Monday, October 22, 2012

Flying with tufts

On a blue thermal day, I spent some time adding whool tufts at wing/fuselage junction of my LS6. Here is the result :

The objective was to visualize flow separation in the root of LS6 glider.

Result : flow in wing fuselage junction is sensitive to aoa & aileron:flap deflection.
It can be observed in stall :
Separation occurs at lower fuselage attitude when flap increase. Tip : visualize this by looking at tail position vs horizon when separation appears.
It can be observed in normal flight :
In straight flight, separation is not visible. Very slight tuft activity on the fuselage sides.
While circling, separation occurs quite often, particularly on the wing inside turn. This is likely driven by the additionnal aerodynamic load brought by aileron offset ut of the turn to keep bank angle.

Next time :
Tufts should be applied on both sides It could be interesting to pull some G's to see what happens