A boundary element method (BEM) model is presented for wave forces on structures composed of solid and porous surfaces, where the porous surface can be subject to either a linear or quadratic pressure–velocity relation. In the case of the quadratic relation, the solutions to the radiation and diffraction problems cannot be superimposed to obtain a solution for body motions in waves. Instead, a solution method is proposed which solves for the motion response and wave forces on the body simultaneously. Solutions for the radiation and diffraction problems are then obtained as special cases. Hydrodynamic identities and expressions for the mean drift force for combined solid-porous bodies are also derived. It is shown that in the case of a quadratic pressure drop, the hydrodynamic coefficients are no longer symmetric and the Haskind relation must be modified to account for the pressure drop across the porous surface. The BEM solution is verified against an analytical calculations and results for the excitation and mean drift forces are shown to agree well. A case study is presented for a floating truncated cylinder, with a concentric porous outer cylinder. It is shown that the porous outer cylinder significantly increases the damping at low frequencies, where wave radiation damping is low, leading to a lower motion response.

提出了一种边界元方法（BEM）模型，用于对由固体表面和多孔表面组成的结构上的波浪力进行处理，其中多孔表面可以经受线性或二次压力-速度关系。在二次关系的情况下，无法叠加辐射和衍射问题的解决方案以获得波中人体运动的解决方案。取而代之的是，提出了一种解决方法，该方法同时解决身体上的运动响应和波动力。然后作为特殊情况获得辐射和衍射问题的解决方案。还推导了组合固孔体的流体动力学特性和平均漂移力的表达式。结果表明，在二次压降的情况下，流体力学系数不再对称，必须修改Haskind关系以解决多孔表面的压降问题。通过分析计算验证了BEM解决方案，并且励磁和平均漂移力的结果显示出很好的一致性。提出了一个带有同心多孔外圆柱的浮动截断圆柱的案例研究。结果表明，多孔外圆柱体在低频下显着增加了阻尼，在这种情况下，波辐射阻尼很低，从而导致较低的运动响应。具有同心的多孔外圆柱。结果表明，多孔外圆柱体在低频下显着增加了阻尼，在这种情况下，波辐射阻尼很低，从而导致较低的运动响应。具有同心的多孔外部圆柱体。结果表明，多孔外圆柱体在低频下显着增加了阻尼，在这种情况下，波辐射阻尼很低，从而导致较低的运动响应。