The results show that the interaction between a viscous vortex ring and a free surface is different from the inviscid one.

结果表明：由于粘性的存在，使得涡环与自由表面的相互作用与无粘情形相比有许多不同。

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Beginning with the prescribed wake model, a Semi Empirical Correction for the vortex core effect on rotor wake is made and free wake calculation is carried out.

首先从预定的广义尾流入手，并引入尖涡涡核作用的半经验修正，对旋翼的自由尾流进行计算分析。

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The free vortex aerodynamics window is used to be the window of high power laser beam, which takes advantage of the centripetal force of the free vortex motion of fluid.

自由旋涡气动窗口是利用流体微团作自由旋涡运动的离心力来平衡大气与光腔压力差，来作为高能激光束的输出窗口。

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