Velocity and wall-shear stress measurements of pulsatile flow of blood-analog fluids in elastic vessels

弹性血管中血液模拟流体脉动流的速度和壁剪切应力测量

• 批准号: 449867589
• 负责人: Dr.-Ing. Michael Klaas
• 金额: --
• 依托单位: Lehrstuhl für Strömungslehre und Aerodynamisches Institut (AIA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/449867589?language=en
• 关键词: Velocity; wall; shear; stress; measurements

Nowadays, pathological changes of human blood vessels are one of the major challenges of the modern health care system. In this context, the pulsating blood flow in elastic blood vessels and the resulting wall-shear stress distribution is one of the main factors that influences the mechanisms of arteriosclerosis and, hence, the development of arterial stenosis. Thus, from a medical point of view, precise predictions of the flow field and the unsteady wall-shear stress in human blood vessels are extremely important to assess the indication for surgery or to choose the most promising surgical intervention. For this, it is essential to analyze in detail the underlying problem of the fluid-structure interaction (FSI) of a pulsatile flow and an elastic vessel. From a fluid-mechanical perspective, this problem is characterized by a periodic flow, a vessel with complex geometry, and the interaction of a non-Newtonian fluid with the elastic vessel walls via the time-dependent wall-shear stress distribution. However, the hypothesis that the non-Newtonian rheological behavior of the fluid possesses a significant influence on the FSI via the unsteady periodic wall-shear stress and shear rate has not been investigated yet. It is the scope of this proposal to analyze the fluid-structure interaction between a pulsatile flow of a non-Newtonian, blood-analog fluid and an elastic vessel experimentally with high spatial and temporal resolution. The dilatation of and the flow field in straight and curved elastic vessels as well as symmetrical bifurcations will spatially be determined at high temporal resolution for physiological flow conditions, and the impact of the FSI on the velocity field, the vessel dilatation, and the wall-shear stress distribution will be quantified.

当今，人类血管的病理变化是现代医疗体系面临的主要挑战之一。在这种背景下，弹性血管中的脉动血流和由此产生的壁切应力分布是影响动脉硬化机制从而发展动脉狭窄的主要因素之一。因此，从医学的角度来看，准确预测人体血管内的流场和非定常的壁面剪应力对于评估手术适应症或选择最有希望的手术措施是极其重要的。为此，有必要详细分析脉动流和弹性容器的流固耦合问题。从流体力学的角度来看，该问题具有周期性流动的特点，具有复杂的几何形状，非牛顿流体通过与时间相关的壁面剪应力分布与弹性管壁相互作用。然而，关于流体的非牛顿流变性通过非定常的周期性壁面剪应力和剪切率对FSI产生显著影响的假设尚未得到研究。通过高时空分辨率实验分析了非牛顿类血液流体脉动流与弹性血管之间的流固耦合作用。对于生理流动条件，将在高时间分辨率下确定弹性直管和弯管的扩容和流场以及对称分叉，并量化流固耦合对速度场、血管扩容和壁面剪应力分布的影响。