Do wings apply real lift with the new aero?

[CaptainTurbomuffin]

Before 1.0, wings had no lift at all, they acted like large flat surfaces, like paper-airplane wings. However, we all know how real aircrafts have lift from their wings. Do we have that with the new aerodynamic system? Or in FAR? Or if my wings are still large flat surfaces, if I use them to make a 3D wing like the Stearwing A300 has, will that have aerodynamic lift?

Edited August 8, 2015 by CaptainTurbomuffin

[cantab]

Wings act like wings in stock and FAR aerodynamics. Both can handle putting pieces next to each other to make bigger wings, but if you try and make your own airfoil shape from the wing pieces that isn't going to work. Basically despite the appearances you can regard the wings as already being airfoils.

[tutike2000]

Lift in real life can only be generated by 'pushing down on' or 'turning' the flow of air. Both the upper and lower sides of a real wing contribute to this.

In (stock) KSP however, a single part/wing section will generate lift regardless of what other wing pieces are placed next to it, inside it, stuck to either side, glued on top, etc etc.

Not sure about FAR.

[LostOblivion]

Lift in real life can only be generated by 'pushing down on' or 'turning' the flow of air. Both the upper and lower sides of a real wing contribute to this.

Perhaps that is what you are indeed saying, but lift IRL is mostly generated from a lower pressure on the upper side of the wing where the air travels faster, which causes the higher pressure on the lower side of the wing to not compensate any longer, causing lift.

[GoSlash27]

Wings provided actual "lift" in old aero and they still do. If they had acted like large flat panels, lift and drag would've been proportional to the sine of pitch and on the same order of magnitude.

They actually provide lift proportional to the sine of twice the pitch and it's much higher than the drag they generate in the process.

Best,

-Slashy

[match]

In KSP lift is only developed when an angle of attack exists.

[Sharpy]

In real life the wings don't need to be angled to create lift.

Air moving over the back side of the wing creates under-pressure and pulls the wing upwards. A plane moving horizontally, with the bottom area of the wing parallel to the ground - essentially 0 AoA - will still lift in the air.

In KSP you can install a wing upside-down and it will behave the same way as installed normally - so yes, it works like "paper airplane"/"flat surface". The lift comes from the angle of attack, air compressed by lower surface and "thinned" by upper, so only wings at an angle to the ground will generate a force. A plane with horizontal wings and no control surfaces won't lift off unless tilted backwards.

Probably an important factor is that this way you can use wings as fins, launch airplanes vertically on rockets and use radial symmetry when attaching them (resulting in one of them being "upside down"). If the wings were profiled, working like IRL, the airplanes would be slighly easier to build and pilot, but a slew of other applications of wings would become unavailable.

[Weywot8]

Perhaps that is what you are indeed saying, but lift IRL is mostly generated from a lower pressure on the upper side of the wing where the air travels faster, which causes the higher pressure on the lower side of the wing to not compensate any longer, causing lift.

That's what they teach in school, but IRL aeronautical engineers get the real shebang. The relative contributions of lift from air-pressure differential and airflow redirect depends on circumstance but airflow redirect plays a larger role in many, many more scenarios like at cruising height for most commercial airlines where air pressure is a fifth of sea level.

This is a nice link http://www.aviation-history.com/theory/lift.htm

[cantab]

Oh joy, arguments over how planes fly.

Saying that a plane can fly with "Zero Angle of Attack" is one part misleading and one part vacuous, because it depends entirely on how you define 0 degrees angle of attack. The bottom surface of the wing is not very helpful though I feel. More common is the chord line - the line joining the leading and trailing edges. In the above diagram you can see that the chord line is not horizontal. Sometimes 0 degrees angle of attack is instead defined as the angle the wing generates zero lift at! For a symmetric airfoil those two definitions are the same (as should be obvious), for an asymmetric one they may not be.

Additionally the airflow aft of the wing depicted in the above diagram is incorrect. Aft of a real wing far from the ground the airflow is deflected downwards. It's an effect not always seen in wind tunnels due to differences between that environment and real flight but it's crucial to the real physics.

In any case a wide range of airfoil shapes are used, from the "classic" shape seen above, to symmetric airfoils, to designs that are concave on the lower surface.

I believe FAR assumes a shape like the "supersonic interceptor", but you could check with Ferram. Such a shape stands out as it's symmetric both top-bottom and front-back, freeing the player of concerns about orientation especially with wing parts that look like they have exactly that symmetry. Similar symmetry considerations would apply in newstock and even if the actual wing performance differs you will still get zero lift at zero angle of attack with respect to the chord line.

[QuesoExplosivo]

@Sharpy:

The air doesn't move faster because it has a longer path. Nothing requires equal transit time in that situation.

[Sharpy]

@Sharpy:

The air doesn't move faster because it has a longer path. Nothing requires equal transit time in that situation.

Pressure difference does.

Air is compressed in front of the wing and decompressed in the back, so it will naturally "pull" from the high pressure area towards the low pressure area. But of course the speed alone doesn't create lift, it's the pressure difference that does - the point that the air will accelerate towards the back being a side effect with little practical repercussions.

[CaptainTurbomuffin]

In real life the wings don't need to be angled to create lift.

so yes, it works like "paper airplane"/"flat surface". The lift comes from the angle of attack

Thank you, that's what I was looking for. You don't have to explain real-life aerodynamics, I am an expert of that, I just wanted to know how things work in my game. Thank you for replying onto the question.

[Edax]

I attempted to create a biplane last night and learned that the wings did not produce any lift at level flight or when going down the runway. Only the control surfaces would produce lift when activated. Oddly enough, when the biplane ever went below level flight, all the wings produced downforce. I have no idea why the wings are acting this way.

[Red Iron Crown]

They're symmetric airfoils, essentially. At negative angles of attack they produce downforce, at positive angles of attack they produce lift. I've found that having a small positive angle of incidence for the main wing on aircraft helps them perform much better.

[Vanamonde]

How real-world wings work is off-topic for this part of the forum. Please restrict the discussion here to the characteristics of KSP wings.