3. Siren 汽笛

If you direct an air flow onto a rotating disk with holes, a sound may be heard. Explain this phenomenon and investigate how the sound characteristics depend on the relevant parameters.

如果你将气流引导到一个带孔的旋转盘上，可能会听到声音。请解释这一现象并研究声音特性如何依赖相关参数的。

Stream lines over a hollow rotating disk