RE: Fluid Dynamics question
Yes, they are used as inlets, but we have also used them as outlets and have not had any problems with them so far. I don't have any tests to back this up. However, we did not use an exact NACA duct. We modified ours and made it a bit more rounded, but the same idea is still there. I would love to know if anyone has any tests on this. I could set up an experiment, but if someone else has data, it would save me a lot of time.
Now, keep in mind that I could be wrong, so I don't want to hear anyone bash me.