[Yur]

Dear forum members,

I'm working on a double element wing, and I would like to know if there is a way to get reliable results for a wing with a gurney?

As I know that it's not possible to simulate multi element airfoils in X-Foil, I separate them and also simulate separatly, but on some way, X-Foil doesn't get the right chord lenght. So the simulation totally fails.

I organize all coordinates in Excel, so maybe there are some tricks to do it better.


Thanks.

[truffaldino]

Why do not you fix the chord lenghth of each airfoil and change reynolds number instead?

What problem are you solving exactly? Is it a gurney flap which is separated from main airfoil? X-foil could be not a good choise for such kind of problems.

Truffaldino

[Yur]

Well is there a way to change the chord length in X-Foil? The gurney is attached to the foil, so there are no gaps.

The problem is that X-Foil thinks that the gurney flap, is the chord length and doesn't recognize the LE.
The thing I would like to know is, if there's a proper way to put in the coordinates in Excel to let X-Foil recognize the right LE and TE.

Thanks.

[truffaldino]

Originally Posted by Yur

The problem is that X-Foil thinks that the gurney flap, is the chord length and doesn't recognize the LE.
Thanks.

I have just added a 2% gurney flap to naca0012 and loaded it to x-foil: everything seems to work. Xfoil recognizes LE and TE.

Bad panelling coul be also eliminated by tiny rounding the right angle.

For sure, your coordinate loading problem can be easily fixed, but it is not the main problem with x-foil. The real problem is more fundamental: the methods X-foil uses are not fitted for analyzing gurney flaps, and results you will get could have nothing to do with reality.

X-foil is based on integral boundary methods that do not handle vorticity regions that you have at gurney flaps, corners, steps etc.

Truffaldino