Winglet?

[Orange Anchor]

A related question, is what to term to classify these things under. Let me illustrate via a negative.

They are not leading edge devices
They are not spoilers
They are not airfoils.......


ideas?

b.

You will see lots of 'fixes' as Tgrayson correctly notes if you look. Stall strips, vortex generators,

and the aero treatments are not limited to the wing.

or a 'dogtooth' for example.

Note the ventral fin added to the Crusader.

LOTS of aero-fixes in the tool kit.

 

[beasly]

You will see lots of 'fixes' as Tgrayson correctly notes if you look. Stall strips, vortex generators,

and the aero treatments are not limited to the wing.

or a 'dogtooth' for example.

Note the ventral fin added to the Crusader.

LOTS of aero-fixes in the tool kit.

This is fun, thank you. I never heard of a Ventril Fin, before.

cordially,
b.

 

[beasly]

I've always heard of these "wing fences" referred to as "stall fences." The Beech 1900 has them as do many other aircraft.

Thanks, got it in the lesson plan draft.

Cordially,

b.

 

[Orange Anchor]

Are modern aircraft now moving away from winglets for raked wingtips? Aren't those more efficient?

The 'raked wingtip' is just another device to try and diminish the effects of the vortex. Remember the 777 was initially going to be offered with folding wingtips but none of the airlines opted for it. Next Boeing offered the 'raked wingtip' on the 777.

FWIW, before Orville and Wilbur flew, an inventor had already come up with the idea of 'wing plates' at the end of the wing to stop the spanwise flow and to control the vortex. Wing plates are still in use.

 

[beasly]

The 'raked wingtip' is just another device to try and diminish the effects of the vortex. Remember the 777 was initially going to be offered with folding wingtips but none of the airlines opted for it. Next Boeing offered the 'raked wingtip' on the 777.

FWIW, before Orville and Wilbur flew, an inventor had already come up with the idea of 'wing plates' at the end of the wing to stop the spanwise flow and to control the vortex. Wing plates are still in use.

Cool stuff. Some thoughts.

Regarding pic 1

Who at Boeing decided against the "folding wingtip?" Engineer or suit?

Regarding pic 2.

To my rookie eye, there are two things going on here.
1. reduction of drag via the wingtip
2. redirecting the wind into the intake of the engine--increasing performance of the engine.

b.

 

[Orange Anchor]

Cool stuff. Some thoughts.

Regarding pic 1

Who at Boeing decided against the "folding wingtip?" Engineer or suit?

Guy at the airline with the $$. Complexity, additional weight, etc. Also, with a longer wingspan, parking the airplane would be a problem for some carriers. The airplane has to fit within a given 'box' when parking.

Note that Aviation Partners is now working WITH Boeing and adding winglets to the 737, 757 and 767. It is reported they are working on a possible winglet for the 777.

As you can imagine, it is not merely a matter of bolting on a winglet. The whole wing has to be considered because with the winglet, the forces are being re-distributed. When looking into this, I stumbled across the fact that all wings are actually created as 3 wings.. the one that comes out of the jig, the one attached to the airplane and on the ground and the wing in the air. For some reason I had never considered that point.. all the bending, twisting and turning.

Regarding pic 2.

To my rookie eye, there are two things going on here.
1. reduction of drag via the wingtip
2. redirecting the wind into the intake of the engine--increasing performance of the engine.

b.

The wing in the back keeps the car on the track. The winglet on the front does the same. By creating a downward force, it nails the car to the track.

Hadn't thought of it but you may be right about directing the airflow into the intakes. Probably not as critical as working on airflow into a jet engine but you may have a point.

 

[Polar742]

Regarding pic 2.

To my rookie eye, there are two things going on here.
1. reduction of drag via the wingtip
2. redirecting the wind into the intake of the engine--increasing performance of the engine.

b.

The plates on the wings to keep air over the wings. (Main plane is the front wing term). The Main plane is also used to direct air over the tires, as they create drag and turbulence. You'll see treatments on many open wheel cars to do this too.

If you look directly behind the front suspension, you'll see vertical plates. And if you look real close, you'll see them attached to a horizontal plate that runs beneath the car. That's the Barge Board. The purpose of that is to direct air under the car. The car's undertray is an aerodynamic device with a diffuser at the back that controls the air. The undertray provides about 50% of the downforce (lift) for the car.

I'm not sure what formula that car is, but usually, the engine intake is where the rollhoop sits behind the driver's head. It's usually formed in a similar fashion to the scoop on a P-51, where it uses a design to try to increase the air pressure into the intake manifold.

The sidepod intakes are usually for the radiator. So, I'm not sure if that's what you were referring to for the "engine intake".

Learn about F1 aerodynamics, it's absolutely amazing. There are some very good sites for technical explination. And learn about the cooling system on the P51 and how it actually generated thrust.

Good stuff.

 

[falconvalley]

Are modern aircraft now moving away from winglets for raked wingtips? Aren't those more efficient?

Depends on what the operators want. A raked wingtip is a more efficient alternative than a winglet. Wings can only be extended so much before they get so long that they are a pain around terminals, so sometimes they just have to go with actual winglets instead of the raked wingtip.