Nobody every intended the 1701 to be "aerodynamic." THIS WAS NEVER THE INTENT. It was designed to be a spaceship, and part of the concept behind her was to avoid all the "traditional trappings of sci-fi," which included (but was not limited to) fins and wings and pseudo-aeronautical elements, of the sort that you'd see on "Rocky Jones, Space Ranger" ships.
I grant that it's possible that at some point, very early on, M.J. probably thought about putting the C57D saucer (or some "descendent" of that saucer) into the Enterprise design. And that certainly seems to carry through in the "triangles" which we're still, hypothetically, talking about..
It's also quite clear from M.J's drawings that he never envisioned the undercut. His own cross-section has no undercut, but rather had two full deck heights through the entire saucer disk element.
I suspect that the decision to implement the "undercut" was because of the shadow effect that it gave which helps differentiate between the edge and underside of the disk... something which, otherwise, is quite a bit harder to make out under many lighting conditions.
That, I'm convinced, is why it was REALLY done.
Now, as for why it was done as an "in-universe" explanation... aerodynamics simply doesn't hold up." There are all other possible explanations we can make up. All sorts of "magical" technology which doesn't really exist which we can associate with this. Hey, maybe it helps with the sensor system? Maybe it's associated with generating the deflector shields? Maybe it "improves warp dynamics?"
Those are all make-believe, so any of them "could be true." But as far as aerodynamics goes... that's one explanation we simply have to take off the table. Because that's a REAL science, and it's one that is well-understood. I studied the science myself, have devoted many hours in massive wind tunnel facilities, and have equipment which I have been responsible for the design of flying on several high-range military aircraft (including the F22 Raptor, T-38 2004 refit, and E-2C "Hawkeye 2000" and E-2D) and have spent a significant part of my decades working as an engineer in this very field, though, granted, at the moment my job is in a different arena, as the senior Mechanical Engineer for Valence Technologies, not directly in the aerospace arena.
Lots of us have dealt with this science. It's not ... forgive the pun... exactly "rocket science."
I've fun many calculations, using the same concepts I've discussed here, tested them experimentally, and found that the reality and the experimental data match. So, I'm sure, have several other folks here. And lots of other folks who've never posted on this BBS have performed similar experimentation.
Face it... the 1701 isn't aerodynamic, either by intent or by "happenstance."
Could it "fly" in an atmosphere? Sure... under constant power, and constant correction. If the F-111 can fly (and realize that this aircraft design is TOTALLY unstable!), the 1701 can do so if it's "under control." It doesn't need to generate aerodynamic lift, it can just pitch up a bit and rely on a percentage of the impulse thrust to keep it in the air. Or it can rely on antigravity. Or it can rely on someone in the lower decks sacrificing a freaking chicken!
Nobody's saying that a powered starship can't manuever in an atmosphere. But I'd hate to have to GLIDE one in, unpowered.
