scholarly journals Shape oscillation and stability of an encapsulated microbubble translating in an acoustic wave

2018 ◽  
Vol 144 (4) ◽  
pp. 2189-2200 ◽  
Author(s):  
Yunqiao Liu ◽  
Michael L. Calvisi ◽  
Qianxi Wang
Author(s):  
Ichiro Ueno ◽  
Keishi Matsumoto ◽  
Atsumi Machida ◽  
Tsuyoshi Hanyu

We focus on dynamics of multiple air bubbles exposed to acoustic pressure field while ascending in water. The bubbles are injected into the pool filled with water from a vertical capillary tube, and then the acoustic wave of designated frequency is applied toward the bubbles. The frequency of the acoustic wave is varied from 0.5 to 20 kHz. Volume and shape oscillations of the bubbles are captured by a high-speed camera at frame rates up to 40000 fps with a back-lighting system. Through this system, we succeed in capturing the dynamics of the axisymmetric shape oscillation with a distinct mode number; the bubble exhibits the volume oscillation first with a fundamental frequency f0, and then the gradual transition to the shape oscillation with a fundamental frequency fnm takes place. We evaluate the correlation through the careful observations between the f0 and fnm as f0 ∼ 2.1fnm, which brings almost perfectly confirmation of the prediction through the preceding theoretical works. We also indicate the criterion of the excitation of the shape oscillation by varying the frequencies of the adding pressure field.


1981 ◽  
Vol 42 (C4) ◽  
pp. C4-365-C4-368
Author(s):  
K. L. Bhatia ◽  
M.v. Haumeder ◽  
S. Hunklinger

1995 ◽  
Vol 165 (10) ◽  
pp. 1145 ◽  
Author(s):  
F.V. Bunkin ◽  
Gennadii A. Lyakhov ◽  
K.F. Shipilov
Keyword(s):  

Author(s):  
Bagus Septyanto ◽  
Dian Nurdiana ◽  
Sitti Ahmiatri Saptari

In general, surface positioning using a global satellite navigation system (GNSS). Many satellites transmit radio signals to the surface of the earth and it was detected by receiver sensors into a function of position and time. Radio waves really bad when spreading in water. So, the underwater positioning uses acoustic wave. One type of underwater positioning is USBL. USBL is a positioning system based on measuring the distance and angle. Based on distance and angle, the position of the target in cartesian coordinates can be calculated. In practice, the effect of ship movement is one of the factors that determine the accuracy of the USBL system. Ship movements like a pitch, roll, and orientation that are not defined by the receiver could changes the position of the target in X, Y and Z coordinates. USBL calibration is performed to detect an error angle. USBL calibration is done by two methods. In USBL calibration Single Position obtained orientation correction value is 1.13 ̊ and a scale factor is 0.99025. For USBL Quadrant calibration, pitch correction values is -1.05, Roll -0.02 ̊, Orientation 6.82 ̊ and scale factor 0.9934 are obtained. The quadrant calibration results deccrease the level of error position to 0.276 - 0.289m at a depth of 89m and 0.432m - 0.644m at a depth of 76m


2014 ◽  
Vol 134 (12) ◽  
pp. 1934-1935
Author(s):  
Tsunemasa Saiki ◽  
Yuya Matsui ◽  
Yasuto Arisue ◽  
Yuichi Utsumi ◽  
Akinobu Yamaguchi

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