This is a funny whistle which combines the principle of a turbine with a air raid siren.

this model has almost no sense but to be fun :)

it gets better over time due to the grinding of the seams on the barrel
a bit of silicone spray in the gap of the barrel helps aswell

unfortunately, the air consumption is pretty high - you'll need good lungs

Attention:
Your printer MUST be able to maintain a clear gap of 0.2mm - otherwise the barrel won't rotate

HINT:
This Model is really just for fun because i like it and it's a cool principle.
BUT if i print 3 Whistles, one works well, one does not - all work "sort of"... but it's not consistent.
If your first print is not that good or comsumes much air - just give it another try. 

If you cant solve these problems, try the versions with a larger gap.
you can download a version with 0,25mm and 0,30mm clearance between the barrel and the housing.
but those will consume even more air.


AMAZING:
UFD Tech found this design and featured it on their channel:

Version: T4 (Turbine 4)