Bistatic acoustic scattering from trapped gas bubbles in sandy sediments

1994 ◽  
Vol 96 (5) ◽  
pp. 3219-3219
Author(s):  
Frank A. Boyle ◽  
Nicholas P. Chotiros
Keyword(s):  
Acoustic Scattering ◽  
Gas Bubbles ◽  
Trapped Gas ◽  
Sandy Sediments

scholarly journals Nonlinear acoustic scattering from trapped gas bubbles in sandy sediments

1995 ◽  
Vol 98 (5) ◽  
pp. 2978-2978
Author(s):  
Frank A. Boyle ◽  
Nicholas P. Chotiros
Keyword(s):  
Acoustic Scattering ◽  
Gas Bubbles ◽  
Nonlinear Acoustic ◽  
Trapped Gas ◽  
Sandy Sediments

Dynamic Characterization of a Valveless Micropump Considering Entrapped Gas Bubbles

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Songjing Li ◽  
Jixiao Liu ◽  
Dan Jiang
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Experimental Studies ◽  
Gas Bubbles ◽  
Chamber Pressure ◽  
Dynamic Characterization ◽  
Valveless Micropump ◽  
Performance Deterioration ◽  
Trapped Gas

Unexpected gas bubbles in microfluidic devices always bring the problems of clogging, performance deterioration, and even device functional failure. For this reason, the aim of this paper is to study the characterization variation of a valveless micropump under different existence conditions of gas bubbles based on a theoretical modeling, numerical simulation, and experiment. In the theoretical model, we couple the vibration of piezoelectric diaphragm, the pressure drop of the nozzle/diffuser and the compressibility of working liquid when gas bubbles are entrapped. To validate the theoretical model, numerical simulation and experimental studies are carried out to investigate the variation of the pump chamber pressure influenced by the gas bubbles. Based on the numerical simulation and the experimental data, the outlet flow rates of the micropump with different size of trapped gas bubbles are calculated and compared, which suggests the influence of the gas bubbles on the dynamic characterization of the valveless micropump.

Slow viscous flow near a superhydrophobic surface with trapped gas bubbles

PAMM ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 651-652
Author(s):  
Aleksei Ageev ◽  
Irina Golubkina ◽  
Alexander Osiptsov
Keyword(s):  
Viscous Flow ◽  
Superhydrophobic Surface ◽  
Gas Bubbles ◽  
Slow Viscous Flow ◽  
Trapped Gas

scholarly journals Direct measurement of trapped gas bubbles by capillarity on the pore scale

2009 ◽  
Vol 1 (1) ◽  
pp. 3189-3196 ◽  
Author(s):  
Tetsuya Suekane ◽  
Nguyen Hoan Thanh ◽  
Takuya Matsumoto ◽  
Masumi Matsuda ◽  
Masanori Kiyota ◽  
...  
Keyword(s):  
Direct Measurement ◽  
Gas Bubbles ◽  
Pore Scale ◽  
Trapped Gas

Direct Observation of Trapped Gas Bubbles by Capillarity in Sandy Porous Media

2009 ◽  
Vol 82 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Tetsuya Suekane ◽  
Na Zhou ◽  
Takahiro Hosokawa ◽  
Takuya Matsumoto
Keyword(s):  
Porous Media ◽  
Direct Observation ◽  
Gas Bubbles ◽  
Trapped Gas

Raman investigations on laser-trapped gas bubbles

1997 ◽  
Vol 277 (4) ◽  
pp. 331-334 ◽  
Author(s):  
M. Lankers ◽  
J. Popp ◽  
G. Rössling ◽  
W. Kiefer
Keyword(s):  
Gas Bubbles ◽  
Trapped Gas

Distributions of physonect siphonulae in the Gulf of Maine and their potential as important sources of acoustic scattering

2003 ◽  
Vol 60 (7) ◽  
pp. 759-772 ◽  
Author(s):  
Mark C Benfield ◽  
Andone C Lavery ◽  
Peter H Wiebe ◽  
Charles H Greene ◽  
Timothy K Stanton ◽  
...  
Keyword(s):  
Gulf Of Maine ◽  
Acoustic Scattering ◽  
Gas Bubbles ◽  
Resonance Region ◽  
Acoustic Resonance ◽  
Depth Range ◽  
Potential Control ◽  
In Situ Investigation ◽  
Horizontal Layers

The distributions of siphonulae stages of physonect siphonophores were mapped in Wilkinson, Jordan, and Georges basins of the Gulf of Maine using a video plankton recorder. Siphonulae are often overlooked in net samples and our optical survey appears to be the first in situ investigation of these organisms. Siphonulae were distributed at mid-depths in narrow horizontal layers, suggesting potential control of their buoyancy. The siphonulae possessed gas-filled pneumatophores with diameters of 0.1–0.4 mm. Pneumatophore diameters appeared to be similar over their entire sampled depth range, suggesting that siphonulae may be capable of regulating the pressure of gas within the pneumatophore to maintain a constant volume. The dimensions of the siphonulae pneumatophores placed them near the acoustic resonance region for scattering at 43 kHz when near the surface and 120 kHz when at depth. Theoretical estimates of the acoustical target strengths of gas bubbles of sizes corresponding to the sizes of our measured pneumatophores produced relatively strong backscatter. Layers of siphonulae corresponded to regions of high acoustical backscatter at 120, 200, and 420 kHz.

Modeling and Influence Study of Gas Bubbles on Characteristics of a Piezoelectric Valve-Less Micropump

2012 ◽  
Author(s):  
Songjing Li ◽  
Jixiao Liu ◽  
Dan Jiang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Dynamic Pressure ◽  
Experimental Studies ◽  
Gas Bubbles ◽  
Video Camera ◽  
Pump Chamber ◽  
High Speed Video Camera ◽  
Outlet Flow ◽  
Trapped Gas

The aim of this paper is to develop a theoretical model of a piezoelectric valve-less micropump for liquid delivery with entrapped gas bubbles and evaluate the influence of gas bubbles on the dynamic characteristics of the micropump by using this model. In the model, we consider the vibration of piezoelectric diaphragm, the pressure loss through the nozzle/diffuser and the compressibility of working liquids with entrapped gas bubbles. In order to validate the developed model and make it useful as a design and prediction tool, experimental studies are carried out to investigate the flow rate and dynamic pressure inside the pump chamber when gas bubbles are absent or present in the micropump. The presence of gas bubbles inside the pump chamber is also observed with a high-speed video camera. The outlet flow rate of the micropump with different size of trapped gas bubbles are calculated and compared.

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