Question

The condition of irrotationality for a two-dimensional flow is satisfied when rotation w everywhere is (less than — equal to — more than) zero.

Answer 1

Answer:

Zero.

Explanation:

Lets take velocity V is given as in 2 dimensional flow

  V=u i +v j

V=f(x,y)

u=f(x,y)

v=f(x,y)

Rotational ability ω given as

$\omega =\dfrac{1}{2}\left (\dfrac{\partial v}{\partial x}-\dfrac{\partial u} {\partial x}\right)$

If

ω=0 ,then flow will be  irrotational.

ω ≠0 ,then flow will be rotational.

So we can say that , ω will be zero every where for  irrotational  two dimensional flow .