Multicolor dye-based flow structure visualization for seal-whisker geometry characterized by computer vision
Multicolor dye-based flow structure visualization for seal-whisker geometry characterized by computer vision
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DOI：
10.1088/1748-3190/ad0aa8
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发表时间：
2023-11
影响因子：
3.4
通讯作者：
O. Ferčák;Kathleen Lyons;Christin T Murphy;Kristina M. Kamensky;R. B. Cal;Jennifer A Franck
中科院分区：
文献类型：
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作者：
O. Ferčák;Kathleen Lyons;Christin T Murphy;Kristina M. Kamensky;R. B. Cal;Jennifer A Franck
鳍足类触毛具有独特且复杂的三维地形，具有有益的流体流动特性，例如阻力、升力和涡流引起的振动的大幅减少。为了理解和利用这些效应，必须研究下游涡动力学。染料可视化是捕获这些下游效应的传统定性方法，特别是在复杂设备可能令人望而却步的比较生物学研究中。高保真数值模拟或实验粒子图像测速对于定量高分辨率流量测量来说很常见，但计算成本昂贵，需要昂贵的设备，并且测量窗口有限。本研究建立了一种利用新颖但直观的计算机视觉技术从海豹晶须几何形状的标准染料可视化实验中提取定量数据的方法，该技术保持简单性和有利的大实验观察窗口，同时自动提取涡流频率、位置和平流。将结果与可比较几何形状的直接数值模拟 (DNS) 数据进行比较。功率谱和斯特劳哈尔数显示，雷诺数为 500 时，方法之间的行为一致，雷诺数为 250 时，在规范几何波长 3.43 处具有最小值，峰值频率为 0.2。涡流跟踪显示，从卷起到下游晶须直径 3.5 倍的速度明显增加，与 DNS 数据有很强的重叠，但在有限的 DNS 窗口之外显示出稳定的结果。这项研究提供了对有价值的仿生工程模型的深入了解，同时推进了一种可以轻松应用于广泛的比较生物学研究的分析方法。
Pinniped vibrissae possess a unique and complex three-dimensional topography, which has beneficial fluid flow characteristics such as substantial reductions in drag, lift, and vortex induced vibration. To understand and leverage these effects, the downstream vortex dynamics must be studied. Dye visualization is a traditional qualitative method of capturing these downstream effects, specifically in comparative biological investigations where complex equipment can be prohibitive. High-fidelity numerical simulations or experimental particle image velocimetry are commonplace for quantitative high-resolution flow measurements, but are computationally expensive, require costly equipment, and can have limited measurement windows. This study establishes a method for extracting quantitative data from standard dye visualization experiments on seal whisker geometries by leveraging novel but intuitive computer vision techniques, which maintain simplicity and an advantageous large experimental viewing window while automating the extraction of vortex frequency, position, and advection. Results are compared to direct numerical simulation (DNS) data for comparable geometries. Power spectra and Strouhal numbers show consistent behavior between methods for a Reynolds number of 500, with minima at the canonical geometry wavelength of 3.43 and a peak frequency of 0.2 for a Reynolds number of 250. The vortex tracking reveals a clear increase in velocity from roll-up to 3.5 whisker diameters downstream, with a strong overlap with the DNS data but shows steady results beyond the limited DNS window. This investigation provides insight into a valuable bio-inspired engineering model while advancing an analytical methodology that can readily be applied to a broad range of comparative biological studies.