两层流体中大直径圆柱体的水动作用力

研究了两层流体中大直径垂直圆柱体上的水动力特性．基于分离变量法，建立了绕射势和辐射势的解析解，导出了作用在大直径圆柱体上水动作用力的计算公式．与单层流体不同，对两层流体，作用在大直径圆柱体上的水动作用力，除了表面波模态的波浪力、附加质量和阻尼系数外，还有内波模态的波浪力、附加质量和阻尼系数．对所建立的求解模型进行数值计算分析的结果表明，在某个频率范围内，流体的分层效应对这些水动力量的影响是不可忽视的．

The Hydrodynamic Forces on a Large Diameter Cylinder in Two-Layer Fluid

The hydrodynamic characteristics of a large diameter cylinder in a two-layer fluid was considered. The analytic solutions for the corresponding diffraction and radiation problems were obtained by an eigenfunction expansion method, and the computational formulations for the hydrodynamic forces on the large diameter cylinder were given. The hydrodynamic forces on the large diameter cylinder in a two-layer fluid include not only the wave force, added mass and damping coefficient by produced the surface wave but the ones produced by the internal wave. This is different from the case of the uniform fluid. Some (examples) were given, showing that the density stratification has a relative large effect on the hydro-(dynamic) forces on the large diameter cylinder over a wide range of frequencies.