Numerical study on the second-order hydrodynamic force and response of an elastic body – In bichromatic waves
Numerical study on the second-order hydrodynamic force and response of an elastic body – In bichromatic waves
复制标题
DOI：
10.1016/j.oceaneng.2020.107870
复制
发表时间：
2020-12
影响因子：
5
通讯作者：
Kyeonguk Heo;M. Kashiwagi
中科院分区：
文献类型：
--
作者：
Kyeonguk Heo;M. Kashiwagi
采用高阶边界元法研究了双色波中弹性体的二阶水动力和响应。在边界积分方程中采用自由表面波绿色函数，并采用二次型函数进行离散，以解决边值问题。在边界条件中，重新定义了物体表面的法向量变化，以考虑刚体和弹性体运动。特别适用于二阶物体边界条件和零航速情况下几种广义力的推导。在二阶量中，采用广义模态下的间接公式，得到了二阶速度势力，并分析了各分量的贡献。二阶力的验证首先通过与已公布的数据进行比较。计算了半球刚体运动所受的激振力，并与其它半解析和数值计算结果进行了比较，两者吻合较好。利用简化的结构模型，对弹性半球的几种竖向弯曲模态进行了数值试验。得到了两节点垂向弯曲的二阶水动力和响应，并验证了二阶量的性质。
The second-order hydrodynamic force and response of an elastic body in bichromatic waves are studied by using higher-order boundary element method (HOBEM). To solve the boundary value problem, the free-surface wave Green function is adopted in the boundary integral equation and the discretization is conducted by quadratic shape function. In the boundary condition, the normal vector variation on the body surface is re-defined to consider both rigid and elastic body motions. It is invoked especially for the derivation of second-order body boundary condition and several generalized forces in zero forward speed condition. In the second-order quantities, the second-order velocity potential force is obtained by using indirect formulation in the generalized mode and the contribution of each component is investigated. The validation for the second-order forces is first conducted by comparing with published data. The excitation force on the rigid body motion of a hemisphere is calculated and showed a good agreement with other semi-analytic and numerical results. Using simplified structural model, several vertical bending modes of an elastic hemisphere are considered as a numerical test. Second-order hydrodynamic force and response for the two-node vertical bending are obtained and properties of second-order quantities are confirmed.