Understanding the Coupled Interactions Between Hair-Like Micromechanoreceptors and Wall Turbulence

了解毛发状微机械感受器与壁湍流之间的耦合相互作用

• 批准号: 2224849
• 负责人: Ebenezer Gnanamanickam
• 金额: $ 27.49万
• 依托单位: Embry-Riddle Aeronautical University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2224849&HistoricalAwards=false
• 关键词: Understanding; Coupled; Interactions; Between; Hair

The proposed research will focus on understanding the interactions between turbulent flows and long (high aspect ratio), flexible hair-like microstructures or micropillars inspired by those encountered in nature. Some examples include lateral line sensors in fish, airflow sensors in bats and hair cover of animals such as seals and bats. These structures perform several physiological functions such as balance and equilibrium sensors, flow sensors, flight control sensors, thermal regulators and water harvesters. Particularly, hair-cell sensors have such structures which in conjunction with the animal's nervous system forms a mechanoreceptive device i.e., they turn a force or displacement, in response to the flow energy, into a nervous system response. These structures that vibrate in response to the background flow are also important in energy harvesting systems. However, these interactions are poorly understood primarily due to the complexity of the underlying physics. Capturing this physics requires simultaneous, combined measurements of the micropillar motion and the flow velocities which are challenging. The proposed research will use advanced image-based flow diagnostic tools to measure in detail the interactions between arrays of these micropillars and the background flow. The planned outreach activities will target a group that is almost exclusively comprised of students who are under-represented in the sciences, while also being economically disadvantaged. The graduate student supported will be involved in outreach activities, inculcating a spirit of outreach into the next generation of engineers.The interactions between wall turbulence and these micropillars occur in the following manner. Flow structures of scales spanning several orders of magnitude, present within wall turbulence, excites the response of the micropillars. The deflection or vibratory response of the micropillars will then feedback and modify the non-linear, background turbulence, resulting in a non-linearly coupled system. In addition, this interaction occurring at the wall can affect the entire layer resulting in a multiscale interacting layer. Of particular interest are energy transfer pathways between the micropillars and the background turbulence. To describe this coupled interaction and the associated energy transfer mechanisms, advanced diagnostic tools such as multi-camera, multi-resolution, mosaicing particle image velocimetry will be used to capture the dynamics of the background flow while simultaneously tracking the motion of relevant micropillars using particle tracking techniques. Together these tools will provide unique multiscale measurements that will elucidate the coupled physics, advancing fields ranging from physiology to aerospace engineering to non-linear energy systems.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.

拟议的研究将着重于理解湍流与长（高纵横比）之间的相互作用，灵活的头发样微结构或受自然界中遇到的启发的微柱。一些例子包括鱼中的横向传感器，蝙蝠中的气流传感器以及海豹和蝙蝠等动物的发盖。这些结构执行多种生理功能，例如平衡和平衡传感器，流动传感器，飞行控制传感器，热调节器和收割机。尤其是，接发的传感器具有这样的结构，这些结构与动物的神经系统结合形成了机械感受器的装置，即它们响应流动能量，将力或位移变成神经系统的反应。 这些响应背景流动的结构在能量收集系统中也很重要。但是，这些相互作用主要是由于基本物理学的复杂性而被理解的。捕获这种物理学需要同时进行微柱运动的合并测量以及具有挑战性的流速。拟议的研究将使用基于先进的图像流量诊断工具来详细介绍这些微柱和背景流量之间的相互作用。计划中的外展活动将针对一个几乎完全由科学中代表不足的学生组成的小组，同时也处于经济上的不利地位。受支持的研究生将参与外展活动，将宣传精神灌输到下一代工程师中。壁湍流与这些微柱之间的相互作用以以下方式发生。范围跨越壁湍流中的几个数量级的尺度的流量结构激发了微柱的响应。然后，微柱的挠度或振动响应将反馈并修改非线性，背景湍流，从而导致非线性耦合系统。另外，这种相互作用发生在墙壁上会影响整个层，从而导致多尺度相互作用层。特别值得关注的是微柱与背景湍流之间的能量传递途径。为了描述这种耦合的相互作用和相关的能量传递机制，将使用高级诊断工具，例如多型相机，多分辨率，镶嵌粒子图像速度法来捕获背景流的动力学，同时使用粒子跟踪技术跟踪相关微柱的运动。这些工具将共同提供独特的多尺度测量值，以阐明耦合物理，从生理学到航空工程到非线性能源系统的发展领域。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力和更广泛影响的评估来通过评估来提供支持的。