International Research Fellowship Program: Aeroacoustic Model for an Elastic Lifting Surface with a Soft, Sound Absorbant Coating: The Silent Flight of Owls

国际研究奖学金计划：具有柔软吸音涂层的弹性升力表面的气动声学模型：猫头鹰的无声飞行

基本信息

批准号：
0965248
负责人：
Justin Jaworski
金额：
$ 13.31万
依托单位：
Jaworski Justin
依托单位国家：
美国
项目类别：
Fellowship Award
财政年份：
2011
资助国家：
美国
起止时间：
2011-05-01 至 2013-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0965248&HistoricalAwards=false
关键词：
International Research Fellowship Program Aeroacoustic

项目摘要

0965248JaworskiThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Justin Jaworski to work with Drs. Nigel Peake and Timothy J. Pedley at the University of Cambridge in the UK.Owls employ multiple noise suppression features to reduce their acoustic signature within the hearing sensitivity of their prey, much of which is shared by human audition. Two of these noise suppression features, a soft, fibrous velvet material located at certain areas of a wing and an elastic, serrated trailing edge, are thought to work in concert to reduce the effect of background turbulence on noise scattering and to dissipate sound within a large frequency bandwidth. Despite recent efforts to quantify the aeroacoustic effect of a soft coating experimentally, a viable theoretical model does not currently exist. The present research systematically addresses the aeroacoustic impact of these noise suppression mechanisms and isolates the impact of porous media acoustics from the aerodynamic influence of the velvet coating on the flow field. In this manner, the results from the proposed research can be compared directly against experiment and state-of-the-art aeroacoustic computations. Each of the owl noise suppression mechanisms is reduced to physically consistent models that extend analytical aeroacoustics results in the research literature, culminating in a generalized and unified aerodynamic and aeroacoustic framework for a novel computational design tool. The design tool and principles developed from this work will enable quieter future designs for fixed and flapping wing micro air vehicles (MAVs) that operate in flow regimes similar to owls. Lessons learned from this research may also inform sound reduction techniques for lifting surfaces at higher Reynolds and Mach numbers including functionally-silent air vehicles.

0965248Jaworskithe国际研究奖学金计划使美国的科学家和工程师能够在国外进行9到二十四个月的研究。该计划的奖项为联合研究提供了机会，并且在国外使用独特或补充设施，专业知识和实验条件。该奖项将支持贾斯汀·贾沃斯基（Justin Jaworski）博士与博士合作的二十四个月研究奖学金。英国剑桥大学的奈杰尔·皮克（Nigel Peake）和蒂莫西·J·佩德利（Timothy J. 这些噪声抑制特征中的两个，即位于机翼某些区域的柔软，纤维状的天鹅绒材料以及弹性的，锯齿状的后端，可以协同使用，以减少背景湍流对噪声散射的影响，并在较大的频率带宽中散发声音。尽管最近在实验上量化了软涂层的空气效应，但目前尚不存在可行的理论模型。目前的研究系统地解决了这些噪声抑制机制的空气声影响，并分离了多孔介质声学对天鹅绒涂层对流场的空气动力学影响的影响。以这种方式，可以将提出的研究的结果直接与实验和最新的气声计算进行比较。每种OWL噪声抑制机制都简化为物理一致的模型，这些模型扩展了分析的空气声学，从而导致研究文献，最终导致了新型计算设计工具的广义和统一的空气动力学和空气声框架。这项工作开发的设计工具和原理将使未来的设计更安静，用于在类似于猫头鹰的流程中运行的固定和拍打机车（MAV）。从这项研究中学到的经验教训还可能为降低声音的技术提供依据，以在较高的雷诺和马赫数上提升表面，包括功能齐利的空中车辆。