生物瓣膜流固耦合分析的PISO算法研究
Analyzing Fluid-solid Coupling of Bioprosthetic Heart Valve with PISO Algorithm

应用任意拉格朗日欧拉法推导了生物瓣膜与血液的耦合方程，并借助压力隐式算子分割算法对血液的动量方程进行离散，得到耦合过程的速度迭代方程。根据Fluent中的压力隐式算子分割算法PISO （Pressure implicit with splitting of operators）对生物瓣膜模型进行动态力学分析，得到了生物瓣膜的变形情况。仿真分析结果显示生物瓣膜的变形主要发生在每片瓣叶的自由边，而腹部的变形较小，而且在瓣膜打开的过程中自由边会出现卷曲。对生物瓣膜使用同样的环境进行脉动流实验模拟，得到了相同的结果。仿真和实验结果证明，该方法可以用在生物瓣膜的流固耦合分析中，同时也为生物瓣膜的进一步优化提供了参考。
This paper deduced the coupling equations of biological heart valve and blood with the Arbitrary Lagrange-Euler(ALE) method, and discretized the momentum equation of blood with the pressure-implicit splitting of operators(PISO) algorithm. The velocity iteration equation of the coupling process is obtained. Then, the PISO was carried out with the Fluent software, and the mathematical model of the valve deformation was obtained. The computer simulation results show that the valve deformation mainly occurs on the free edge of each leaflet and that the abdomen deformation is small and that the free edge curls during the valve opening. The experiments on the pulsatile flow of the valve were also performed, and the experimental results agree with the simulation results. The simulation and experimental results show that this method can be used to analyze the fluid-solid coupling of the bioprosthetic heart valve, providing some reference for its further optimization