Question

Which type of flow has no rotation of fluid elements about their center of mass?

• A. Rotational flow
• B. Irrotational flow
• C. Uniform flow
• D. Non-uniform flow

Hint:

Rotational vs. Irrotational Flow. Irrotational flow means fluid particles do not rotate about their own axes as they move; vorticity is zero. Rotational flow involves particle rotation; vorticity is non-zero.

Answer 1

The Correct Option is B

Fluid flow can be characterized by the motion of infinitesimal fluid elements.
- If fluid elements maintain their orientation without rotating about their own center of mass as they move along streamlines, the flow is termed irrotational.
Mathematically, this corresponds to zero vorticity (\(\nabla \times \vec{V} = 0\)).
- If fluid elements rotate about their center of mass, the flow is termed rotational (non-zero vorticity).
Uniform/non-uniform flow refers to whether the velocity vector is constant or varies spatially.
The absence of rotation defines irrotational flow.