Question

In a free vortex, the flow is:

• A. rotational
• B. irrotational
• C. rotational or irrotational
• D. neither rotational or irrotational

Answer 1

Answer:

B. irrotational

In a free vortex, the flow is irrotational as there is no external torque required to rotate the fluid mass. The momentof momentum is constant, i.e. vr = constant. Examples draining a bathtub or the flow of liquid through a hole in a container.