STUDY ON THEREDUCTION OF AERODYNAMIC NOISE BY VORTEX CONTROL

涡控制降低气动噪声的研究

基本信息

批准号：
15560151
负责人：
TOYODA Kuniaki
金额：
$ 2.05万
依托单位：
HOKKAIDO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560151/
关键词：
AERODYNAMIC NOISE JET VORTEX CONTROL SEPARATED FLOW SOUND SOURCE

项目摘要

The objective of the present study is to obtain the basic materials for the vortex control techniques to reduce the aerodynamic noise. The results are summarized as follows.(1)The effect of tabs (vortex generators) on jet noise was investigated by flow visualization experiments and phase-average measurements. The results reveal the interaction mechanism of vortex rings and streamwise vortices to lead to the suppression of sound generation. In particular, it is very important in engineering applications to make clear the cut-and-reconnection mechanism of the streamwise vortices wound around the vortex rings and to confirm the suppression of vortex pairing.(2)The effect of pile-fabrics on reducing aerodynamic noise was investigated by measuring the noise from a square cylinder in uniform flow. The results show that the pile-fabrics on the cylinder are effective to suppress the vortex evolution and pairing of separated flow and to reduce the noise related to the vortex motions.(3)The sound source of the separated mixing layer from a fence was discussed by the measurements of velocity and pressure fluctuations. The results reveal that the sound source intensity is high in the regions of vortex evolution and pairing. The propagated sound detected simultaneously with flow visualization also suggests that the sound source is closely related to the vortex motions.(4)Based on the results of the present study and the related studies, the vortex control techniques to reduce aerodynamic noise are proposed, and the future works are suggested.

本研究的目的是获取涡流控制技术的基本材料，以减少空气动力学噪声。结果总结如下。（1）通过流动可视化实验和相平均测量结果研究了TABS（Vortex发电机）对喷射噪声的影响。结果揭示了涡流环和流向涡流的相互作用机理，从而导致声音产生的抑制。特别是，在工程应用中非常重要的是，清除流向涡流的剪切和连接机制周围围绕涡旋环缠绕并确认抑制涡旋配对。（2）通过测量在均匀流量的方形圆柱体中测量平方缸的噪声来调查桩贴剂对减少空气动力学噪声的影响。结果表明，气缸上的桩贴有效地抑制了分离流动的涡旋演化和配对，并减少与涡流运动相关的噪声。（3）通过速度和压力波动的测量来讨论从围栏的分离混合层的声源。结果表明，在涡旋演化和配对的区域中，声源强度很高。与流动可视化同时检测到的传播声音还表明，声源与涡流动作密切相关。（4）基于本研究的结果和相关研究的结果，提出了减少空气动力学噪声的涡流控制技术，并提出了未来的工作。