[8051]

For a given fan size (e.g. 120mm, 127mm, 140mm) can a thicker fan produce as much static pressure or CFM as a thinner vaneaxial fan at the same RPM? For example if we have two 140mm fans, one a vaneaxial of 38mm thickness and the other a 51mm thick non-vaneaxial fan can the 51mm thick fan match the static pressure or CFM of the vaneaxial by having longer blades w/a greater pitch at the same RPM? What about at the same dBA?

 

[8051]

I'm a bit lost as I thought the only difference was having vanes infront or behind, thus you could just add them to any axial.

You don't much see vaneaxial fans in the PC world. Vaneaxial fans have a rotor and a stator. The stator are vanes designed to change the rotational energy of a fan's output into static pressure.
Here's a picture of the stator side of a vaneaxial fan: