Definition: indicated power in an internal combustion engine Which term denotes the power developed inside the engine cylinder based on the pressure–volume work (before mechanical losses), as obtained from indicator diagrams or equivalent calculations?

Introduction / Context:
Engine performance is partitioned into indicated power (IP), brake power (BP), and friction power (FP). Distinguishing these helps quantify mechanical efficiency and identify loss sources.

Given Data / Assumptions:

• Indicated power is derived from in-cylinder pressure data (indicator diagram or IMEP).
• Brake power is the net shaft output measured by a dynamometer.
• Friction power = IP − BP, representing mechanical and pumping losses.

Concept / Approach:
IP reflects the thermodynamic work produced by combustion acting on the piston during a cycle. It precedes drivetrain and accessory losses. BP is always less than IP in real engines due to friction and pumping work. Therefore, the correct term for “power actually developed by the engine cylinder” is indicated power.

Step-by-Step Solution:

Verification / Alternative check:
Classic Morse test and modern in-cylinder pressure transducers provide independent pathways to estimate or measure IP.

Why Other Options Are Wrong:

“Theoretical power” is not standard terminology; “actual power” often refers to BP; “friction power” is a loss term, not developed power.

Common Pitfalls:
Confusing BMEP with IMEP; IMEP corresponds to indicated work per cycle, while BMEP relates to brake work.

Final Answer:

indicated power