The prevention of the low frequency noise problem generated with enlargement of an overflow gate

防止因扩大溢流门而产生的低频噪声问题

• 批准号: 15560195
• 负责人: SATO Yuichi
• 金额: $ 2.3万
• 依托单位: Saitama University
• 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-15560195/
• 关键词: Vibration of water sheet; Self-excited vibration; Stability; Feedback; Nappe; 水脈振動; フラップゲート; ナップ振動; ストローハル数

This report describes the experimental and analytical study on the instability of falling water sheets. Falling water sheets composing enclosed room with behind wall incite their vibration. This phenomenon leads to low frequency pressure's vibration, and it makes trouble that resonates other structures on such as a dam's gate. On this study, we performed laboratory experiments, and confirmed that S products of its frequency and falling time are uniform to figure a little larger than integer. We consider the vibration is caused by feedback of water sheets kinetic energy through air pressure in enclosed room. The result of this analysis shows the figure S must be about integral value+1/4. The vibration can be suppressed by cutting off the feedback with a baffle.

本报告描述了关于下降水层不稳定性的实验和分析研究。下落的水片与墙后组成封闭的房间，引起它们的振动。这种现象会导致低频压力振动，并且会引起大坝闸门等其他结构的共振。在这项研究中，我们进行了实验室实验，并证实其频率和下降时间的S乘积均匀为略大于整数的数字。我们认为振动是由水层动能通过封闭房间内的气压反馈引起的。分析结果表明，数字S一定约为整数值+1/4。可以通过用挡板切断反馈来抑制振动。

项目成果

落下水膜の挙動に関する研究

水膜下落行为研究

• 发表时间: 2004
• 期刊: 日本機械学会講演論文集 4-5
• 作者: 三浦秀一;佐藤勇一;長嶺拓夫;大久保精二;勝浦啓
• 通讯作者: 勝浦啓

佐藤 勇一: "鉛直落下水膜の振動特性"日本機械学会 計測・制御部門講演論文集. (発表予定). (2004)

Yuichi Sato：“垂直下落水膜的振动特性”日本机械工程师学会测量与控制分部讲座论文集（待发表）。

A Study on the Instability offalling Water Sheets

落水层失稳性研究

• 发表时间: 2004
• 期刊: Prepr.of Jpn.Soc.Mech.Eng. No.04-5
• 作者: Shuichi MIURA;Yuichi SATO;Takuo NAGAMINE;Seiji OOKUBO;Kei KATSUURA
• 通讯作者: Kei KATSUURA