动脉瘤内流场以及瘤体尺寸的影响的数值研究

采用计算流体动力学(CFD)数值模拟的方法,在周期性脉动速度入流条件下,建立刚性动脉瘤模型并研究了动脉瘤模型中流场的特征(速度、压力、壁面剪切应力)。得到了脉动入流一个周期内流场特征的变化规律,发现动脉瘤的后端有相当高的压力和壁面剪切应力,而且高压力和壁面剪切应力分布的位置几乎是固定的。探讨了不同动脉瘤尺寸对内部流场的影响,动脉瘤的直径与瘤体长度之比越大,瘤壁承受的剪切应力就越大,动脉瘤破裂的危险性就越高。

Numerical Research on Flow Field in Aneurysm and Dimension Influence

With the inflow boundary condition of periodic pulsatile velocity,rigid aneurysm model is established and the features (velocity,pressure and wall shear stress) of the flow field in aneurysm are investigated numerically. The characteristics of flow field within a cycle are acquired,fairly high pressure and wall shear stress almost remain stationary at the distal end of aneurysm. The influence of bulge size on inner flow field was researched,a larger ratio of diameter to bulge length leads to higher wall shear stress,and the aneurysm with large ratio of diameter to bulge length tends to a dangerous rupture.