T. Kaufmann;U. Steinseifer;F. Nicoud
通过实验和数值模拟研究了与血液流过具有柔性瓣叶的心脏瓣膜相关的复杂流固耦合问题。在实验装置中，脉冲复制器产生通过仿生刚性主动脉根部的脉动流，其中植入具有聚合物柔性小叶的主动脉瓣模型。同时进行瓣叶运动的高速记录和粒子图像测速测量，以研究瓣膜运动学和血流动力学。大涡模拟相同的配置，基于浸入边界法的变体，也提出了。将大规模并行非结构化有限体积流求解器与有限元固体力学求解器耦合，以预测非定常流与阀门之间的流体-结构相互作用。进行详细的分析的动态打开和关闭的瓣膜，显示出良好的定量协议之间的实验和模拟的全球行为，尽管一些差异，关于个别的动态的瓣叶。多周期分析（超过20个周期）能够表征阀门下游湍流的产生，显示实验和模拟之间相似的流动特征。当血流开始减速时，血流在峰值收缩期后转变为湍流。在瓣膜尾流中观察到波动，在主动脉的连合侧观察到最大振幅。总的来说，一个非常有前途的实验与模拟比较显示，证明了数值方法的潜力。
The complex fluid‐structure interaction problem associated with the flow of blood through a heart valve with flexible leaflets is investigated both experimentally and numerically. In the experimental test rig, a pulse duplicator generates a pulsatile flow through a biomimetic rigid aortic root where a model of aortic valve with polymer flexible leaflets is implanted. High‐speed recordings of the leaflets motion and particle image velocimetry measurements were performed together to investigate the valve kinematics and the dynamics of the flow. Large eddy simulations of the same configuration, based on a variant of the immersed boundary method, are also presented. A massively parallel unstructured finite‐volume flow solver is coupled with a finite‐element solid mechanics solver to predict the fluid‐structure interaction between the unsteady flow and the valve. Detailed analysis of the dynamics of opening and closure of the valve are conducted, showing a good quantitative agreement between the experiment and the simulation regarding the global behavior, in spite of some differences regarding the individual dynamics of the valve leaflets. A multicycle analysis (over more than 20 cycles) enables to characterize the generation of turbulence downstream of the valve, showing similar flow features between the experiment and the simulation. The flow transitions to turbulence after peak systole, when the flow starts to decelerate. Fluctuations are observed in the wake of the valve, with maximum amplitude observed at the commissure side of the aorta. Overall, a very promising experiment‐vs‐simulation comparison is shown, demonstrating the potential of the numerical method.