Wall shear-rate estimation within the 50cc Penn State artificial heart using particle image velocimetry
Wall shear-rate estimation within the 50cc Penn State artificial heart using particle image velocimetry
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DOI：
10.1115/1.1784477
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发表时间：
2004-08-01
影响因子：
1.7
通讯作者：
Deutsch, S
中科院分区：
文献类型：
--
作者：
Hochareon, P;Manning, KB;Deutsch, S
颗粒图像测速（PIV）作为一种常规的流体机械设备流场评估工具，已经得到了越来越多的认可。我们已经开发了一种算法来研究50cc宾夕法尼亚州立大学人工心脏内的壁剪切率，使用低放大，传统的粒子图像测速（PIV）。壁剪切与血栓形成有关，这是人工心脏植入后的一个主要问题。为了解决与近壁测量相关的壁散射和测量体积不完整的问题，我们引入了零掩蔽和流体质心移动技术。采用不同的速度场进行了模拟，以评估其可行性。随后，将该技术应用于所收集的实验数据。结果表明，审问区的大小应选择尽可能小，以最大限度地提高分辨率，而足够大，以确保每个区域有足够的粒子数量。在目前的研究中，一个16 × 16的询问窗口具有良好的空间分辨率和粒子密度，用于估计壁面剪切速率。利用PIV开发的技术可以一次从大量地点获得壁面剪切率估计。由于可以相对快速地确定流场的平面图像，PIV可能在任何初步设计过程中都是有用的。
Particle image velocimetry (PIV) has been gaining acceptance as a routine tool to evaluate the flow fields associated with fluid mechanical devices. We have developed algorithms to investigate the wall shear-rates within the 50cc Penn State artificial heart using low magnification, conventional particle image velocimetry (PIV). Wall shear has been implicated in clot formation, a major post-implant problem with artificial hearts. To address the issues of wall scattering and incomplete measurement volumes, associated with near wall measurements, we have introduced a zero masking and a fluid centroid shifting technique. Simulations using different velocity fields were conducted with the techniques to assess their viability. Subsequently, the techniques were applied to the experimental data collected. The results indicate that the size of the interrogation region should be chosen to be as small as possible to maximize resolution while large enough to ensure an adequate number of particles per region. In the current study, a 16 x 16 interrogation window performed well with good spatial resolution and particle density for the estimation of wall shear rate. The techniques developed with PIV allow wall shear-rate estimates to be obtained from a large number of sites at one time. Because a planar image of a flow field can be determined relatively rapidly, PIV may prove useful in any preliminary design procedure.