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Numerical simulation of hull/propeller interaction of submarine in submergence and near surface conditions

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Journal of Hydrodynamics 2014年第1期26卷 50-56页

作者：张楠张胜利 China Ship Scientific Research Center

Hull/propeller interaction is of great importance for powering performance prediction. The features of hull/propeller interaction of a submarine model with a high-skew five blade propeller in submergence and near surface conditions are numerically simulated. The effect of propeller rotation is simulated by the sliding mesh technique. Free surface is captured by the volume of fluid （VOF） method. Computed results including resistance, thrust, torque and self-propulsion factor are compared with experimental data. It shows fairly good agreement. The resistance and wave pattern of the model at different depths of submergence are computed. And the thrust, torque and self-propulsion factor of the model in submergence and near surface condition are compared to analyze the effect of free surface on self-propulsion performance. The results indicate that free surface has more influence on resistance than that on self-propulsion factors.

关键词： submarine hull/propeller interaction numerical simulation sliding mesh volume of fluid （VOF） method

An integrated optimization design of a fishing ship hullform at different speeds

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Journal of Hydrodynamics 2018年第6期30卷 1174-1181页

作者：杨磊李胜忠赵峰倪其军 China Ship Scientific Research Center Wuxi 217082China

This paper shows how to improve the hydrodynamics performance of a ship by solving a shape optimization design problem at different speeds using the simulation-based design(SBD) technique. The SBD technique is implemented by integrating the advanced CFD codes, the global optimization algorithms and the geometry modification methods, which offers a new way for the hullform optimization design and the configuration innovation. The multiple speed integrated optimization for the hullform design is a challenge. In this paper, an example of the technique application for a fishing ship hullform optimization at different speeds is demonstrated. In this optimization process, the free-form deformation method is applied to automatically modify the geometry of the ship, and the multi-objective particle swarm optimization(MOPSO) algorithm is adopted for exploring the design space. Two objective functions, the total resistances at two different speeds(12 kn and 14 kn) are assessed by the RANS solvers. The optimization results show that the decrease of the total resistance is significant after the optimization at the two speeds, with a reduction of 5.0% and 11.2%, respectively. Finally, dedicated experimental validations for the design model and the optimized model are carried out for the computation and the optimization processes. At the two speeds, the reduction of the total resistance in the model scale is about 6.0% and 11.8% after the optimization. It is a valuable result in view of the small modifications allowed and the good initial performances of the original model. The given practical example demonstrates the feasibility and the superiority of the proposed SBD technique for the multiple speed integrated optimization.

关键词： Hullform design optimization simulation-based design (SBD) techniques multiple speeds optimization CFD techniques total resistance

The application of three-dimensional hydroelastic analysis of ship structures in Pekeris hydro-acoustic waveguide environment

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Acta Mechanica Sinica 2014年第1期30卷 59-66页

作者： Ming-Song Zou You-Sheng Wu Yan-Min Liu China Ship Scientific Research Center

The hydroelastic analysis and sonoelastic analysis methods are incorporated with the Green＇s function of the Pekeris ocean hydro-acoustic waveguide model to produce a three-dimensional sonoelastic analysis method for ships in the ocean hydro-acoustic environment. The seabed condition is represented by a penetrable boundary of prescribed density and sound speed. This method is employed in this paper to predict the vibration and acoustic radiation of a 1 500 t Small Water Area Twin Hull （SWATH） ship in shallow sea acoustic environment. The wet resonant frequencies and radiation sound source levels are predicted and compared with the measured results of the ship in trial.

关键词： Hydroelasticity Sonoelasticity Acousticwaves Shallow sea Free surface effect Seabed effect -SWATH ship

A NEW LARGE CAVITATION CHANNEL IN China Ship Scientific Research Center

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Journal of Hydrodynamics 2003年第4期15卷 59-62页

作者： Wang Tian-kui, Lu Fang, Fan Xiao-bing, Shi Xiao-jun China Ship Scientific Research Center, Wuxi 214082, china china ship Sci. Res. Ctr. Wuxi 214082 China

After about 10 years' runing of the LCC (DTRC, USA) and the HYKAT( HSVA,Germany) , another new large cavitation channel with low background noise is to be in operation inChina Ship Scientific Research Center(CSS-RC), Wuxi, china. The important specific properties of thechannel are the large test section (2. 0 m in height, 2. 2 m in width and 10. 5 m in length) , themaximum speed of more than 15 m/s, the low turbulence level, the low background noise of the wholefacility, together with the new noise measurement system. So large scale models can be tested withonly minor wall effects and at high Renolds numbers, and the pretentious acoustical measurements canbe performed. This paper describes the features of the new channel and the first test resultsobtained during extensive calibration and validation.

关键词： large cavitation channel cavitation test noise investigation

Resistance Spot Welding Method for Metal-Based Fiber Bragg Grating Sensors

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Transactions of Nanjing University of Aeronautics and Astronautics 2015年第3期32卷 289-296页

作者：张涛韦朋余岳亚霖 China Ship Scientific Research Center

Aiming at the requirements of installation and work environment of metal-based fiber Bragg grating(FBG)sensor,a resistance spot welding method is presented.Firstly,the effect of welding parameters on welding quality is discussed theoretically,and a suitable resistance spot welding method for the metal-based FBG sensor is proposed for the first time.Then through serial resistance spot welding tests,the feasibility and practicability of the method are verified,and optimal welding parameters for two different tested metals are obtained.Fatigue performance test validates FBG sensors installed by the proposed method with good fatigue properties and long-term stable measurement performance.The research results can provide technical guidance for engineering structure long-term safety monitoring.

