A Model and a Numerical Solver for the Flow Generated by an Air-Bubble Curtain in Initially Stagnant Water

Abstract The particle image velocimetry measurement technique was used to measure the whole-volume, three-dimensional, transient velocity field generated by a single air bubble rising in stagnant water in a small diameter pipe. The three-dimensional flow field was reconstructed using a stereoscopic technique. Conditional averages of the velocity fields for the situations when the bubble rises close to the center of the pipe, and close to the pipe wall were determined, and the turbulent motion generated in the continuous liquid phase for both situations was studied.

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Best practice of using air-bubble curtains as part of complex fish protection structures

Vodosnabzhenie i sanitarnaia tehnika ◽

10.35776/vst.2021.11.03 ◽

2021 ◽

pp. 24-32

Author(s):

В.Д. Шульгин ◽

С.С. Набоков

Keyword(s):

Best Practice ◽

Hydraulic Calculation ◽

Air Bubble ◽

Functional Efficiency ◽

Standard Values ◽

The Operating Mechanism ◽

Technical Features ◽

Fish Protection ◽

Bubble Curtain ◽

Protection Structures

Приведены результаты исследований работы комплексных рыбозащитных сооружений с использованием воздушно-пузырьковых завес. Дано описание механизма работы комплексных рыбозащитных сооружений и принципа работы воздушно-пузырьковой завесы. На основе гидравлического расчета разработана методика проектирования и применения воздушно-пузырьковой завесы в составе комплексных рыбозащитных сооружений. Приведены результаты исследований по оценке функциональной эффективности построенных комплексных рыбозащитных сооружений. Комплексные рыбозащитные сооружения, имеющие в своем составе запани и воздушно-пузырьковые завесы и работающие в эрлифтном режиме, достаточно эффективно защищают молодь рыб. При правильно подобранных параметрах работы оборудования и выбранном створе размещения сооружений, с учетом гидравлических и технических особенностей водозабора, их эффективность гарантированно превышает нормативные значения. The results of studying the operation of complex fish protection structures with the use of air-bubble curtains are presented. A description of the operating mechanism of complex fish protection structures and the principle of operation of the air-bubble curtain is given. On the basis of a hydraulic calculation, a method for designing and using an air-bubble curtain as part of complex fish protection structures has been developed. The results of estimating the functional efficiency of the built complex fish protection structures are presented. The complex fish protection structures that include debris deflectors and air-bubble curtains and operate in an air-lift mode, effectively protect fish fry. Provided the operating parameters of the equipment and the selected alignment of the structures with account of the hydraulic and technical features of the water intake have been correctly chosen, their efficiency is guaranteed to exceed the standard values.

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A basic study to determine the barrier effect of an air bubble curtain in the whiteleg shrimp, Litopenaeus vannamei

NIPPON SUISAN GAKKAISHI ◽

10.2331/suisan.76.210 ◽

2010 ◽

Vol 76 (2) ◽

pp. 210-212 ◽

Cited By ~ 1

Author(s):

KEISHI MATSUDA ◽

SETSUO NOHARA ◽

TAKESHI NOMURA ◽

MARCY N. WILDER

Keyword(s):

Litopenaeus Vannamei ◽

Barrier Effect ◽

Basic Study ◽

Air Bubble ◽

Whiteleg Shrimp ◽

Bubble Curtain

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Studies on Fish Behaviour Control by Air Bubble Curtain II. Fish Herding Effect by Air Bubble Curtain in a Large Circular Tank.

NIPPON SUISAN GAKKAISHI ◽

10.2331/suisan.58.45 ◽

1992 ◽

Vol 58 (1) ◽

pp. 45-48 ◽

Cited By ~ 1

Author(s):

Seiji Akiyama ◽

Takafumi Arimoto ◽

Makoto Inoue

Keyword(s):

Fish Behaviour ◽

Air Bubble ◽

Bubble Curtain

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Experimental and Numerical Investigations of Bubble Dynamics in Porous and Non-Porous Media

Volume 10: Petroleum Technology ◽

10.1115/omae2015-42257 ◽

2015 ◽

Author(s):

M. A. Rahman ◽

S. Butt ◽

J. M. Alam ◽

M. Shahwan ◽

M. Hunt ◽

...

Keyword(s):

Porous Media ◽

Bubble Dynamics ◽

Cfd Simulation ◽

Viscous Fluids ◽

Experimental Results ◽

Axial Distance ◽

Stagnant Water ◽

Bubble Rise ◽

Air Bubble ◽

Bubble Rising

In this study an experimental work is conducted to investigate the shape and speed of an air bubble in a pipe filled with different viscous fluids and porous media. The experimental results are also compared with the Computational Fluid Dynamics (CFD) simulation. Multiphase flows are complex due to the infinitely deformable nature of interface in gas/liquid flows. If one of the phases is gas acts as dispersed phase in the form of bubble, then the complexity will arise from the non-uniform distribution of bubbles in the pipe cross-section and axial distance. Inclusion of different viscous fluids simulating the industrial scale hydrocarbon properties brings added challenge in understating the bubble rise, coalescence and breakup dynamics. Moreover, bubble rise and change of shape of bubble in porous media will bring additional complexity in the flow dynamics. The pipe used in the experiment and CFD was 11.6 cm ID and a length of 100 cm. Three situations were tested: i) an air bubble rising in stagnant water, ii) an air bubble rising in moving water, and iii) an air bubble rising in a stagnant water but filled with porous media with porosity of 27%. Preliminary CFD results indicate that an air bubble has an average velocity of 0.2468 m/s and 0.2524 m/s in stagnant water and moving water, respectively, which is very close to experimental results.

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Study of the Sound Escape with the Use of an Air Bubble Curtain in Offshore Pile Driving

Journal of Marine Science and Engineering ◽

10.3390/jmse9020232 ◽

2021 ◽

Vol 9 (2) ◽

pp. 232

Author(s):

Yaxi Peng ◽

Apostolos Tsouvalas ◽

Tasos Stampoultzoglou ◽

Andrei Metrikine

Keyword(s):

Noise Reduction ◽

Wave Field ◽

Ecological Impact ◽

Free Field ◽

Pile Driving ◽

Noise Prediction ◽

Underwater Noise ◽

Air Bubble ◽

Noise Transmission ◽

Bubble Curtain

Underwater noise pollution generated by offshore pile driving has raised serious concerns over the ecological impact on marine life. To comply with the strict governmental regulations on the threshold levels of underwater noise, bubble curtains are usually applied in practice. This paper examines the effectiveness of an air bubble curtain system in noise reduction for offshore pile driving. The focus is placed on the evaluation of noise transmission paths, which are essential for the effective blockage of sound propagation. A coupled two-step approach for the prediction of underwater noise is adopted, which allows us to treat the waterborne and soilborne noise transmission paths separately. The complete model consists of two modules: a noise prediction module for offshore pile driving aiming at the generation and propagation of the wave field and a noise reduction module for predicting the transmission loss in passing through an air bubble curtain. With the proposed model, underwater noise prognosis is examined in the following cases: (i) free-field noise prediction without the air bubble curtain, (ii) waterborne path fully blocked at the position of the air bubble curtain while the rest of the wave field is propagated at the target distance, (iii) similarly to (ii) but with a non-fully blocked waterborne path close to the seabed, and (iv) air bubble curtain modeled explicitly using an effective medium theory. The results provide a clear indication of the amount of energy that can be channeled through the seabed and through possible gaps in the water column adjacent to the seabed. The model allows for a large number of simulations and for a thorough parametric study of the noise escape when a bubble curtain is applied offshore.

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