Experimental Research and Modeling of the Underwater Sound in Marine Environment

2013 ◽  
Vol 430 ◽  
pp. 285-289 ◽  
Author(s):  
Delicia Arsene ◽  
Claudia Borda ◽  
Larisa Butu ◽  
Marinela Marinescu ◽  
Victor Popovici ◽  
...  
Keyword(s):  
Acoustic Field ◽  
Measuring System ◽  
The Black Sea ◽  
Underwater Sound ◽  
Dynamic Measurements ◽  
Marine Habitat ◽  
Data Measurement ◽  
Impact Area ◽  
Measurement Methodology ◽  
Acoustic Impact

The paper presents a modeling of the acoustic field emitted by a rig tender located offshore exploration in the Black Sea. Are presented measuring system, experimental context, the types of noise that participate in the overall noise budget and the conditions in which measurements were made, also are mentioned and the project established through were measured the parameters and were defined devices which these measurements were made. Measurement system used is adaptable, allowing dynamic measurements and operative analysis of the acquired data. Measurement methodology was determined by an acoustic project, which was set to be purchased both: sizes and ways of interpreting them. Modeling acoustic field shows that the maximum acoustic impact area, below 120 dB re 1μPa criterion (proposed and accepted by Marine Directive) was extended to 3-5Km distance around the ship. It is expected to produce adverse effects on the marine habitat and on the underwater life.

Ship Ballast Water Management in Turkish Ports and Waterways

2011 ◽  
Vol 45 (2) ◽  
pp. 23-32
Author(s):  
Tanzer Satir ◽  
Bhaskar Kura
Keyword(s):  
Water Management ◽  
Ballast Water ◽  
Structural Integrity ◽  
Marine Pollution ◽  
The Black Sea ◽  
Marine Habitat ◽  
Efficient Operation ◽  
Western Asia ◽  
Ship Ballast Water ◽  
Ballast Water Management

AbstractThe introduction of invasive marine species into a new environment by ballast water attached to ship hulls has been identified as one of the four greatest threats to the world’s oceans. The other three are land-based sources of marine pollution, overexploitation of living marine resources, and physical alteration/destruction of marine habitat. Ballast is any material used to add weight to balance an object. One example includes the sandbags carried on conventional hot air balloons, which can be discarded to lighten the balloon’s load, allowing it to ascend. Ballast water is water carried by ships to ensure stability, trim, and structural integrity. Shipping moves over 80% of the world’s commodities and transfers approximately 3‐5 billion tons of ballast water internationally each year. A similar volume may also be transferred domestically within countries and regions each year. Ballast water is absolutely essential to the safe and efficient operation of modern shipping, providing balance and stability to unladen ships. However, it may also pose a serious ecological, economical, and health threat to the marine environment.Turkey is a Eurasian country that stretches across the Anatolian peninsula in western Asia and southeastern Europe. Turkey is surrounded by three seas: the Mediterranean Sea, the Black Sea, and the Aegean Sea. The Turkish straits that separate Europe and Asia are one of the busiest waterways of the world. Turkey has several ports and berthing facilities. The number of ships coming to ports or passing through the straits has been increasing in the last decade. Half of these ships are carrying ballast water. Turkey has not ratified the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM) as yet but will soon prepare ballast water strategies. This paper discusses two different topics: ship ballast water management strategies and treatment technologies. The authors recommend the best strategies for prevention of ship ballast water pollution in the Turkish straits and ports.

Approximating acoustic field uncertainty in underwater sound channels

2006 ◽  
Vol 119 (5) ◽  
pp. 3353-3353 ◽  
Author(s):  
Kevin R. James ◽  
David R. Dowling
Keyword(s):  
Acoustic Field ◽  
Underwater Sound

Thermal processes during acoustic impact on a liquid-saturated porous

2019 ◽  
Author(s):  
Г.Я. Хусаинова
Keyword(s):  
Porous Medium ◽  
Acoustic Field ◽  
Traveling Wave Solutions ◽  
Pressure Waves ◽  
Oil Well ◽  
Wave Problem ◽  
Temperature Problem ◽  
Acoustic Impact ◽  
The Right ◽  
The Impact

