Nonlinear interactions between deep-water waves and currents
Nonlinear interactions between deep-water waves and currents
复制标题
深水波与海流之间的非线性相互作用
DOI：
10.1017/jfm.2011.436
复制
发表时间：
2011
影响因子：
3.7
通讯作者：
D. Peregrine
中科院分区：
文献类型：
--
作者：
R. Moreira;D. Peregrine
摘要采用边界积分方法，数值研究了非线性对深水中线性水波与底层流相互作用的影响。假设电流是二维的和静止的，由位于自由表面下方的奇点分布引起，其施加尖锐和温和的表面速度梯度。对于“缓慢”变化的电流，完全非线性的结果证实，相反的电流引起波陡化和打破的区域内发生的高收敛的射线。对于“快速”变化的水流，波浪阻塞和破碎更为突出。在这种情况下，当施加足够强的逆流时观察到反射，证实了在焦散内积累的至少部分波能可以以部分反射和波浪破碎的形式释放。对于双色波，完全非线性的结果表明，部分波阻塞发生在波组中的各个波分量，波成为几乎单色的阻塞区上游。
Abstract The effects of nonlinearity on a train of linear water waves in deep water interacting with underlying currents are investigated numerically via a boundary-integral method. The current is assumed to be two-dimensional and stationary, being induced by a distribution of singularities located beneath the free surface, which impose sharp and gentle surface velocity gradients. For ‘slowly’ varying currents, the fully nonlinear results confirm that opposing currents induce wave steepening and breaking within the region where a high convergence of rays occurs. For ‘rapidly’ varying currents, wave blocking and breaking are more prominent. In this case reflection was observed when sufficiently strong adverse currents are imposed, confirming that at least part of the wave energy that builds up within the caustic can be released in the form of partial reflection and wave breaking. For bichromatic waves, the fully nonlinear results show that partial wave blocking occurs at the individual wave components in the wave groups and that waves become almost monochromatic upstream of the blocking region.