Analysis algorythm incomplete
XFLR5 is an analysis tool for airfoils, wings and planes
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#176 Analysis algorythm incomplete
Hi! I am creating an aircraft with an elliptical wing. The outmost profiles are rather small, so that analysis is skipping them, as "Cl could not be interpolated". I am using VLM2 method type 2 (fixed lift) .
The problem ist, that in reality the wing is still producing local lift there (although less than the required Cl), but the unstalled part of the wing would create more lift to compensate that.
Because of this, the calculated stall speed is waaaay above the real stall speed (69kt instead of expected 58kt).
Unfortunately this is a limitation of the methods implemented in xflr5.
And anyway, the assumptions used in the potential flow model are invalid when flow separation occurs, so that the results of a panel code around stall conditions will always be questionable.
Nothing to do about it.