1989 Fiscal Year Final Research Report Summary
Ultrasonic Levitation of small particles
| Project/Area Number |
63550260
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子通信系統工学
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| Research Institution | College of Industrial Technology, Nihon University |
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Principal Investigator |
SEYA Koichiro College of Indust. Tech., Nihon University, Professor, 生産工学部, 教授 (50059078)
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| Co-Investigator(Kenkyū-buntansha) |
OTSUKA Tetsuro College of Indust. Tech., Nihon University, Lecturer, 生産工学部, 専任講師 (90120394)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Ultrasonic Levitation / Stepped Circular Vibrating Plate / Radiation Pressure / High Intensity Standing Wave Field / Sound Pressure Level / Sound Pressure Distribution / Directional Pattern / Beam Width |
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| Research Abstract |
The purpose of this project was to hold or to levitate small samples in gravity field. The samples are usually contacted to other materials while being located, so that non-contact holding phenomena, levitation, could remove one of the influences to the samples. The sound energy seems to be one of the methods to consider this problem being operated.
This is, high intensity ultrasound field is produced and the samples are inserted in the field, then the radiation pressure are generated to the samples. These samples are floated or levitated in the air at the nodes of sound pressure distribution.
In the first year, an ultrasound unit with stepped circular vibrating plate was set up for the frequencies from 20 kHz to 40 kHz, a single beam directional pattern of 10 degrees beam width was obtained along the center axis of the field. The sound pressure distribution was measured by a 1/8 inch condenser microphone, the sound pressure level was obtained up to 163 db(re. OdB = 20mu Pa). This unit could produce the sufficient ultrasound energy for the experiment on levitation.
The ultrasonic levitation was investigated in the second year. The metal or plastic were used for the test samples, the dimension was cut as sphere, column or triangle pole.
As a results, the samples were levitated at the nodes of the sound pressure, and the higher the density of samples, the higher the sound pressure could be required for the levitation. However, the higher the frequency, the lower the sound pressure was needed for the threshold of levitation. It could be noted that the self rotation was occurred while being levitated. Therefore, the purpose of this project was accomplished by the ultrasonic energy.
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