Non-Newtonian blood flow study in a model cavopulmonary vascular system
Non-Newtonian blood flow study in a model cavopulmonary vascular system
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模型腔肺血管系统中的非牛顿血流研究
DOI：
10.1002/fld.2256
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发表时间：
2011
影响因子：
1.8
通讯作者：
Chitra K
中科院分区：
文献类型：
--
作者：
Chitra K
利用基于有限元的Navier-Stokes求解器，对模型腔肺血管系统中典型参数范围内的瞬时血流动力学进行了研究。本研究的重点是研究血液的非牛顿行为对血液动力学参数的影响，如壁面切应力(WSS)和流型。计算流体动力学(CFD)模型基于人工可压缩特征分裂(AC-CBS)格式，该格式已被用于在时空域中求解Navier-Stokes方程。用幂定律模型描述了血液的剪切变稀特性与局部应变率的关系。利用该计算模型，对不同频率和不同输入脉冲形式的牛顿流和非牛顿流进行了数值研究。在全腔静脉-肺连接术(TCPC)中观察到的上述情况下的血流动力学参数表明，当考虑血液的非牛顿行为时，WSS的平均分布(约25%-40%)和峰值分布(约50%)有相当大的差异。在非牛顿病例中观察到的较低的WSS水平表明病变形成的风险较高，特别是在较高的脉动频率时。真实的脉冲形式比正弦脉冲相对安全，因为它有更多的能量分布在高次谐波中，这导致更高的平均WSS值。本研究强调了包含非牛顿剪切稀化行为对修复的动脉连接附近的血流进行建模的重要性。版权所有©2010 John Wiley&Sons，Ltd.
A transient haemodynamic study in a model cavopulmonary vascular system has been carried out for a typical range of parameters using a finite element‐based Navier–Stokes solver. The focus of this study is to investigate the influence of non‐Newtonian behaviour of the blood on the haemodynamic quantities, such as wall shear stress (WSS) and flow pattern. The computational fluid dynamics (CFD) model is based on an artificial compressibility characteristic‐based split (AC‐CBS) scheme, which has been adopted to solve the Navier–Stokes equations in space–time domain. A power law model has been implemented to characterize the shear thinning nature of the blood depending on the local strain rate. Using the computational model, numerical investigations have been performed for Newtonian and non‐Newtonian flows for different frequencies and input pulse forms. The haemodynamic quantities observed in total cavopulmonary connection (TCPC) for the above conditions suggest that there are considerable differences in average (about 25–40%) and peak (about 50%) WSS distributions, when the non‐Newtonian behaviour of the blood is taken into account. The lower WSS levels observed for non‐Newtonian cases point to the higher risk of lesion formation, especially at higher pulsation frequencies. A realistic pulse form is relatively safer than a sinusoidal pulse as it has more energy distributed in the higher harmonics, which results in higher average WSS values. The present study highlights the importance of including non‐Newtonian shear thinning behaviour for modelling blood flow in the vicinity of repaired arterial connections. Copyright © 2010 John Wiley & Sons, Ltd.