A numerical study of pulsatile blood flow in an eccentric catheterized artery using a fast algorithm

The pulsatile blood flow in an eccentric catheterized artery is studied numerically by making use of an extended version of the fast algorithm of Borges and Daripa [J. Comp. Phys., 2001]. The mathematical model involves the usual assumptions that the arterial segment is straight, the arterial wall is rigid and impermeable, blood is an incompressible Newtonian fluid, and the flow is fully developed. The flow rate (flux) is considered as a periodic function of time (prescribed). The axial pressure gradient and velocity distribution in the eccentric catheterized artery are obtained as solutions of the problem. Through the computed results on axial pressure gradient, the increases in mean pressure gradient and frictional resistance in the artery due to catheterization are estimated. These estimates can be used to correct the error involved in the measured pressure gradients using catheters.     

屋盖结构脉动风压非高斯特性分析的极限流线方法

非高斯脉动风压对围护结构及局部结构构件有较大影响,在设计中应引起足够重视。目前,非高斯风压场的分区研究主要是建立在对实验数据的统计量分析基础上,并非普遍适用,且随机性较强,区内统计特征值亦相差很大,不足以显示不同区域的非高斯程度,故须结合其形成机理加以分析。考虑到在特定风场条件下分离流动及旋涡作用范围具有时均定常的特点,利用稳态数值方法求解的极限流线和粘性流动分离理论的基本结论,结合实验结果分析了典型屋盖结构脉动风压非高斯特性的形成和分布机理。结果表明,极限流线的分布形态与实验统计的偏度及峰态值分布高度相关,可以被很好地应用于风压场非高斯特性的生成及分布机理研究。