透水cosine-type同心圆柱波浪绕射研究

在势能流及微小振幅波理论假设下,采用复合边界元素法(CBEM)数值解析规则波通过单根外壁透水cosine-type型同心圆柱结构物绕射。将cosine-type外壁不透水条件改为透水外,并在内部设有一半径为b的不透水内圆柱共同组成同心圆柱,为了验证CBEM数值模式正确性与可行性,将其退化成圆柱,均得到合理结果。数值计算条件包含波浪正向入射凸端、透水参数及绕射参数,探讨波浪通过单根cosine-type同心圆柱体四周水面波动变化情况,并与双重圆筒同心圆柱作比较。计算结果显示结构物外壁采用透水型式,可以大幅降低cosine-type同心圆柱体四周整个波浪绕射场的水面波动。

Wave diffraction by a porous cosine-type cylinder with a solid interior cylinder

In this paper, wave diffraction by a porous cosine-type structure with a solid interior cylinder system is investigated. Under the assumptions of potential flow and linear wave theory, a numerical solution has been obtained by a composite boundary element method (CBEM). The exterior cylinder is porous, and its diameter exhibits a cosine-type variation and is considered to be thin in thickness and the interior cylinder is impermeable. Both surface-piercing cylinders are rigidly fixed at the sea bed. The accuracy and validity of the method have been compared to the limit case of circular cylinder. Excellent agreement has been observed. Numerical results have presented the magnitude of the diffraction coefficient with porous wall-effect parameter, and diffraction parameter. It has been found that the porous effect parameter of the structures may result in a significant reduction in the diffracted wave field.