Mac790
Well-Known Member
I'm collecting informations about aft swept wings. Somebody might wonder why I'm thinking about swept wings? Generally there are at least two reasons for it, first transonic speeds, second let's call it "problems" with C.G, in my case it's latter.
I could solve it "easily" with just one of the following approach:
- change design to more "conseravtive" one, and remove sweep completely
- try to move all unnecessary equipment in my case to the front of the fuse, to solve C.G problems
- move wing back, and decrease sweep
- incorporate bigger wash-out, that would be probably the best idea, but, the airfoil that I'm considering has much higher cd at lower (negative) AOA, for example cd at cl 0.1 is 2 times bigger that at cl 0.3.
I believe the key is to use each of above approaches (without first of course) partly, I mean move all possible components forward, move wing a little bit back, decrease sweep a little bit, add moderate wash-out. I was thinking also about possible mixing aerodynamic and geometric twist, but honestly I haven't heard about approach like that, are there any red lights for it?
I could also use more radical approach and add some unnecessary weight (lead) to the front of the fuse .
Other ideas, boundary layer fence, dog-tooth, I'll need to check out also winglets influence.
Do you guys have other approaches for that, any good papers, there is at least one NACA Langley report about it, back from 30's that deals with tapered and swept wings, but the problem is that they were using thinner airfoil sections at the tip, with approach like that, even rectangular wing stall at the tip, so I wouldn't call it a very useful report, but I'll take a look at it again, maybe I missed something ( I read it long time ago).
To make things harder, the wing I'm thinking about has high AR around 13 at the moment, I want limit this thread only to problems with lift distribution, and wing tip stalls problem, I want exclude problems with pitching moment at the stall for swept high AR wings, and eventually stability issues.
Seb
I could solve it "easily" with just one of the following approach:
- change design to more "conseravtive" one, and remove sweep completely
- try to move all unnecessary equipment in my case to the front of the fuse, to solve C.G problems
- move wing back, and decrease sweep
- incorporate bigger wash-out, that would be probably the best idea, but, the airfoil that I'm considering has much higher cd at lower (negative) AOA, for example cd at cl 0.1 is 2 times bigger that at cl 0.3.
I believe the key is to use each of above approaches (without first of course) partly, I mean move all possible components forward, move wing a little bit back, decrease sweep a little bit, add moderate wash-out. I was thinking also about possible mixing aerodynamic and geometric twist, but honestly I haven't heard about approach like that, are there any red lights for it?
I could also use more radical approach and add some unnecessary weight (lead) to the front of the fuse .
Other ideas, boundary layer fence, dog-tooth, I'll need to check out also winglets influence.
Do you guys have other approaches for that, any good papers, there is at least one NACA Langley report about it, back from 30's that deals with tapered and swept wings, but the problem is that they were using thinner airfoil sections at the tip, with approach like that, even rectangular wing stall at the tip, so I wouldn't call it a very useful report, but I'll take a look at it again, maybe I missed something ( I read it long time ago).
To make things harder, the wing I'm thinking about has high AR around 13 at the moment, I want limit this thread only to problems with lift distribution, and wing tip stalls problem, I want exclude problems with pitching moment at the stall for swept high AR wings, and eventually stability issues.
Seb
Last edited: