[bafcat]

Hello,

I have a question related to wind tunnels.

What is the difference in the lift generated by a finite wing inside a closed and an open test-section wind tunnel? And respect to a hypothetical infinitely big wing tunnel?
I think that the lift in the closed wind tunnel will be the lower (due to wall interference), instead, it will be a bit higher in the open wind tunnel and the highest will be in the infinitely big open wind tunnel right?
Can someone explain to me if is it true and why?

Regards,

Thomas

[wkernkamp]

The lift will be lower, the more open the flow. Think about a wing in ground effect: It has more lift at a given angle of attack. The more the induced flow about the tip is impeded, the higher the lift.