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 scie...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.展开更多
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 fl...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.展开更多
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...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.展开更多
According to the Price-Wu condition at interface between flexible marine structure and surrounding fluid flow, a solution for the 3-D potential flow in time domain around a flexible structure traveling in waves has be...According to the Price-Wu condition at interface between flexible marine structure and surrounding fluid flow, a solution for the 3-D potential flow in time domain around a flexible structure traveling in waves has been expressed with a boundary integral equation. The Green function, which satisfied the linearized free surface condition for the time-dependent problem was employed. A hydroelastic analysis directly in time domain to predict the loads, motions and structural responses of ships at a steady forward speed in a seaway was formulation. The numerical results given by present method were compared with the experimental measurements, and the prediction provided by the 3-D hydroelasticity theory in frequency domain.展开更多
基金supported by the Ministry of Science and Technology with the research project (Grant No. 2013CB36102)the Ministry of Industry and Information Technology with the research project in the fields of high-tech ships
文摘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.
文摘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.
文摘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.
文摘According to the Price-Wu condition at interface between flexible marine structure and surrounding fluid flow, a solution for the 3-D potential flow in time domain around a flexible structure traveling in waves has been expressed with a boundary integral equation. The Green function, which satisfied the linearized free surface condition for the time-dependent problem was employed. A hydroelastic analysis directly in time domain to predict the loads, motions and structural responses of ships at a steady forward speed in a seaway was formulation. The numerical results given by present method were compared with the experimental measurements, and the prediction provided by the 3-D hydroelasticity theory in frequency domain.
