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Ultrasonic Levitation of small particles

小颗粒的超声波悬浮

基本信息

批准号：
63550260
负责人：
SEYA Koichiro
金额：
$ 0.83万
依托单位：
College of Industrial Technology, Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550260/
关键词：
Ultrasonic Levitation Stepped Circular Vibrating Plate Radiation Pressure High Intensity Standing Wave Field Sound Pressure Level Sound Pressure Distribution Directional Pattern Beam Width 超音波浮揚中心駆動振幅分布 dB たわみ振動波長音源同相

项目摘要

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.

该项目的目的是在重力场中保持或悬浮小样本。样品在定位时通常会与其他材料接触，因此非接触保持现象（悬浮）可以消除对样品的影响之一。声能似乎是考虑这个问题的操作方法之一。即产生高强度超声场并将样品插入场中，然后对样品产生辐射压力。这些样品在声压分布节点处漂浮或悬浮在空气中。第一年，设置了一个带有阶梯式圆形振动板的超声单元，频率从20 kHz到40 kHz，沿场中心轴获得了10度波束宽度的单波束方向图。通过1/8英寸电容式麦克风测量声压分布，获得的声压级高达163db(re.OdB=20muPa)。该装置可以产生足够的超声波能量用于悬浮实验。第二年开始研究超声波悬浮。测试样品采用金属或塑料，尺寸被切割成球体、柱体或三角柱。因此，样品在声压节点处悬浮，样品的密度越高，悬浮所需的声压就越高。然而，频率越高，悬浮阈值所需的声压越低。可以注意到，自旋转是在悬浮时发生的。因此，这个项目的目的是通过超声波能量来完成的。