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
[tex]\omega =\dfrac{1}{2}\left (\dfrac{\partial v}{\partial x}-\dfrac{\partial u} {\partial x}\right)[/tex]
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 .
