支架治疗动脉瘤流固耦合数值模拟的周期重复性研究

目的探讨瘤用支架血流动力学流固耦合数值模拟过程中不同计算周期的相对误差大小,以给出获得收敛结果的最小周期推荐值.方法利用有限元分析软件 ANSYS对植入不同截面形状支架治疗梭形动脉瘤模型进行流固耦合数值模拟.每个模型进行3个周期的迭代计算,计算出各模型的动脉瘤腔内血液流速、压力、壁面切应力等血流动力学参数.最后比较相邻周期的相对误差绝对值,根据数据后处理结果得到计算的最佳周期数.结果各模型的动脉瘤腔内血流动力学参数计算1周期与计算2周期的相对误差绝对值远高于5%,重复计算3个周期与计算2个周期的相对误差绝对值均小于5%.结论有限元分析软件 ANSYS进行支架非定常血流动力学流固耦合数值模拟计算时,计算2个周期可达一定精确度,避免不必要的时间消耗,为支架治疗梭形动脉瘤的流固耦合数值模拟研究提供参考依据.

Periodic repeatability of FSI numerical simulation for stented aneurysm

Objective This study focused on the relative errors in the fluid-structure interaction （FSI） of numerical simulation for stented aneurysm between different computing cycles, and intended to recommend the minimum periods for obtaining the convergent iteration results. Methods The finite element analysis software ANSYS was adopted to simulate the FSI of fusiform aneurysm treated with different cross-section shape stents. Three cardiac cycles of iteration were performed for each model. Hemodynamic parameters, such as blood flow, pressure, wall shear stress and so on, were calculated and analyzed. The optimal computing cycle was obtained from the comparison of the relative errors between different cycles. Results The relative errors of all the parameters of the first cycle and the second cycle are far larger than 5% , and the relative errors of the second cycle and the third cycle are less than 5%. Conclusions The minimum calculation period recommended was two cycles in numerical simulation of FSI for stented aneurysm. The results provided some theoretical guidance to the numerical simulation of FSI in the treatment of fusiform aneurysms with stents.