CAREER: Flow distortions of quiet serrated structures

职业：安静锯齿状结构的流动扭曲

• 批准号: 2402397
• 负责人: Justin Jaworski
• 金额: $ 51.08万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2024-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2402397&HistoricalAwards=false
• 关键词: CAREER; Flow; distortions; quiet; serrated

Acoustic noise is an unavoidable byproduct of flows near aerodynamic structures, where noise is amplified by turbulence interactions with solid bodies. Flow-borne sound contributes to environmental noise levels that are targets for national and international aircraft noise regulations. However, noise also constrains the commercial footprints of wind turbines, emergent commercial unmanned air vehicles, and new paradigms for efficient urban air travel. To address this challenge, serrated edge designs have been adopted in engineering practice, which can affect both the noise level and the fluid dynamics. An acoustic understanding of serrations based on their flow physics remains underdeveloped, where the prevailing noise theory cannot reliably predict changes in noise level. The principal aim of this project is to develop new theoretical models for how edge serrations affect their local fluid flow and their acoustic signature.The objectives of the proposed theoretical research program are to: (1) understand via data reduction of noise experiments how serrations distort incoming flow turbulence; (2) model and predict the distortion of flows pertinent to leading edges and trailing edges; and (3) compute the effect of distorted serrations on local unsteady pressures and the radiated noise. The integrated research and education plan aims to furnish a predictive theoretical framework for serration noise generation, which will be coordinated with global research partners for experimental and numerical validation and will provide international research exchange opportunities for graduate students. This project will also include K-12 educational outreach with the DaVinci Science Center (Allentown, PA), as well as integrate undergraduate research involvement through the Lehigh Biosystems Dynamics Summer Institute (in partnership with Northampton Community College).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.

声噪声是空气动力结构附近流动的不可避免的副产品，在该结构附近，通过与固体体相互作用来扩大噪声。流传播的声音有助于环境噪声水平，这是国家和国际飞机噪声法规的目标。但是，噪音还限制了风力涡轮机的商业足迹，新兴的商业无人驾驶汽车以及新的范式，以实现有效的城市航空旅行。为了应对这一挑战，工程实践中已经采用了锯齿状的边缘设计，这可能会影响噪声水平和流体动力学。基于其流动物理学的锯齿的声学理解仍然不发达，在那里，普遍的噪声理论无法可靠地预测噪声水平的变化。该项目的主要目的是开发新的理论模型，以如何影响其局部流体流量和声学签名。所提出的理论研究计划的目标是：（1）通过减少噪声实验的数据来理解锯齿的信息如何扭曲输入流动湍流； （2）模型并预测与领先边缘和后边缘有关的流量的失真； （3）计算扭曲的锯齿对局部不稳定压力和辐射噪声的影响。综合研究和教育计划旨在为锯齿噪声提供一个预测的理论框架，该框架将与全球研究合作伙伴进行实验和数值验证协调，并将为研究生提供国际研究交流机会。该项目还将包括与Davinci科学中心（宾夕法尼亚州阿伦敦）的K-12教育宣传，以及通过Lehigh Biosystems Dynamics Summer Institute（与Northampton Community College合作）整合本科研究的参与。该奖项颁发了NSF的法定任务，反映了通过评估的Infectian Infactia intiftial crit and Founltial的支持。