Whenever a fluid has a nonzero vorticity, it looses some of its energy in a form of sound wave. Formally is this mechanism described by Lighthill's equation or some related model (like e.g. Curle's theory). But I have a lack of physical intuition on this process. Derivation of the Lighthill's model is based on disturbances of momentum flux tensor in a stokesian fluid, so nothing straightforward. I am fully capable of understanding this derivation with all the maths, but I can't "explain that to my grandmother in plain english".
Could anybody provide that sort of explanation?
Note 1: I am mainly interested in generating noise in turbulent fluid states. Tone-like sounds generated by periodical emerging of a macroscopic vortex eddies (Strouhal's Aeolian sound) are clear to me.
Note 2: I am aware of brilliant M. C. Howe's publication on the Theory of Vortex Sound. I have read it. But it is mainly on applied maths - that's why I am asking this question.