free surface vortex

例句：

1. 1. The wind causes the free surfacevortex to swirl around the boat.
   风吹动自由表面涡流，在船周围旋转。
2. 2. The free surface vortex is responsible for the formation of waveson the ocean surface.
   自由表面涡流是海洋表面波浪形成的原因。
3. 3. The freesurface vortex can be observed inthe wake of a ship as it movesthrough the water.
   当船只在水中移动时，可以观察到自由表面涡流。