Terminology match – blading efficiency is also called what? In steam turbine performance nomenclature, “blading efficiency” is commonly referred to as which of the following?

Introduction / Context:
Different efficiency terms in turbines capture losses at different parts of the machine. Clear terminology helps you analyze where performance is gained or lost and avoid mixing blade aerodynamics with thermodynamic stage or cycle measures.

Given Data / Assumptions:

• Focus on a blade row and the kinetic energy it receives.
• Blade-entry and blade-exit velocity triangles are known or measurable.
• Nozzle behavior and mechanical losses considered separately.

Concept / Approach:

Blading efficiency is the same concept as diagram efficiency: the ratio of work obtained from the blades to the energy supplied to them. Stage efficiency uses the isentropic heat drop for the entire stage (nozzle plus rotor) as the reference. Nozzle efficiency compares actual to isentropic velocity rise across the nozzle only. Therefore, the correct synonym for blading efficiency is diagram efficiency.

Step-by-Step Solution:

Verification / Alternative check:

Textbook definitions and solved velocity-triangle examples use η_d and “blading efficiency” synonymously.

Why Other Options Are Wrong:

Stage efficiency and nozzle efficiency reference different domains (stage-wide and nozzle-only).Mechanical efficiency covers shaft power versus internal power, not blade aerodynamics.

Common Pitfalls:

Using stage efficiency when the question demands a blades-only metric; always check what the denominator represents.

Final Answer:

diagram efficiency