Question

A beaker contains water up to a certain height as shown. If the water is allowed to get discharged through a small diffuser, what type of flow will it be in the pipe?

(a) steady and uniform

(b) unsteady and uniform

(c) steady and non-uniform

(d) unsteady and non-uniform

I had been asked this question in an interview for internship.

The above asked question is from Types of Fluid Flow in chapter Kinematics of Flow and Ideal Flow of Fluid Mechanics

Answer 1

The correct choice is (d) unsteady and non-uniform

To explain: The velocity in which the water is discharged with a velocity   With time as the water gets discharged,v decreases as H decreases. Hence, it will be an unsteady flow.

According to the continuity equation, ρAV =constant, where ρ= density, A= cross-sectional area of flow, V = velocity of flow. In this case, water is treated as an incompressible liquid (ρ =constant) but the nozzle has a gradually increasing diameter (A increases). At a given instant, V at the exit of the nozzle will be less than that at it’s entrance. Hence, it will be a non-uniform flow.