Collaborative Proposal: Linking the topographic features of bio-inspired undulated cylinders to their force reduction properties using critical points

合作提案：使用临界点将仿生波状圆柱体的地形特征与其减力特性联系起来

• 批准号: 2037582
• 负责人: Raul Cal
• 金额: $ 23.95万
• 依托单位: Portland State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2037582&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Linking; topographic; features

As a fluid moves around a cylindrical or similarly shaped structure, the flow organizes into coherent vortices, which shed from alternate sides of the body producing a vibrational force. This vortex-induced-vibration is an undesirable consequence with far-reaching effects in engineering design, from long cylindrical mooring or transmission lines to structural supports of bridges, as well as many other applications susceptible to fluid flow. This project investigates potential methods to mitigate the unsteady vortex pattern and associated vibrational force by adding undulations along the cylinder. The specific geometry is inspired by the whiskers of seals which have shown that an alternating undulation pattern along the surface significantly reduces the vortex-induced-vibration under certain flow conditions. Of particular interest is how the wake behind the undulated structures can be modified and how it, in turn, would impact a system of closely packed structures. This has a variety of potential applications from hydrodynamic sensor arrays, the design of wind turbine farms, or the study of weather patterns over non-uniform forest canopies and mountainous terrain. The educational components will include multiple undergraduate research projects and K-12 outreach programming integrated into existing dissemination mechanisms at University of Wisconsin-Madison and Portland State University.This research explores the fundamental fluid mechanisms of flow over undulated cylinders and arrays of undulated cylinders inspired by the unique topography of seal whiskers. Causal links between the geometric features of the undulations, the resulting flow features, and the force and frequency response of the cylinder will be quantitatively identified by critical points and other key markers within the wake in terms of momentum and energy transfer. Building upon the single-cylinder data, a framework for wake-wake and wake-structure interactions will be developed and tested for small and large array configurations. Both simulations and wind tunnel experiments will be utilized in a complementary and collaborative research plan that spans a large range of flow conditions and configurations. This will be accomplished through particle-image-velocimetry for detailed wake measurements as well as direct numerical simulation and large-eddy simulations for time-resolved forces and quantification of mechanisms in the near-wake region.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当流体围绕圆柱形或类似形状的结构移动时，流动会组织成连贯的涡流，这些涡流从身体的两侧脱落，产生振动力。这种涡流引起的振动是一种不良后果，对工程设计产生深远影响，从长圆柱形系泊或传输线到桥梁的结构支撑，以及许多其他容易受到流体流动影响的应用。该项目研究了通过沿着圆柱体添加波动来减轻不稳定涡流模式和相关振动力的潜在方法。特定几何形状的灵感来自于密封件的晶须，该晶须已表明沿表面的交替波动图案可显着减少某些流动条件下的涡流引起的振动。特别令人感兴趣的是如何修改起伏结构背后的尾流，以及它反过来如何影响紧密堆积的结构系统。这具有多种潜在应用，包括流体动力学传感器阵列、风力涡轮机发电场的设计或不均匀森林冠层和山区天气模式的研究。 教育部分将包括多个本科生研究项目和 K-12 外展计划，并整合到威斯康星大学麦迪逊分校和波特兰州立大学现有的传播机制中。这项研究受海豹晶须独特地形的启发，探索了波状圆柱体和波状圆柱体阵列上流动的基本流体机制。波动的几何特征、由此产生的流动特征以及圆柱体的力和频率响应之间的因果关系将通过尾流中动量和能量传递方面的关键点和其他关键标记来定量识别。基于单缸数据，将为小型和大型阵列配置开发和测试尾流-尾流和尾流-结构相互作用的框架。模拟和风洞实验将用于涵盖大范围流动条件和配置的互补和协作研究计划。这将通过用于详细尾流测量的粒子图像测速以及用于时间分辨力的直接数值模拟和大涡模拟以及近尾流区域机制的量化来完成。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Multicolor dye-based flow structure visualization for seal-whisker geometry characterized by computer vision

• DOI: 10.1088/1748-3190/ad0aa8
• 发表时间: 2023-11
• 期刊: Bioinspiration & Biomimetics
• 影响因子: 3.4
• 作者: O. Ferčák;Kathleen Lyons;Christin T Murphy;Kristina M. Kamensky;R. B. Cal;Jennifer A Franck

Effects of wavelength on vortex structure and turbulence kinetic energy transfer of flow over undulated cylinders

• DOI: 10.1007/s00162-023-00661-2
• 发表时间: 2022-06
• 期刊: Theoretical and Computational Fluid Dynamics
• 影响因子: 3.4
• 作者: Kathleen Lyons;R. B. Cal;Jennifer A. Franck