Characteristics of dynamic pressure on floating V-shaped breakwater
Ding Ning1,2, Yu Jianxing1, Hou Jiajia1,3
1.State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China; 2.Institute of Military Transportation, Tianjin 300161, China; 3.Tianjin Xingang Shipbuilding Heavy Industry Co. Ltd., Tianjin 300456, China
In order to determine the wave force(or moment)in design and structure analysis of floa-ting V-shaped breakwater, the dynamic pressure distribution and its amplitude on the wet surface of breakwater was calculated and analyzed in a regular wave. Considering the diffraction effect, the velo-city potential around the breakwater was calculated based on the 3D linear potential flow theory in frequency domain by using boundary element method and 3D Green functions, which were solved by both integral method and eigenfunction expansion approach. The dynamic pressure was calculated by using the linear Bernoulli equation according to the velocity potential just obtained numerically. Moreover, the dynamic pressure and its amplitude on the wet surface were estimated in a regular wave. The results of an example indicate that the dynamic pressure distribution on the wet surface is sinusoidal longitudinally and attenuating downward vertically. The distance between the two nearest peaks of dyna-mic pressure is approximately equal to the quotient of incident wave length divided by the cosine of the angle between the incident wave direction and the breakwater. Besides, the maximums of dynamic pressure(about 2 kPa)are on the free surface, while the minimums(about 0.2 kPa)are in the bo-ttom of breakwater, thus the dynamic pressure near free surface plays a very important part in wave force(or moment)of floating V-shaped breakwater.
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