摘要:
实验研究微尺度射流流场中微细梁发生的振动过程,并提出基于该原理测量微尺度射流速度.实验使用长度56. 2mm、直径约0. 07mm铜丝作为微细梁,使用直径约0. 36mm喷管产生的微尺度射流.使用高速摄影仪观察射流流速在2. 7~27. 3m/s间梁振动的变化.试验结果发现当射流喷嘴对准梁3/5处时,振动过程中振幅随射流速度上升.而当射流喷嘴对准梁的9/10和3/4处时,在高流速下,振幅不随流速上升.使用霍尔传感器和磁铁测量梁的振动,当喷嘴对准梁的3/4处,霍尔传感器输出电压有效值随射流流速线性增长.但在其他位置,由于磁铁改变了梁的均匀结构,振动随流速的变化不规律.
关键词:
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微尺度 /
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微细梁 /
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测速 /
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霍尔电压
Abstract:
In the experiment, the vibration of a micro cantilever varying with the jet velocity is studied. It is suggested to measure the micro scale jet velocity based on this mechanism. A copper thread with length 56.2mm, diameter 0.07mm is used as the micro cantilever. The jet velocity comes from a micro nozzle with diameter 0.36mm. The vibration of cantilever is investigated with a high-speed camera while the jet velocity varying between 2.7~27.3m/s.The result shows that the vibration amplitude increase with the jet velocity while the nozzle is amied at 3/5 of the canti-lever length.But while the nozzle is aimed at 9/10 or 3/5 of the cantilever length, the amplitude stops increasing at high jet veloicty. A hall sensor and a magnet are used to measure the vibra-tion. The output voltage increases linearly with the jet velocity, while the nozzle is aimed at the 3/4 of the cantilver lenth. But at the other positions, the viburation is not inneratic because the attached magnet change the mass distribuion of the cantilever.
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