Выполнено исследование процесса нагрева трехзонной пористой среды, насыщенной жидкостью, с помощью акустического поля. С учетом того, что основным механизмом, переводящим энергию акустического поля в тепло, является сила вязкого трения между насыщающей жидкостью и скелетом пористой среды, построена функция объемного источника тепла для процесса нагрева пористой среды акустическим воздействием. Исследована зависимость температурного поля от параметров пористой среды и акустического поля. Research of the impact of acoustic field on the near-well zone of rocks is considered to be attractive for using in different technological processes, in particular, during gas-oil well exploitation. Thermal effect under acoustic impact on three-zone porous medium is analyzed in this paper. At the boundary of the porous medium a source of harmonic pressure waves is imposed. Affected by a source of pressure waves liquid will vibrate relatively to the skeleton of the porous medium. The wave and the thermal problem are considered. The linearized equations of continuity, momentum and state, as well as boundary conditions are written for the wave problem. For the boundary between the first and second zones we write the conditions of absence of an abrupt change in the pressure and the velocity of motion of the liquid, and the right-hand boundary of the second zone is considered to be highly permeable. The solution of the wave problem is sought in the form of a traveling wave. Solutions are obtained for the pressure and velocity of fluid flow the formula for calculating the average heat influx per unit volume in a unit time. For the temperature problem we write the equation of the influx of heat to the porous medium saturated with liquid, with allowance for the heat source due to the viscous attenuation of the acoustic field. The temperature problem is solved numerically by the sweep method. The dependence of the temperature field from the porous medium parameters and the acoustic field has been analyzed. Graphs of the dependence of the temperature of the porous medium from the coordinates are presented. The obtained results show that by selecting the frequency and amplitude of the acoustic field, it is possible to achieve a pronounced effect on the clogged areas of the bottomhole formation zone in order to heat this zone and, thereby, melting and cleaning from paraffin deposits.

Mathematical Modeling Of Radio-Frequency Electromagnetic And Acoustic Impact On Formation In Combination With Solvent Injection

2015 ◽  
Vol 10 (3) ◽  
pp. 89-96
Author(s):  
Gulnara Izmaylova ◽  
Liana Kovaleva ◽  
Nur Nasyrov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Radio Frequency ◽  
Acoustic Field ◽  
High Viscosity ◽  
Oil Reservoir ◽  
Rf Heating ◽  
Low Viscosity ◽  
Acoustic Impact ◽  
High Viscosity Oil

We investigate the possibility of increasing the efficiency of extraction of high-viscosity oil combined effect of radio-frequency (RF) electromagnetic (EM) and acoustic fields on the formation and miscible displacement oil solvent. A mathematical model of two-stage impact on the oil reservoir. At the 1st stage, the heating of the formation RF electromagnetic and acoustic field. At the 2nd stage the RF heating of the formation with simultaneous injection of low-viscosity solvent.

scholarly journals Experimental Study on the Impact Characteristics of Cavitation Bubble Collapse on a Wall

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1262 ◽  
Author(s):  
Jing Luo ◽  
Weilin Xu ◽  
Jun Deng ◽  
Yanwei Zhai ◽  
Qi Zhang
Keyword(s):  
Impact Strength ◽  
Cavitation Bubble ◽  
Measuring System ◽  
Critical Conditions ◽  
Bubble Collapse ◽  
Main Concern ◽  
Wall Surface ◽  
Cavitation Bubbles ◽  
Impact Area ◽  
The Impact

As a hydrodynamic phenomenon, cavitation is a main concern in many industries such as water conservancy, the chemical industry and medical care. There are many studies on the generation, development and collapse of cavitation bubbles, but there are few studies on the variation of the cyclic impact strength on walls from the collapse of cavitation bubbles. In this paper, a high-speed dynamic acquisition and analysis system and a pressure measuring system are combined to study the impact of a cavitation bubble generated near a wall for various distances between the cavitation bubble and the wall. The results show that (1) with the discriminating criteria of the impact pressure borne by the wall, the critical conditions for the generation of a micro-jet in the collapse process of the cavitation bubbles are obtained, and therefore collapses of cavitation bubbles near the wall are mainly divided into primary impact area collapses, secondary impact area collapses and slow release area collapses; (2) it can be seen from the impact strength of the cavitation bubble collapse on the wall surface that the impact of cavitation bubbles on the wall surface during the first collapse decreases as γ (the dimensionless distance between the cavitation bubble and the wall) increases, but the impact of the second collapse on the wall surface increases first and then decreases sharply. When γ is less than 1.33, the impact on the wall surface is mainly from the first collapse. When γ is between 1.33 and 2.37, the impact on the wall surface is mainly from the second collapse. These conclusions have potential theoretical value for the utilization or prevention and control technologies for cavitation erosion.

scholarly journals New considerations regarding underwater noise in Black Sea

2018 ◽  
Vol XIX (1) ◽  
pp. 381-392
Author(s):  
Pricop M
Keyword(s):  
Black Sea ◽  
Sea Water ◽  
Coherence Function ◽  
Measurement Techniques ◽  
Measuring System ◽  
The Black Sea ◽  
Shallow Waters ◽  
Underwater Noise ◽  
Noise Sources ◽  
Acoustic Signature

The development and standardization of measurement techniques for underwater noise sources are important to both military and civil fields regarding the reduction of sound emitted by commercial and military ships. This paper presents new analysis of the acoustic signature of a small vessel during a voyage in the Black Sea. The measurements were made when the ship was moored in shallow waters. The measuring system had 3 hydrophones that were positioned at different depths. Using the coherence function, it was determined the correlation between the recordings. The results were analysed to determine the acoustic signature of the ship. Thermal variations of sea water and effects of sound reflection from the bottom of the sea were taken into account. Conclusions have been made regarding the utility of this type of analysis and the levels of underwater noise in the shallow waters of the Black Sea.

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