The purpose of this paper is to investigate the instantaneous properties of wave slamming on the plate structure of an open structure.The advanced instantaneous measuring technique-Particle Image Velocimetry(PIV) is a...The purpose of this paper is to investigate the instantaneous properties of wave slamming on the plate structure of an open structure.The advanced instantaneous measuring technique-Particle Image Velocimetry(PIV) is applied to acquire the instantaneous velocity field of wave slamming.From the cross-correlation analysis results of the images captured by the CCD camera,the flow fields of wave impacting on the structure are displayed visually,and the instantaneous whole-field fluid velocity vectors are obtained.The relation between the instantaneous peak impacting pressures and the instantaneous velocities of water particles is studied by probability analysis.展开更多
A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid(VOF)method.An active absorbing wave-maker based on linear wave theory is set on the left boundary of...A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid(VOF)method.An active absorbing wave-maker based on linear wave theory is set on the left boundary of the wave flume.The progressive waves and the absorbing waves are generated simultaneously at the active wave generating-absorbing boundary.The absorbing waves are generated to eliminate the waves coming back to the generating boundary due to reflection from the outflow boundary and the structures.SIRW method proposed by Frigaard and Brorsen(1995)is used to separate the incident waves and reflected waves.The digital filters are designed based on the surface elevation signals of the two wave gauges.The corrected velocity of the wave-maker paddle is the output from the digital filter in real time.The numerical results of regular and irregular waves by the active absorbing-generating boundary are compared with the numerical results by the ordinary generating boundary to verify the performance of the active absorbing-generator boundary.The differences between the initial incident waves and the estimated incident waves are analyzed.展开更多
The superstructures of marine structures supported by the elastic legs and located in the splash zone will subject to violent wave slamming and vibrate consequently during storms. A series of model tests are carried o...The superstructures of marine structures supported by the elastic legs and located in the splash zone will subject to violent wave slamming and vibrate consequently during storms. A series of model tests are carried out to investigate the wave impacting on the open structures supported elastically. Three kinds of models with different natural frequencies are designed. The characteristics of the wave pressures on the three models are compared. The durations of the uplift forces and the corresponding accelerations of the structure during wave impact are analyzed simultaneously. The distributions of the peak impact pressures on the subfaces of the plates with different supporting stiffness are given. The relationship between the uplift force on the three models and the relative clearance are obtained. The spectral properties of the slamming loads on the three different structures are compared. The experimental results indicate that the behaviors of the impact pressures, the uplift forces and accelerations of the plates with small natural frequencies are obviously different from those of the plates with larger natural frequencies within the range of the experimental parameters.展开更多
基金This reseaschis supported by the National Natural Science Foundation of China (Grant No50409014) by the Science Foundation of Liaoning Province (Grant No20041075)
文摘The purpose of this paper is to investigate the instantaneous properties of wave slamming on the plate structure of an open structure.The advanced instantaneous measuring technique-Particle Image Velocimetry(PIV) is applied to acquire the instantaneous velocity field of wave slamming.From the cross-correlation analysis results of the images captured by the CCD camera,the flow fields of wave impacting on the structure are displayed visually,and the instantaneous whole-field fluid velocity vectors are obtained.The relation between the instantaneous peak impacting pressures and the instantaneous velocities of water particles is studied by probability analysis.
基金supported by the‘New Century Outstanding Talent’Scheme of the Ministry of Education of China(Grant No.NCET-07-0135)
文摘A numerical irregular wave flume with active absorption of re-reflected waves is simulated by use of volume of fluid(VOF)method.An active absorbing wave-maker based on linear wave theory is set on the left boundary of the wave flume.The progressive waves and the absorbing waves are generated simultaneously at the active wave generating-absorbing boundary.The absorbing waves are generated to eliminate the waves coming back to the generating boundary due to reflection from the outflow boundary and the structures.SIRW method proposed by Frigaard and Brorsen(1995)is used to separate the incident waves and reflected waves.The digital filters are designed based on the surface elevation signals of the two wave gauges.The corrected velocity of the wave-maker paddle is the output from the digital filter in real time.The numerical results of regular and irregular waves by the active absorbing-generating boundary are compared with the numerical results by the ordinary generating boundary to verify the performance of the active absorbing-generator boundary.The differences between the initial incident waves and the estimated incident waves are analyzed.
基金supported by the National Natural Science Foundation of China(Grant No.51179030)the Innovative Research Group National Natural Science Foundation of China(Grant No.51309056)
文摘The superstructures of marine structures supported by the elastic legs and located in the splash zone will subject to violent wave slamming and vibrate consequently during storms. A series of model tests are carried out to investigate the wave impacting on the open structures supported elastically. Three kinds of models with different natural frequencies are designed. The characteristics of the wave pressures on the three models are compared. The durations of the uplift forces and the corresponding accelerations of the structure during wave impact are analyzed simultaneously. The distributions of the peak impact pressures on the subfaces of the plates with different supporting stiffness are given. The relationship between the uplift force on the three models and the relative clearance are obtained. The spectral properties of the slamming loads on the three different structures are compared. The experimental results indicate that the behaviors of the impact pressures, the uplift forces and accelerations of the plates with small natural frequencies are obviously different from those of the plates with larger natural frequencies within the range of the experimental parameters.
