Farfield point vortex (PV) boundary condition correction
 

Hi¡¡

I am testing some 2D airfoils in fluent.

I have NASA naca 0012 validation case as reference, and they propose a mesh 500 times chord length, but I've also read some other articles and journals, and the general rule seem to be 20-30 times chord.

They talk about "farfield point vortex (PV) boundary condition correction" if you want to reduce the distance of the farfield boundary, but I don't find any option in fluent which has to do with this.

I thought 20-30 times chord is far enough for an airfoil, but now I'm not very sure, and there are two graphics in nasa validation case which show 17% error with 30 times chord. . (http://turbmodels.larc.nasa.gov/naca..._ffeffect.html)

Could anyone help me?? Thanks¡¡

Okay I just could not believe it when u said 17% error. And I went to the link and it says 0.17% error. :confused:

and FYI 15-30 chord lengths should be enough.