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，流动将其组织成连贯的涡旋，从人体的交替侧脱落，产生振动力。这种涡流引起的振动是工程设计中深远影响的不良后果，从长圆柱系泊或传输线到桥梁的结构支撑，以及对流体流动的许多其他应用。该项目通过沿圆柱体添加起伏，研究了潜在的方法来减轻不稳定的涡旋模式和相关的振动力。特定的几何形状的灵感来自密封的晶须，这些密封质表明，沿表面的交替散发图案在某些流动条件下会显着降低涡旋诱导的振动。特别有趣的是如何修改起伏的结构背后的尾流以及它将如何影响紧密包装的结构系统。从流体动力传感器阵列，风力涡轮机农场的设计或对不均匀森林檐篷和山区的天气模式的研究，它具有多种潜在的应用。 教育组成部分将包括多个本科研究项目和威斯康星大学 - 麦迪逊大学和波特兰州立大学现有的传播机制的K-12外展计划。这项研究探索了流动圆柱体上流动的基本流体机制，以及受到启发的无封闭式圆柱体的阵列，灵感来自密封粉丝的独特式平台。在临界点和能量传递方面，将通过临界点和其他关键标记来定量识别起伏的几何特征，结果流量和圆柱的力和频率响应之间的因果关系。在单缸数据的基础上，将开发和测试用于大小数组配置的唤醒和尾流相互作用的框架。模拟和风洞实验都将用于涵盖各种流量条件和配置的互补和协作研究计划中。这将通过粒子图像效率测量来实现，以详细测量，直接的数值模拟和大型模拟，以进行时间分辨力和近乎访问区域的机制量化。该奖项反映了NSF的法规任务，并认为通过基金会的知识优点和广泛的criter scritia criter scritia crietia crietia criter criter scritia criter criter criteria criteria crietia criter criteria crietia criteria criteria均值得一提。

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