40mm Air Penetrator (MAX static pressure)

WORK IN PROGRESS. Still doing testing on all STL's.

I got inspiration for this fan "cover" from my actual Silverstone Air Penetrator. They have an excellent video demo (linked below) showing how direct the airflow is compared to a non-ducted axial fan. The AP121 has GREAT static pressure, so by mimicking this design for my 40mm part cooling fan, I hoped that the little axial fan I use on my cooling setup can provide enough CFM and SP to push air out effectively. This part is intended to be mounted on the REAR of the fan, which is why I used a cone, so it cannot be mounted backwards. If there is enough interest, I could make a non conical version and indicate which side faces the fan.

https://youtu.be/8m8fC809TK0

The cover DEFINITELY works, the air comes directly out of the fan, rather than out of the edges, eliminating the dead spot behind the motor. The reason for the different fin amounts is noise. Just a note, the AP121 has 35 fins, but that was far too many for the tiny 40mm fan, which is why the max is 29.

Here are my (non-scientific) findings:
29 fin, best tunnel effect, worst airflow.
25 fin, great tunnel effect, good airflow.
21 fin, good tunnel effect, great airflow.
17 fin, worst tunnel effect, best airflow.

I personally run the 25 fin version for my part cooling fan.