Question

Which of the following hold(s) true with respect to the flow in volute casing outside the rotating impeller of a centrifugal pump?

1. Flow is Free vortex
2. Flow is Forced vortex
3. Flow is radial

• A. 1 only
• B. 2 only
• C. 3 only
• D. 1, 3

Answer 1

Answer:

A. 1 only

A centrifugal pump works on the principle of force vortex. The impeller generates velocity through rotation and the casing converts it into pressure. Inside the impeller, the flow is forced vortex, while outside the casing it is free vortex due to the absence of external torque.