question_answer

Which of the following relations must hold for an irrotational two-dimensional flow in the \[x-y\] plane:

A) \[\frac{\partial v}{\partial y}-\frac{\partial u}{\partial x}=0\]                     

B) \[\frac{\partial u}{\partial z}-\frac{\partial v}{\partial x}=0\]

C) \[\frac{\partial w}{\partial y}-\frac{\partial v}{\partial z}=0\]                     

D) \[\frac{\partial v}{\partial x}-\frac{\partial u}{\partial y}=0\]