Study on the cleaning effect by ultrasonic cavitation accompanying with a water jet

超声空化伴水射流清洗效果研究

• 批准号: 11650161
• 负责人: TOMITA Yukio
• 金额: $ 2.3万
• 依托单位: Hokkaido University of Education
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650161/
• 关键词: Cavitation; Bubble; Ultrasonic waves; Water Jet; Underwater Acoustics; Cleaning; Shock Waves; Bubble Microjet; 液体マイクロジェット

During the first term of the research project, we primarily investigated the characteristic of ultrasonically produced cavitation. Cavitation was ultrasonically generated in tap water by using an ultrasonic vibrator with the resonance frequency of 28kHz. The behavior of cavitation was observed with a high-speed video camera. Impulsive pressures caused by cavitation were measured with a pressure transducer and cavitation noise measurement was also conducted by using a hydrophone. The signals were fed into a FFT analyzer to examine their power spectra.During the second term, we carried out an experiment for understanding the cleaning effect due to fluid motion by employing a nickel plate covered with a PbCl_2 film several μm thick as a test wall. The individual nickel plates were set on the surface of an upper static wall and exposed to three different situations of fluid motion such as (1) flow induced only by a water jet, (2) flow induced only by an ultrasonic cavitation and (3) flow induced by (1) combined with (2). The damaged surface of the nickel plate was observed by employing a microscope equipped with a CCD camera. It was found that the film separation took place in all situations, (1)-(3), depending on the forces acting on the wall surface.Furthermore cavitation bubble dynamics has been investigated by means of several methods of theoretical approach. Some of the results obtained have been published in several journals.

在研究项目的第一个学期，我们主要研究了超声产生的空化特性。利用共振频率为28kHz的超声振动器在自来水中超声产生空化现象。用高速摄像机对空化行为进行了观察。用压力传感器测量了空化引起的脉冲压力，用水听器测量了空化噪声。这些信号被送入FFT分析仪来检测它们的功率谱。在第二学期，我们利用覆盖了几μm厚的PbCl_2薄膜的镍板作为测试壁，进行了流体运动清洗效果的实验。将单个镍板放置在上部静壁面上，并暴露在三种不同的流体运动情况下，即：(1)仅由水射流诱导的流动，(2)仅由超声空化诱导的流动和(3)由(1)和(2)联合诱导的流动。利用配备CCD相机的显微镜对镍板的损伤表面进行观察。研究发现，在(1)-(3)的所有情况下，膜分离都会发生，这取决于作用在壁面上的力。此外，还采用几种理论方法研究了空化气泡动力学。获得的一些结果已发表在几家期刊上。

项目成果

Y.Tomita: "Some aspects of the motion of two laser-produced cavitation bubbles near a free surface"To be presented at the 1UTAM Symposium on "Free Surface Flows", Birmingham, U. K., 10-14 July, 2000. (2000)

Y.Tomita：“自由表面附近两个激光产生的空化气泡运动的某些方面”将于 2000 年 7 月 10-14 日在英国伯明翰举行的 1UTAM “自由表面流”研讨会上发表。(2000)

Y.Tomita: "Some aspects of the motion of two laser-produced cavitation bubbles near a free surface"To be published in Free Surface Flows edited by J.R.Blake and A.C.King, Kluwer Academic Publishers. (2001)

Y.Tomita：“自由表面附近两个激光产生的空化气泡运动的某些方面”将发表在 J.R.Blake 和 A.C.King 编辑的《Free Surface Flows》上，Kluwer 学术出版社。

佐藤光太郎: "振動壁まわりの気泡の挙動と圧力分布に及ぼすクリアランスの影響"日本学術会議キャビテーションに関するシンポジウム(第10回). 15-18 (1999)

Kotaro Sato：“间隙对气泡行为和振动壁周围压力分布的影响”日本科学委员会空化研讨会（第 10 期）（1999 年）。

T.Kodama and Y.Tomita: "Cavitation bubble behavior and bubble-shock wave interaction near a gelatin surface as a study of in vivo bubble dynamics"Applied Physics B. 70. 139-149 (2000)

T.Kodama 和 Y.Tomita：“明胶表面附近的空化气泡行为和气泡冲击波相互作用作为体内气泡动力学的研究”应用物理学 B.70.139-149 (2000)

T.Kodama: "Cavitation bubble behavior and bubble-shock wave interaction near a gelatin surface as a study of in vivo bubble dynamics"Applied Physics B.Lasers and Optics. 70. 139-149 (2000)

T.Kodama：“明胶表面附近的空化气泡行为和气泡冲击波相互作用作为体内气泡动力学的研究”应用物理学 B. 激光和光学。