Question

Which of these equations represent vorticity?

(a) ∇.V

(b) ∇ × V

(c) ∇.V^2

(d) (∇.V) × V

I have been asked this question in exam.

The query is from Irrotational Flow in chapter Velocity Potential Equation of Aerodynamics

Answer 1

Correct option is (b) ∇ × V

The best I can explain: Vorticity represents the circulation motion of the fluid as it flows. It is given by the curl of the velocity vector (∇ × V). The curl operation determines the circulatory nature. For an irrotational flow vorticity is not equal to zero.