NSF/FDA SIR: Development of new measurement tools for accurate estimation of wall-shear stress in medical devices using Particle Image Velocimetry (PIV) methods

vlachos, Pavlos p .心血管血流受到高剪切速率的影响，从而导致粒子图像测速测量的大速度动态范围。这样的测量有很大的误差，最终污染了随后的剪切应力估计。为了克服这些限制，他们建议开发和演示一种PIV处理方法，该方法对剪切速率具有鲁棒性，并提供扩展的测量动态范围。此外，与依靠速度场导数估计来计算壁面剪切应力的传统范例相反，他们将开发一种直接计算流动颗粒模式的完整变形的新方法。因此，他们将能够直接估计涡度和剪切应力，而不依赖于任何速度场的后处理。最后，他们将探讨壁面位置和壁面与流体的相互作用对速度和剪应力估计的影响。这些发展与最先进的创新进步相对应，有望显着提高心血管装置中壁剪切应力估计的准确性。

ABSTRACT #1239265Vlachos, Pavlos P.Cardiovascular flows are subject to high shear rates that result in large velocity dynamic range for particle image velocimetry measurements. Such measurements are subject to high errors that ultimately contaminate subsequent shear stress estimation. In order to overcome such limitations they propose to develop and demonstrate a PIV processing methodology that is robust to shear rate and offers an extended measurement dynamic range. Furthermore in contrast to the traditional paradigm that relies on velocity field derivative estimation for calculating the wall shear stress they will develop a novel approach that directly calculates the complete deformation of a flow particle pattern. As a result trhey will be able to directly estimate vorticity and shear stress without relying on any post processing of the velocity field. Finally, they will explore the effect of the wall position and wall interaction with the flow on the velocity and shear stress estimation. These developments correspond to state of the art innovative advancements that promise to dramatically improve the accuracy with which wall shear stresses are estimated in cardiovascular devices.