I’m trying to find out what purpose this type of design serves and how they are designed but have hit a wall with knowing what to even look for.
This piece of the voron stealthburner is the only example I can think of off the top of my head but I have seen them before in some sort of fan duct or funnel thing.
Which part of it do you mean, exactly? The narrowing? That funnels air so it moves faster.
The cone shaped part.