Question

Which of the following is correct?

(a) the movement of fluid mass can either be along the streamlines or across them

(b) the movement of fluid mass can be along the streamlines but never across them

(c) the movement of fluid mass can never be along the streamlines but can be across them

(d) the movement of fluid mass can neither be along the streamlines or across them

I have been asked this question in a job interview.

I'd like to ask this question from Types of Flow Lines in division Kinematics of Flow and Ideal Flow of Fluid Mechanics

Answer 1

Right choice is (b) the movement of fluid mass can be along the streamlines but never across them

For explanation: A streamline is defined as an imaginary line within the flow such that the tangent at any point on it indicates the velocity at that point. Flow can only be along the velocity, never perpendicular to it. Hence, the movement of fluid mass can only be along the streamlines and never across them.