Ge Liang, Leo Hwa-Liang, Sotiropoulos Fotis, Yoganathan Ajit P
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0335, USA.
J Biomech Eng. 2005 Oct;127(5):782-97. doi: 10.1115/1.1993665.
Time-accurate, fully 3D numerical simulations and particle image velocity laboratory experiments are carried out for flow through a fully open bileaflet mechanical heart valve under steady (nonpulsatile) inflow conditions. Flows at two different Reynolds numbers, one in the laminar regime and the other turbulent (near-peak systole flow rate), are investigated. A direct numerical simulation is carried out for the laminar flow case while the turbulent flow is investigated with two different unsteady statistical turbulence modeling approaches, unsteady Reynolds-averaged Navier-Stokes (URANS) and detached-eddy simulation (DES) approach. For both the laminar and turbulent cases the computed mean velocity profiles are in good overall agreement with the measurements. For the turbulent simulations, however, the comparisons with the measurements demonstrate clearly the superiority of the DES approach and underscore its potential as a powerful modeling tool of cardiovascular flows at physiological conditions. The study reveals numerous previously unknown features of the flow.
在稳定（非脉动）流入条件下，对通过完全开放的双叶机械心脏瓣膜的流动进行了时间精确、全三维数值模拟和粒子图像测速实验室实验。研究了两种不同雷诺数下的流动，一种处于层流状态，另一种处于湍流状态（接近峰值收缩期流速）。对层流情况进行了直接数值模拟，而对湍流则采用两种不同的非定常统计湍流建模方法进行研究，即非定常雷诺平均纳维-斯托克斯（URANS）方法和分离涡模拟（DES）方法。对于层流和湍流情况，计算得到的平均速度剖面与测量结果总体上吻合良好。然而，对于湍流模拟，与测量结果的比较清楚地表明了DES方法的优越性，并突出了其作为生理条件下心血管流动强大建模工具的潜力。该研究揭示了许多以前未知的流动特征。
