King M J, David T, Fisher J
Department of Mechanical Engineering, University of Leeds, UK.
Med Eng Phys. 1997 Apr;19(3):235-41. doi: 10.1016/s1350-4533(96)00066-5.
A three-dimensional (3-D), time-dependent computational fluid dynamics (CFD) model was used to investigate the effect of leaflet opening angle on the flow through a fully open bileaflet heart valve up to peak systole. A laminar flow model of a Newtonian fluid was used, and the peak systolic. Reynolds number was 1500, based on the aortic radius and the average velocity at peak systole. This resulted in a Reynolds number of 5800, based on the aortic radius and the local maximum velocity. The flow fields through and downstream of the bileaflet valves were complex, with strong time-dependent 3-D vortices being found in planes parallel and perpendicular to the leaflets. The parametric study of the effect of leaflet opening angle showed that, as the leaflet opening angle increased from 78 degrees to 85 degrees, the flow downstream of the valve leaflets became more centralized, and the wake downstream of the leaflet decreased in size. However, as the opening angle increased from 78 degrees to 85 degrees, the maximum shear rate and the maximum velocity increased, suggesting that the design of the central orifice geometry was also an important consideration.
采用三维（3 - D）、时间相关的计算流体动力学（CFD）模型，研究瓣叶开口角度对直至收缩期末完全打开的双叶心脏瓣膜内血流的影响。使用了牛顿流体的层流模型，基于主动脉半径和收缩期末的平均速度，收缩期峰值雷诺数为1500。基于主动脉半径和局部最大速度，这导致雷诺数为5800。双叶瓣膜及其下游的流场很复杂，在与瓣叶平行和垂直的平面上发现了强烈的随时间变化的三维涡旋。瓣叶开口角度影响的参数研究表明，随着瓣叶开口角度从78度增加到85度，瓣叶下游的血流变得更加集中，瓣叶下游的尾流尺寸减小。然而，随着开口角度从78度增加到85度，最大剪切率和最大速度增加，这表明中心孔口几何形状的设计也是一个重要的考虑因素。
