2015 Fiscal Year Final Research Report
Study on directionality and behavior of microbubble and solid particles in acoustic streaming caused by ultrasonic wave irradiation
Project/Area Number |
25420109
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Fluid engineering
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Research Institution | University of Fukui |
Principal Investigator |
Ohta Junichi 福井大学, 工学(系)研究科(研究院), 教授 (20168941)
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Project Period (FY) |
2013-04-01 – 2016-03-31
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Keywords | 混相流 / マイクロバブル / 超音波 / 音響放射力 |
Outline of Final Research Achievements |
Using YAG laser, fluorescent particles (tracers for liquid) and microbubbles could be distinguished by critical hue angles, thus the present image processing enabled us to measure the gas-liquid (or solid-liquid) velocities simultaneously. At a frequency of 96kHz, acoustic radiation force caused only MB to move. At a f = 3.5MHz, the surrounding liquid velocity (acoustic streaming) was less than 10 % of MB velocity. In a microbubble-liquid mixture, primary acoustic radiation force and buoyancy force were dominant in motion of microbubble, fluid drag and second Bjerknes force were negligible. In a solid-liquid mixture, gas attached on particles, reflection ratio, and so on affected the behavior of the mixture, besides gravity and drag force. When acoustic radiation force was dominant, the acoustic directivity function affected the the behavior of solid particles.
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Free Research Field |
工学
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