My E3d blower system with small radial fans; both generic 4020 units, and TFB45A 45mm fans from SEPA.
The generic 4020 units are ubiquitous; but have not lasted very well in my use. The SEPA units are bigger, but have proper bearings and higher airflow, so I upgraded.
This design achieves quite a decent airflow around the nozzle. The fans are angled slightly and have clearance at the top for a Precion Piezo module.
I have re-mixed the 'official' e3d duct body and extended that with angled and spaced mounting brackets to either side. The fan ducts are printed separately and clip snugly onto the duct.
Doing this as two separate models makes for a very printable design, print two of the fan plates and one main body without support and as oriented in the files; the body may need a brim for adhesion! Fit the various fans with 3mm screws (self tap), and clip together.
There are some pins on the body for a smallish o-ring to make it more secure if it starts rotating around the heat sink (mine did, but only when printing PCABS at 290c.. so ymmv).