Study on the generating mechanism and prevention equipment of low frequency self-excited sound by air flow

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560250
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Dynamics/Control
• Research Institution: Saitama University
• Principal Investigator: NAGAMINE Takuo 埼玉大学, 理工学研究科, 准教授 (00323379)
• Co-Investigator(Kenkyū-buntansha): SATO Yuichi 埼玉大学, 大学院理工学研究科, 教授 (30134828) ; MORI Hiroki 九州大学, 工学研究院, 准教授 (50451737)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 自励音 / ウインドスロッブ / 空力騒音 / 低周波

Outline of Final Research Achievements

Self-excited sound caused by flow is observed in the vehicle cabin, when the vehicle runs with an open window. This phenomenon is called wind-throb. In this study, we measure the sound pressure at the vehicle cabin and the Helmholtz resonator in laboratory. We also explore the possibility of suppression of self-excited sound generated by fluid resonant oscillation. We tried to prevention of wind-throb by using of a baffle plate. A baffle plate is set inside of the vehicle’s cabin. Accordingly, in this study the baffle plate prevents from occurring wind-throb. As equipment, a baffle plate is installed, the flow of air is changed, and vortices are emitted outside. The form and the attachment position of this baffle plate were examined.

Free Research Field

機械力学