非线性海洋内波的理论、模型与计算1) 王展*†2)(),朱玉可** THEORY, MODELLING AND COMPUTATION OF NONLINEAR OCEAN INTERNAL WAVES1) Wang Zhan*†2)(),Zhu Yuke** 图9. (纹影图)密度分层流体中由垂直方向周期振动的小圆柱产生的四个内波波束形成圣$\cdot$安德鲁十字现象, 不同频率的振动可产生不同的夹角: 左图振动周期为5 s, 右图为6 s (http://www.gfd-dennou.org/library/gfd_exp/exp_e/doc/iw/guide01.htm) Fig.9. Visualization of St. Andrew’s cross excited by a vertically oscillating circular cylinder in a density stratified fluid with constant buoyance frequency. The angle of arms is determined by the period (or frequency equivalently) of oscillation which is 5 s on the left and 6 s on the right (http://www.gfd-dennou.org/library/gfd_exp/exp_e/doc/iw/guide01.htm)