Airfoil simulation

[hannahco]

Hello, I am wanting to create morphing wing with variable camber by bending using kerf bending structures. I was wondering if anyone knows how id be able to successfully simulate this using software and which software i would use? The idea is to draw out the structure and simulate it bending and work out the airflow around the airfoil along with stress of the material at different camber variants.
Thank you

 

[btrueblood]

"using kerf bending structures." Had to google that. You mean this type of structure?:

Kerf Bending

Bend solid wood with your bare hands… and a little help from your saw.

www.woodmagazine.com

Airflow around the foil - should be a straightforward process - find the shape, and then stick the surface coordinates into one of many airfoil flow solvers (google gives several).

What is NOT straightforward is the reduced stiffness of that surface, and what it might mean to flutter and other dynamic conditions the airfoil might see.

 

[rb1957]

is there a question there ? but yes flutter (and other aeroelastic phenomena) requires it's own analysis and is much more a 3D problem (unlike 2D flow around and airfoil) and even more specifically a plane design issue (rather than here is my wing, and so there is my flutter analysis).

 

[dcascap]

To get the airfoil characteristics (CL, CD, COP, pressure distribution) use a software like Xfoil...

If the structure is very rigid you could get the pressure or forces and apply it to your structure.

If you have a quite slender, flexible wing, then you need to do an aeroelastic analysis, this is much more complex, and you need to check for flutter. To simplify you could do a steady analysis equation and solve for equilibrium (K-K_aero)x=0 with K_aero your stiffness matrix dependent on your angle of attack (which is a function of your torsion). A bit more complex, go for unsteady Theodorsen with Wagner functions, for the profile you're using.

If you want to go to a bit more accurate representation, you could use panel method with the structure in NASTRAN (using Femap for example)

 

[WKTaylor]

I think the OP is talking about in-flight camber 'warping' of a 'stock airfoil shape... by mechanical or electromechanical methods... perhaps to replace/supplement flaps or ailerons.

I suspect that even though simulated wind-tunnel SW might 'work' to validate wing airflow/moments... the real-world structural airfoil, with variable camber, might also present challenges due to aeroelastic stability issues... divergence or flutter.

 

[rb1957]

NASA had a F111 tricked out with this ... an elastic covering instead of discrete flaps ... looks like it didn't go anywhere ... possibly because the gap/slot with the discrete flap is a primary aerodynamic influence.