Does a fluid with velocity $q =\left (z-\frac{2x}{r},2y-3z-\frac{2y}{r},x-3y-\frac{2z}{r}\right)$ posses vorticity? What is the circulation in the circle $x^2+y^2 = 9$, $z =0$ ?
where $r^2=(x^2 + y^2 + z^2)$
PS: This question has been asked already but I wanted to know the concept behind it. I am getting Vortex vector as zero vector. Does vorticity means vortex vector is zero ?
And what is the difference in circulation and vorticity ? Shouldn't the circulation be also zero here as vortex vector is zero ?