Question

The circulation at the center for an elliptical wing distribution does not depend upon ________

(a) Lift distribution

(b) Density of fluid at center

(c) Free-stream velocity

(d) Total span length

This question was posed to me during an online interview.

This is a very interesting question from Prandtl’s Classical Lifting-Line Theory topic in chapter Flow over Airfoils over Finite Wing of Aerodynamics

Answer 1

The correct answer is (b) Density of fluid at center

For explanation: The circulation at the center for an elliptical wing distribution is dependent directly on the total lift which can be found from the lift distribution. Also, it depends upon the free-stream velocity, total span length and free-stream fluid density.