关键词： fiber Bragg grating(FBG)sensor resistance spot wel

Efficient suction control of unsteadiness of turbulent wing-plate junction flows

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Journal of Hydrodynamics 2017年第2期29卷 353-360页

作者：刘建华宋长友 China Ship Scientific Research Center Wuxi 214082China

A wing-body junction flow of a navigating underwater vehicle is considered to be a crucial source of the flow radiating acoustic noise, which attracts much research interest. In this paper, wing-plate junction flows are experimentally investigated in a low-speed wind tunnel by smoke-wire flow visualizations and time-resolved PIV measurements. To reveal the physical behavior of such flows, smoke-wire flow visualizations are conducted for a laminar wing-plate junction. A novel control strategy is proposed, to accurately locate the suction openings where the streamline is about to roll up to form a vortex in the turbulent junction flows. The control effect is discussed in perspectives of both the time-averaged and instantaneous flow fields.

关键词： Wing-plate junction flow horseshoe vortex turbulence unsteadiness PIV

A three-dimensional hydroelasticity theory for ship structures in acoustic field of shallow sea

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Journal of Hydrodynamics 2013年第6期25卷 929-937页

作者：邹明松吴有生刘艳敏林长刚 China Ship Scientific Research Center

Nowadays the development of green ship technology requires the vibration and noise control of oceangoing ships. The three-dimensional hydroelasticity theory of ships was previously extended to include the effect of fluid compressibility. This enables the dynamic responses and the acoustic radiations of a ship excited by onboard machineries or fluid fluctuation loads to be predicted. In this paper the hydroelastic analysis and sonoelastic analysis methods are fixrther incorporated with the Green＇s function in the Pekeris ocean hydro-acoustic waveguide model to work out a three-dimensional sonoelastic analysis method for ships in the ocean hydro-acoustic environment. As examples, the sound radiations of a floating elastic spherical shell excited by a concentrated force and a traveling LNG ship excited by the propeller induced pulsating forces acting on the wetted bottom plate of the stem in the shallow sea environment are predicted. The influences of the free surface and the sea bed on the generalized hydrodynamic coefficients and the acoustic pressure distributions in fluid domain are illustrated and discussed.

关键词： hydroelasticity sonoelasticity acoustic waves shallow sea environment LNG ship

An experimental study on the impact behavior of cavitation inside tip clearance of a hydrofoil

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Journal of Hydrodynamics 2023年第6期35卷 1208-1214页

作者： Yan-tao Cao Liang-hao Xu Xiao-xing Peng National Key Laboratory on ship Vibration and Noise China Ship Scientific Research CenterWuxi214082China Taihu Laboratory of Deepsea Technological Science Wuxi214082China

Tip clearance cavitation is one of the most common cavitation phenomena exist on duct propellers,pumps and some hydraulic turbines,which may lead to erosion of the components.Due to the influence of the nearby wall,cavitation inside the tip clearance is more complicated than other cases without interaction.So far,the understanding about the impact mechanism of tip clearance cavitation is still limited.In this paper,to obtain the impact behavior of tip clearance cavitation,a high-speed camera was used to capture the cavitation behavior inside the tip clearance of a hydrofoil,and surface paint coating peeling method was applied to show the impact region.Results indicated that cavitation around the tip of the hydrofoil was composed of a tip separation cavity and a tip leakage vortex cavity,and the one with contribution to impact was the tip separation cavity.Through the comprehensive analysis of the paint peeling region and dynamic behavior of tip separation cavity,the impact was found to be related to the local collapse and rebound of the cloud cavitation shed from the attached part.In addition,the influence of tip clearance size on the behavior of tip clearance cavitation was also investigated.As the tip clearance size increased,the tip separation cavity tended to transfer from sheet cavitation to vortex cavitation.These findings can provide a sound basis for evaluating the erosion risk arising from the tip clearance cavitation.

关键词： Tip clearance cavitation impact region impact behavior tip clearance size

Theory and applications of coupled fluid-structure interactions of ships in waves and ocean acoustic environment

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Journal of Hydrodynamics 2016年第6期28卷 923-936页

作者：吴有生邹明松田超司马灿祁立波丁军李志伟陆晔 China Ship Scientific Research Center Wuxi 214082 China

Wave induced motions and structural distortions, and machinery or propeller excited vibrations and acoustic radiations of a ship are two kinds of important fluid-structure interaction problems. The branch of ship science that describes the coupled wave induced dynamic behavior of fluid-structure interaction system is referred to as hydroelasticity. During the past three decades the development of three-dimensional hydroelasticity theories and applications gained great progress. Recently the 3-D hydroelasticity theory was further extended to account for the fluid compressibility and the effect of the ocean acoustic environment with finite water depth. A three-dimensional sono-elasticity theory was then produced. In this paper, the 3-D hydroelasticity theory and the 3-D sono-elasticity theory of ships are briefly described. To illustrate the applicability and feasibility of these theories and the corre- sponding numerical approaches, several examples are presented including the predictions of wave loads, rigid-body and flexible- body responses, springing and fatigue behaviors, machinery or propeller excited coupled structural vibrations and acoustic radiations, as well as design optimizations for improving safety and acoustic behaviors of ships.

关键词： hydroelasticity sono-elasticity wave load structural strength springing vibration acoustic radiation