In this paper, we present a simple spring-block model for ocean internal waves based on the self-organized criticality （SOC）. The oscillations of the water blocks in the model display power-law behavior with an expo...In this paper, we present a simple spring-block model for ocean internal waves based on the self-organized criticality （SOC）. The oscillations of the water blocks in the model display power-law behavior with an exponent of -2 in the frequency domain, which is similar to the current and sea water temperature spectra in the actual ocean and the universal Garrett and Munk deep ocean internal wave model [Geophysical Fluid Dynamics 2 （1972） 225; J. Geophys. Res. 80 （1975） 291]. The influence of the ratio of the driving force to the spring coefficient to SOC behaviors in the model is also discussed.展开更多
In an atrocious ocean environment,the lateral propulsion hole could potentially be partly out of water and capture an air cavity.Bubbles would form when the captured air cavity escapes underwater and they may affect t...In an atrocious ocean environment,the lateral propulsion hole could potentially be partly out of water and capture an air cavity.Bubbles would form when the captured air cavity escapes underwater and they may affect the performance of the sonar.The common commercial computational fluid dynamics software CFX was adopted to calculate the ambient flow field around the lateral propulsion hole generated by a moving vessel.The oscillation of the spherical bubble was based on the Rayleigh-Plesset equation and its migration was modeled using the momentum equation.The radiated noise of the oscillating bubble was also studied.The aim is that the results from this paper would provide some insight into corresponding fluid and acoustic study.展开更多
This paper is to investigate a variable-coefficient modified Kortweg-de Vries （vc-mKdV） model, which describes some situations from fluid mechanics, ocean dynamics, and plasma mechanics. By the AblowRz-Kaup-NewellSe...This paper is to investigate a variable-coefficient modified Kortweg-de Vries （vc-mKdV） model, which describes some situations from fluid mechanics, ocean dynamics, and plasma mechanics. By the AblowRz-Kaup-NewellSegur procedure and symbolic computation, the Lax pair of the vc-MKdV model is derived. Then, based on the aforementioned Lax pair, the Darboux transformation is constructed and a new one-soliton-like solution is obtained as weft Features of the one-soliton-like solution are analyzed and graphically discussed to illustrate the influence of the variable coefficients in the solitonlike propagation.展开更多
The marine medium-speed diesel engines are started by two methods;one is the electric motors,and the other air starting motors.Even though air starting motor is dependent of the engine types and sizes,it has been wide...The marine medium-speed diesel engines are started by two methods;one is the electric motors,and the other air starting motors.Even though air starting motor is dependent of the engine types and sizes,it has been widely used in this area due to its simplicity,convenience and reliability.The purpose of this paper is to give the designing parameters in order to make a proper "Air Starting Motor" using CFD.The aerodynamic approaches were given to understand the internal flow characteristics of the air starting motor.In addition,we have carried out the investigation of effects of tip clearance.In the calculations the tip clearance of air starting motor has been varied between 0,2.8,4.3 and 5.7% of blade span.The results of computation are the tip clearance increased to 2.8%,the torque decreased 24%,and there was no more large changes when the clearances increased to 4.3% and 5.7%.展开更多
We briefly review the recent progress in marine hydrodynamics.Developments in wave-structure interaction,wave-current interaction,Rogue waves,sloshing in liquid tanks and their applications in ocean engineering,such a...We briefly review the recent progress in marine hydrodynamics.Developments in wave-structure interaction,wave-current interaction,Rogue waves,sloshing in liquid tanks and their applications in ocean engineering,such as Floating Production Storage and Offloading facility(FPSO) and Very Large Floating Structure(VLFS),are presented.展开更多
基金supported by the Key Project of National Natural Science Foundation of China under Grant No.40730842the Knowledge Innovation Program of the Chinese Academy of Sciences under Grant No.KZCX2-YW-201the Postdoctoral Special Fund for the Innovation Program of the Shandong Province
文摘In this paper, we present a simple spring-block model for ocean internal waves based on the self-organized criticality （SOC）. The oscillations of the water blocks in the model display power-law behavior with an exponent of -2 in the frequency domain, which is similar to the current and sea water temperature spectra in the actual ocean and the universal Garrett and Munk deep ocean internal wave model [Geophysical Fluid Dynamics 2 （1972） 225; J. Geophys. Res. 80 （1975） 291]. The influence of the ratio of the driving force to the spring coefficient to SOC behaviors in the model is also discussed.
基金Supported by the National Science Foundation of China （11002038）Key Project of National Natural Science Funds （50939002）+2 种基金National Defense Foundation Scientific Project （B2420110011）the National Science Foundation for Young Scientists of China （51009035）Natural Science Funds of Heilongjiang Province （E201047,A200901）
文摘In an atrocious ocean environment,the lateral propulsion hole could potentially be partly out of water and capture an air cavity.Bubbles would form when the captured air cavity escapes underwater and they may affect the performance of the sonar.The common commercial computational fluid dynamics software CFX was adopted to calculate the ambient flow field around the lateral propulsion hole generated by a moving vessel.The oscillation of the spherical bubble was based on the Rayleigh-Plesset equation and its migration was modeled using the momentum equation.The radiated noise of the oscillating bubble was also studied.The aim is that the results from this paper would provide some insight into corresponding fluid and acoustic study.
基金Supported by the National Natural Science Foundation of China under Grant No. 60772023by the Open Fund of the State Key Laboratory of Software Development Environment under Grant No. BUAA-SKLSDE-09KF-04+1 种基金Beijing University of Aeronautics and Astronautics, by the National Basic Research Program of China (973 Program) under Grant No. 2005CB321901by the Specialized Research Fund for the Doctoral Program of Higher Education under Grant Nos. 20060006024 and 200800130006, Chinese Ministry of Education
文摘This paper is to investigate a variable-coefficient modified Kortweg-de Vries （vc-mKdV） model, which describes some situations from fluid mechanics, ocean dynamics, and plasma mechanics. By the AblowRz-Kaup-NewellSegur procedure and symbolic computation, the Lax pair of the vc-MKdV model is derived. Then, based on the aforementioned Lax pair, the Darboux transformation is constructed and a new one-soliton-like solution is obtained as weft Features of the one-soliton-like solution are analyzed and graphically discussed to illustrate the influence of the variable coefficients in the solitonlike propagation.
基金supported by the Post BK21 project of Ministry of Education,Science & Technology,and National Research Lab.of Korea Research Foundation of Korea (R0A-2008-000-20069-0)
文摘The marine medium-speed diesel engines are started by two methods;one is the electric motors,and the other air starting motors.Even though air starting motor is dependent of the engine types and sizes,it has been widely used in this area due to its simplicity,convenience and reliability.The purpose of this paper is to give the designing parameters in order to make a proper "Air Starting Motor" using CFD.The aerodynamic approaches were given to understand the internal flow characteristics of the air starting motor.In addition,we have carried out the investigation of effects of tip clearance.In the calculations the tip clearance of air starting motor has been varied between 0,2.8,4.3 and 5.7% of blade span.The results of computation are the tip clearance increased to 2.8%,the torque decreased 24%,and there was no more large changes when the clearances increased to 4.3% and 5.7%.
文摘We briefly review the recent progress in marine hydrodynamics.Developments in wave-structure interaction,wave-current interaction,Rogue waves,sloshing in liquid tanks and their applications in ocean engineering,such as Floating Production Storage and Offloading facility(FPSO) and Very Large Floating Structure(VLFS),are presented.
