A hydroelastic model is developed for the problem of linear wave interaction with a submerged horizontal flexible porous structure in three-dimensions. The generalized expansion formulae with orthogonal mode-coupling relations are derived by expanding Fourier cosine series in a channel width. Using eigensolutions, various aspects of hydroelastic wave behaviour in a channel with a porous plate submerged in finite water depth is investigated. Further, the usefulness of the expansion is analysed through a real physical problem of wave diffraction by a submerged flexible porous plate connected with mooting lines in three-dimensions. The accurateness of the three-dimensional solution is inspected and the hydroelastic behaviour of the submerged porous structure is analysed for oscillation modes, mooring stiffness, and porous-effect parameters on numerical assessment of reflection, dissipation coefficients, and plate displacements in different cases. The analysis of current hydroelastic behaviour will be beneficial for future design of a device for wave energy absorption in three-dimensions.

针对水下三维柔性多孔结构与线性波相互作用问题，建立了水弹性模型。通过在通道宽度上扩展傅立叶余弦级数，导出具有正交模式耦合关系的广义扩展公式。使用本征解，研究了浸没在有限水深的多孔板的通道中水弹性波行为的各个方面。此外，通过将浸没的挠性多孔板与三维模拟线连接的浸没式柔性多孔板，通过波衍射的实际物理问题来分析膨胀的有用性。检查了三维解的准确性，并分析了振动模式，系泊刚度，和多孔效应参数对不同情况下反射，耗散系数和板位移的数值评估。当前水弹性行为的分析将有助于将来设计三维波浪能吸收装置。