Mathematically, what is meant by Kelvin’s Circulation Theorem for an inviscid and incompressible flow? (For the same set of fluid elements moving in a closed curve along with the fluid).
(a) DΓ/Dt = 0
(b) γ1 ≥ Γ2, where 1 is the upstream direction
(c) Γ = -∮C1V.ds
(d) Γ = 0
The question was asked in homework.
The query is from Kelvin’s Circulation Theorem and the Starting Vortex in section Incompressible Flow over Airfoils of Aerodynamics