Overlapping

[Notwal]

Just a quick question about KSP's aerodynamic accuracy. If to wings were inside of each other, (and they were the same model) would the game see that as two wings and therefore twice the lift, or would it just count it as one wing?

[Geschosskopf]

I'm no expert on this, but here's the general impression I've gotten from not paying too much attention to what the knowledgeable folks say...

Stock pre-1.0, it didn't matter a bit where you put wings.  They could all be clipped inside the fuselage and still provide their full lift.  This was often done to avoid making obvious biplanes of what were supposed to be sleek jet fighters and such.

Stock post-1.0.  I THINK that areas of wing clipped inside fuselages no longer count for lift, drag, and whatnot, but that all the area of the wing protruding out from the fuselage still counts whether it overlaps another wing part or not.  Partially overlapping wing parts is frequently done for aesthetic and/or COL placement reasons and I've never noticed any change in the amount of lift produced by the overlapping parts.  So in your example of completely overlapping, identical wing parts, I'd think the game would still treat it as 2 separate and complete wing parts.

FAR, however, I THINK would not count the overlapping areas, but I'm not certain.

But in any case, overlap parts at your peril.  The Kraken finds overlapping parts very tasty.

[Claw]

5 hours ago, Notwal said:

would the game see that as two wings and therefore twice the lift

Twice the lift, so long as you're not stuffing them into a fairing or closed cargo bay. Stock KSP isn't much bothered by clipping into pretty much anything, but they do get shielded by the fairings and cargo bays.

[Red Iron Crown]

KSP ignores clipping for most aero calculations, so it should be twice the lift. The exception is if it clips into a cargo bay, service bay, or fairing enough to make it count as shielded, then it will generate no lift (or drag).

Edit: NinjaClaw!

[AmpsterMan]

Another thing to point out is that the drag will also be twice as much. So if you put something in front of the wing, or put the wing inside the fuselage, it would still generate drag. The only thing is that the drag would get applied in a different area, so it may behave a little differently than you might have thought.

[bewing]

You can also use the offset tool to make the two wings not be precisely overlapped, to avoid the issue.