理想弯曲动脉中生理血流发展对常用壁面剪应力度量的影响
The influence of physiological flow development on popular wall shear stress metrics in an idealized curved artery
摘要：
我们数值研究二次流模式和随后的壁面剪切应力分布在弯曲动脉模型的流动发展的影响，我们计算血管指标通常用于评估血流特性的变化，因为它适用于动脉疾病。我们用一个简单的，刚性的180度弯曲管模拟人体动脉，该管具有圆形横截面和恒定曲率，忽略锥度，扭转和弹性的影响。高保真度的数值结果计算从一个内部的不连续谱元素流解算器。本研究中使用的流速为生理流速。我们进行这项研究，使用牛顿血液模拟流体进行脉动流与两个流入条件。第一流动条件完全发展，而第二条件未发展（即均匀）。我们观察和讨论的差异，出现在生理波形的快速加速和减速阶段的二次流模式，我们直接连接的强度变化，这些二次流模式沿曲率的壁面剪切应力指标的差异，为每个入口条件。结果表明，在未开发的条件下，降低轴向速度产生不太强烈的二次流，反过来，降低了壁面剪应力矢量的振荡和多向性质，我们将这种影响与计算应力度量的异常。这些结果表明，潜在的较低的患病率，在弯曲的入口流量是相当不发达的生理相关的结果，以进一步了解血流发展对疾病的影响。
英文摘要：
We numerically investigate the influence of flow development on secondary flow patterns and subsequent wall shear stress distributions in a curved artery model, and we compute vascular metrics commonly used to assess variations in blood flow characteristics as it applies to arterial disease. We model a human artery with a simple, rigid 180-degree curved tube with circular cross-section and constant curvature, neglecting effects of taper, torsion and elasticity. High-fidelity numerical results are computed from an in-house discontinuous spectral element flow solver. The flow rate used in this study is physiological. We perform this study using a Newtonian blood-analog fluid subjected to a pulsatile flow with two inflow conditions. The first flow condition is fully developed while the second condition is undeveloped (i.e. uniform). We observe and discuss differences in secondary flow patterns that emerge over the rapid acceleration and deceleration phases of the physiological waveform, and we directly connect the variation in intensity of these secondary flow patterns along the curvature to differences in the wall shear stress metrics for each entrance condition. Results indicate that decreased axial velocities under an undeveloped condition produce less intense secondary flow that, in turn, reduces both the oscillatory and multidirectional nature of the wall shear stress vector, and we link this effect to abnormalities in computed stress metrics. These results suggest potentially lower prevalence of disease in curvatures where entrance flow is rather undeveloped-a physiologically relevant result to further understand the influence of blood flow development on disease.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
