Which of the following is not an example of free vortex flow?
(a) Flow of a water through runner of a turbine
(b) Flow of liquid through a hole provided at the bottom
(c) A whirlpool in a river
(d) Flow of the liquid around a circular bend in a pipe
I had been asked this question in an interview.
The question is from Types of Motion and Vortex Flow topic in section Kinematics of Flow and Ideal Flow of Fluid Mechanics