Question

Define Kutta-Joukowski theorem.

(a) Lift per unit span on the airfoil

(b) Drag per unit span on the airfoil

(c) Moment per unit span on the airfoil

(d) Thrust per unit span on the airfoil

I have been asked this question during an interview.

The above asked question is from The Kutta-Joukowski Theorem in portion Inviscid & Incompressible Flow of Aerodynamics

Answer 1

Right option is (a) Lift per unit span on the airfoil

The explanation: The Kutta-Joukowski theorem states that lift per unit span on a Two-Dimensional body, is directly propositional to the circulation around the body. It is a fundamental theorem of aerodynamics used for the calculation of the lift of an airfoil and any two-dimensional body.