STUDY ON THE SIMULTANEOUS MEASUREMENTS OF VORTEX MOTIONS AND SOUND SOURCES

涡运动与声源同步测量研究

• 批准号: 13650191
• 负责人: TOYODA Kuniaki
• 金额: $ 2.3万
• 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: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650191/
• 关键词: NOISE; VORTEX; SOUND SOURCES; PRESSURE MEASUREMENTS; PRESSURE MEASUREMENT; JET; MIXING LAYER

The present study reveals the sound-generation mechanism in related to vortex motions, and proposes the ideas to reduce flow-induced noises. The results are summarized as follows.(1) Simultaneous measurements of velocity and fluctuating static-pressure are carried out in an air jet issuing from a sharp-edged circular orifice, and the sound-source terms of the vortex sound theory and the dilatation theory are discussed in relation to vortex motions. The jet is excited in the interaction mode so that velocity and fluctuating static-pressure can be determined in space and time domains by using phase-average technique. The sound-source terms of the theories are obtained from the phase-average velocity and fluctuating static-pressure via the differential process in space and time. The result suggests that intense sound sources are caused by the vortex rolling-up/merging and by the acceleration of vortices during vortex pairing.(2) The intense sound-source regions predicted by pressure measurements correspond to those predicted by the vortex sound theory. The result suggests that the intense sound-source regions can be detected by pressure measurements.(3) The noise propagating from the separated mixing layer from a fence is strongly correlated to the sound source related to the vortex motions.(4) In order to reduce the noise from the separated flow from the front pillar and the side mirror of an automobile, the effects of the devices to suppress vortex evolutions are investigated experimentally. The results show that the devices are very effective to suppress the vortex motions related to sound sources.

本研究揭示了与涡旋运动有关的发声机制，并提出了减少流动引起的噪音的想法。结果总结如下。（1）同时测量速度和波动的静态压力，在从尖锐的圆形孔发出的空气喷射中进行，并以与涡旋运动的关系讨论了涡流声理论的声音术语，并讨论了扩张理论。射流在相互作用模式下是激发的，因此可以使用相位平均技术在空间和时域中确定速度和波动的静态压力。这些理论的声音术语是通过空间和时间上的差分过程从相平均速度和波动的静态压力中获得的。结果表明，强烈的音源是由涡旋滚动/合并以及涡旋配对过程中涡流加速引起的。（2）强烈的声音源区域由压力测量所预测的强烈声音源区域对应于与涡旋声理论预测的相对应的。结果表明，可以通过压力测量来检测强烈的声音源区域。（3）从栅栏分离的混合层传播的噪声与与涡流运动相关的声源密切相关。（4）为了减少从前颗粒和自动摩托杆的侧视镜的效果，对vortect vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort vort。结果表明，这些设备非常有效地抑制与声源相关的涡旋运动。

项目成果

Kuniaki Toyoda, Riho Hiramoto: "Detection of Vortex Motions and Sound Sources in Jets"Abstract of The Fifth China-Japan Workshop on Turbulent Flows. 17 (2002)

Kuniaki Toyoda、Riho Hiramoto：《射流中涡运动和声源的检测》第五届中日湍流研讨会摘要。

Toyoda, K. and Hiramoto, R: "Detection of Vortex Motions and Sound Sources in Jets by Pressure Measurements"Proc. Of The first International Symposium on Advanced Fluid Information. 439-444 (2001)

Toyoda, K. 和 Hiramoto, R：“通过压力测量检测喷气机中的涡流运动和声源”Proc。

Kuniaki Toyoda, Riho Hiramoto: "Detection of Vortex Motions and Sound Sources in Jets"Abstract of The Fifth China-Japan Workshop on Turbulent Flows. 17-17 (2002)

Kuniaki Toyoda、Riho Hiramoto：《射流中涡运动和声源的检测》第五届中日湍流研讨会摘要。

Riho Hiramoto, Kuniaki Toyoda: "Study on Sound Source of a Circular Jet by Simultaneous Measurements of Velocity and Pressure Fluctuations"Proc. of The Fifth JSME-KSME Fluids Engineering Conference. 02-207(CD-ROM). OS6-1 (2002)

Riho Hiramoto、Kuniaki Toyoda：“通过速度和压力波动的同时测量来研究圆形射流的声源”Proc。

Hiramoto, R. and Toyoda, K.: "Study on Sound Source of a Circular Jet by Simultaneous Measurements of Velocity and Pressure Fluctuations"Proc. Of The Fifth JSME-KSME Fluids Engineering Conference (CD-ROM). OS6-1. (2002)

Hiramoto, R. 和 Toyoda, K.：“通过速度和压力波动的同时测量来研究圆形射流的声源”Proc。