Aerodynamics of Big-S wings vs basic wings

[MitchS]

Hi all!

The standard wings, visually at least, have the same width at the root as they do at the tip, and at the front as they do at the back. They're boards with nice edges. The Big-S series of wings, however, has varying thicknesses and a much more dynamic profile. They taper to the wingtip, and have a thicker airfoil, several times thicker than the standard wings. I know this thickness is probably meant to model the fuel capacity and look nice with larger planes, but I'm curious if there are any other aerodynamic effects of the dimensions that distinguish them from their early-tech-tree cousins.

Do Big-S wings have higher drag (like they would, intuitively, judging by their size)? Do they produce more lift at low speeds than a standard wing constructed to the same planform shape? Do they produce more lift at the wing root than at the wing tip? Heck, does it stall at the wing root first? ...or is it just a different-looking standard wing that you can fill with fuel?

Those of you with more programming experience than me (i.e., x>0) would probably be able to navigate the part file or aero model to see any differences, so besides designing and flying a carefully controlled flight test experiment, I can't answer these questions as well as you guys can.

Thanks!

[AeroGav]

No,  all aerodynamic surfaces have the same lift to drag ratio at the same mach number and angle of attack.   Every wing piece is identical, the only difference is in lift rating (wing area) .  A wing or control surface with a lift rating of 1 will produce twice as much lift and twice as much drag as one with a rating of 0.5

In addition, all wings have the same mass to lift rating ratio, except for the basic swept wing, which is twice as bad.

Pure 100% control surfaces, , have half as much lift rating as a wing would of the same mass .  

This is easy enough to prove if you go into the ALT f12 menu, physics, aero, and tick the "display aero data in action menus" box.

Build a plane with several different types of wing on it, pin the right click menus in place, then take screenshots in various flight conditions.  If you analyse these afterward, you will see that the lift:drag ratio is same for all.

Also, you will notice that fuselage pieces and engine nozzles create way more drag than wings.

 

[Aegolius13]

One thing to add: the game does take wing shape into account in determining where the lift created by a wing is located.  For example, if you put a Big S wing on a plane and then reverse it, you will notice the Center of Lift shifts toward the wider part of the wing (i.e., the back, if you use it in a normal delta shape).  But beyond the location of the lift force,  wing shape does not matter.

The end result of all of this is that the Big S wing (along with its little brother, the wing strake) is basically way, way better than any other wing.  It gives you fuel storage without the cost and drag of an outside tank, and at the same lift/weight ratio of the other standard wings.  Note that the the FAT-455 wing also offers fuel storage, but it has a very low heat tolerance that makes it tricky to use in spaceplanes.  And the Big S wing's large size is helpful, vs. making potentially weak/floppy arrays of wing connectors (though autostrut has helped with this issue).

Thus, you see Big S wings on practically all efficiency-optimized planes.  I wish the game would offer some more comparable wings for better variety, but that's the current state of things.  

 

[GoSlash27]

^ What AeroGav said.

 A wing is a wing is a wing. The only practical differences are lift to mass and thermal rating, but wings account for a tiny percentage of the total mass. Moreover, BigS wings carry your fuel with much less drag penalty than tanks.

If you have access to BigS shuttle wings, I recommend using them.

Best,
-Slashy

[Sharpy]

18 hours ago, AeroGav said:

No,  all aerodynamic surfaces have the same lift to drag ratio at the same mach number and angle of attack.   Every wing piece is identical, the only difference is in lift rating (wing area) .  A wing or control surface with a lift rating of 1 will produce twice as much lift and twice as much drag as one with a rating of 0.5

Whoooa.

Lift rating zero.

The stock aerodynamics model is affected by the lift rating, but it takes plain geometry into account too.