Question

Velocity of a fluid up to which it flows streamlined and after which its flow becomes turbulent is called:
A) superfluous velocity
B) Reynold’s velocity
C) critical velocity
D) fluid velocity

Answer 1

As the greatest velocity with which a fluid can flow through a given conduit without becoming turbulent. The speed at which a falling object reaches critical velocity is defined as the speed at which gravity and air resistance are equalised on the object.

Complete answer:
Critical velocity of a fluid is defined as the velocity up to which the fluid flow is streamlined and above which its flow becomes turbulent.
The speed and direction at which a fluid can flow through a conduit without becoming turbulent is another method of defining critical velocity. Turbulent flow is described as an irregular fluid flow with constant amplitude and direction changes. It is the polar opposite of laminar flow, which is defined as fluid movement in parallel layers with no layer disturbances.
The critical velocity of the fluid is the speed at which the liquid flow transitions from streamlined to turbulent. When the velocity of the fluid in the pipe is low, the streamlines are straight parallel lines. The streamline remains straight and parallel to the pipe wall as the fluid's velocity progressively increases. When the velocity reaches a certain point, it starts to create patterns. The critical velocity will distribute the streamlines throughout the pipe.
The sewer pipes are gradually inclined to allow gravity to operate on the fluid flow, keeping the flow non-critical. Because solid particles are present in the flow, an excess velocity of flow can induce pipe erosion, resulting in pipe damage. Pipes damaged by high-velocity fluid can be repaired utilising trenchless methods such as cured-in-place-pipe, pipe bursting, and slip lining.
Hence, the correct option is (C) critical velocity.

Note:
The water runs through the hose, increasing in velocity as it approaches the narrower nozzle. When the cross-sectional area drops, speed increases, and when the cross-sectional area increases, speed decreases. The continuity equation has resulted in this.