ahhhhh

I know the answer to that!

there is two types of drag Parasite and induced.

induced drag is a direct component of lift... the more lift, the more induced drag. parasite drag is from non lift producing objects that interfer with the airflow, like sideview mirrors etc.

thats my aeronautical knowledge... I flyem, I dont design um.

 

[QUOTE=Fyrestrike,Nov 7 2007, 04:03 PM]What's that?

 

Maybe the wing was optimized for a certain angle of attack (AOA) at a certain speed? Is it possible to design a static (non-active) wing that is equally efficient at all AOA's given a speed AND at all speeds given an AOA?

About the mounts, if most of the air blowing by them is dirty, then fairings might not have as big of an effect, correct? I agree that a simple "tape 'em solid" method would be better than nothing

 

Not all, no. But within a range, yes.

As you change speeds, you change Reynolds Number. This affects how the wing works. It's basically an indicator of how important viscous effects are. The slower you go, the lower the RE.

Typically airfoils have a "bucket" in their drag polars. This is a range of AOAs where the lift is affected by the angle of attack more than the drag is. However, when you get out of that range of alphas then the drag becomes much more affected than the lift is. This drag is "form drag".

That's in 2D. Then you get some 3D effects due to the non-infinite aspect ratio. These reduce lift and add more drag. This drag is "induced drag".

While you are in the bucket you will see lift and induced drag varying with alpha, but form drag not so much. When you are outside of the bucket you see form drag varying quite a bit, but lift and induced drag not so much.

This bucket is basically defined by the region where the flow stays mostly attached to the airfoil. When it separates, that's when you are out of the bucket. It looks to me like this wing (at the higher angles, anyway) is probably separated out on the tips.

 

mike:

for aftermarket wings like this; how does one go about determining if the endplate depth is sufficient, or could be improved?

 

Make a bigger one and see if it helps or hurts. The endplate will increase lift and reduce induced drag, but it will have parasitic drag of its own. Thus, it's a tradeoff.

It's generally more effective to extend it on the suction side of the wing and to the back. (Down and back on a race wing, but up and back on an airplane, where they are known as winglets.)

 

I have the dumb.

 

damn, I forgot about that stuff

 

 

It would be a lot more useful to know how the wing interacted with the roof. I'm not so concerned about clean air as what angle the air is flowing over the wing.