Question

At what point circulation between two material points in the sheet remains conserved.

(a) Zero

(b) One

(c) Greater than zero

(d) Less than zero

I have been asked this question in a job interview.

I'm obligated to ask this question of The Vortex Sheet topic in section Incompressible Flow over Airfoils of Aerodynamics

Answer 1

Correct option is (a) Zero

Explanation: Kelvin’s circulation theorem, is the absence of external forces on the sheet, the circulation between any two material points in the sheet remains conserved at zero. The equation of motion of the sheet can be rewritten in terms of circulation and by a change of variable.