A FPED （flexible piezoelectric device） composed of PVDF （polyvinylidene fluoride） and functional resin has been developed to generate electric power from wind energy with wide range in frequency. It was cleared th...A FPED （flexible piezoelectric device） composed of PVDF （polyvinylidene fluoride） and functional resin has been developed to generate electric power from wind energy with wide range in frequency. It was cleared that electrical characteristics of the FPED generated by wind power and availability of an attached bluff body in uniform wind. Moreover, electric performance of the FPED which is laminated with a stretching resin and has a roughness surface such as woolen and small hemisphere, was validated. It was shown that both a force caused by breeze and wind energy with wide range of spectrum could be harvested effectively using the FPED.展开更多
Hydroelasticity caused by water impact is of concem in many applications of ocean engineering/naval architect and is a complicated physical phenomenon. The authors have developed a coupled Eulerian scheme with Lagrang...Hydroelasticity caused by water impact is of concem in many applications of ocean engineering/naval architect and is a complicated physical phenomenon. The authors have developed a coupled Eulerian scheme with Lagrangian particles to combine advantages and to compensate disadvantages in both grid based method and particle based method. In this study, the developed numerical model was applied to hydroelastic problems due to impact pressure such as water entry of an elastic cylinder and elastic tanker motion in wave. The authors showed the numerical results which is overall agreement with experimental results. The proposed numerical scheme can be useful and effectiveness to evaluate hydroelasticity and ship-wave interaction in nonlinear wave motion with breaking.展开更多
Capable and accurate predictions of some effects of strongly nonlinear interaction wave-ship associated with hydroelastic behaviors are very required for simulation tool in naval architect and ocean engineering. It ca...Capable and accurate predictions of some effects of strongly nonlinear interaction wave-ship associated with hydroelastic behaviors are very required for simulation tool in naval architect and ocean engineering. It can guarantee ship safety at the sea state by producing proper design. Therefore, we have developed a hybrid scheme based on both grid and particle method. In order to clarify hydroelastic behaviors of a ship, a dropping test of a ship with elastic motion has been performed firstly. The developed scheme has been then validated on ship dropping case under the same conditions with experiment. The comparisons showed consistently in good agreement. Furthermore, evaluation on hydroelastic behaviors of ship motion under slamming, the impact pressure tends to increase in increasing Froude number. （Fn） The bending moment and torque defined at the centre gravity due to hogging and sagging events can be predicted well, and their effects on the ship increase in increasing wave length even though the impact pressure decreases in increasing wave length after wave length λ/L, where L is ship length, is equal to 1.0. Moreover, hydroelastie behaviors affect the large heave and pitch amplitudes. Finally, the developed scheme can predict simultaneously hydrodynamic and hydroelastic with a strongly nonlinear interaction between wave and ship.展开更多
文摘A FPED （flexible piezoelectric device） composed of PVDF （polyvinylidene fluoride） and functional resin has been developed to generate electric power from wind energy with wide range in frequency. It was cleared that electrical characteristics of the FPED generated by wind power and availability of an attached bluff body in uniform wind. Moreover, electric performance of the FPED which is laminated with a stretching resin and has a roughness surface such as woolen and small hemisphere, was validated. It was shown that both a force caused by breeze and wind energy with wide range of spectrum could be harvested effectively using the FPED.
文摘Hydroelasticity caused by water impact is of concem in many applications of ocean engineering/naval architect and is a complicated physical phenomenon. The authors have developed a coupled Eulerian scheme with Lagrangian particles to combine advantages and to compensate disadvantages in both grid based method and particle based method. In this study, the developed numerical model was applied to hydroelastic problems due to impact pressure such as water entry of an elastic cylinder and elastic tanker motion in wave. The authors showed the numerical results which is overall agreement with experimental results. The proposed numerical scheme can be useful and effectiveness to evaluate hydroelasticity and ship-wave interaction in nonlinear wave motion with breaking.
文摘Capable and accurate predictions of some effects of strongly nonlinear interaction wave-ship associated with hydroelastic behaviors are very required for simulation tool in naval architect and ocean engineering. It can guarantee ship safety at the sea state by producing proper design. Therefore, we have developed a hybrid scheme based on both grid and particle method. In order to clarify hydroelastic behaviors of a ship, a dropping test of a ship with elastic motion has been performed firstly. The developed scheme has been then validated on ship dropping case under the same conditions with experiment. The comparisons showed consistently in good agreement. Furthermore, evaluation on hydroelastic behaviors of ship motion under slamming, the impact pressure tends to increase in increasing Froude number. （Fn） The bending moment and torque defined at the centre gravity due to hogging and sagging events can be predicted well, and their effects on the ship increase in increasing wave length even though the impact pressure decreases in increasing wave length after wave length λ/L, where L is ship length, is equal to 1.0. Moreover, hydroelastie behaviors affect the large heave and pitch amplitudes. Finally, the developed scheme can predict simultaneously hydrodynamic and hydroelastic with a strongly nonlinear interaction between wave and ship.
