Centrifugal Pump vs Reaction Turbine — Reversed Action State whether the following statement is correct: “The action of a centrifugal pump is that of a reversed reaction turbine.”

Introduction:Pumps add energy to a fluid, while turbines extract energy from a fluid. A reaction turbine and a centrifugal pump share similar flow passages and velocity triangles but operate in opposite directions of energy transfer. Recognizing this duality clarifies many performance relations and similarity laws.

Given Data / Assumptions:

• Incompressible flow; similar impeller/runner geometry.
• Loss mechanisms present but not altering the fundamental action.

Concept / Approach:In a reaction turbine, water enters the runner with high pressure/velocity and leaves with lower energy as the runner extracts work. In a centrifugal pump, the impeller does work on the water, raising its head; the velocity triangles are effectively reversed. Thus, a centrifugal pump can be regarded as a reaction turbine operating in reverse.

Step-by-Step Solution:Compare inlet/outlet triangles: turbine reduces whirl at outlet; pump increases whirl at outlet.Energy direction: turbine converts fluid energy → shaft; pump converts shaft energy → fluid.Conclude reversed action holds conceptually and kinematically.

Verification / Alternative check:Some small turbines can be driven as pumps (and vice versa) under suitable conditions, illustrating the reversibility of flow passages.

Why Other Options Are Wrong:Incorrect: contradicts standard turbomachinery theory.Shut-off or axial-only caveats: reversibility is not limited to those cases.

Common Pitfalls:Assuming impulse turbines share the same reverse equivalence; the statement is specific to reaction-type machines.

Final Answer:Correct