波浪和水流对大直径圆柱的共同作用力

Wave-Current Forces on A Large Vertical Cylinder

本文将波流共同对圆柱作用的速度势分成合模势(无自由表面的绕流速度势)、流兴波势和非定常波势三部分。忽略小量的流兴波势,考虑合模势对非定常波势的影响,用直接边界元法求出非定常波势,从而求出波流共同对圆柱的作用力。提出了沿流线的自由表面条件和波流共同作用下散射波的幅射条件。文中给出了波流对大直径圆柱作用力曲线,可供工程设计使用,适用条件是相对水深d/L>0.15,相对流速U/c<0.2。

In this paper, the velocity potential exited by wave-current on a cylinder is divided into three parts-the double model velocity potential, the steady current exiting wave potential and the unsteady diffraction wave potential. Because the steady current exiting wave is much smaller it can be neglected. The unsteady wave potential is computed by using Direct Boundary Element Method while the effect of the double model velocity potential is considered. So the wave-curent forces on large vertical cylinder are computed. The free surface condition along streamline and the radiation condition are investigated. The results are given and can be used for engineering.