Engine performance terms — power developed inside the cylinder What do we call the power actually generated by the working fluid on the piston within the engine cylinder (as obtained from the indicator diagram)?

Introduction / Context:
Different power measures are used for engines: indicated, brake, and frictional power. Knowing their meanings is necessary for testing, design, and performance evaluation.

Given Data / Assumptions:

• Mechanically measured indicator diagram (pressure–volume) or its modern equivalent.
• Steady-state operation at the test point.

Concept / Approach:
Indicated power (IP): power developed by the gas on the piston, computed from the indicated mean effective pressure (IMEP), cylinder dimensions, and speed.Brake power (BP): power available at the crankshaft as measured by a dynamometer.Frictional power (FP): the difference, FP = IP − BP, representing mechanical losses.Thus, the power asked for—the power actually generated in the cylinder—is the indicated power.

Step-by-Step Solution:

Verification / Alternative check:
In tests, BP is always less than IP; their difference trends with lubrication, speed, and load, confirming the definitions.

Why Other Options Are Wrong:

• Brake power: shaft output after losses.
• Frictional power: a loss term, not generated power.
• None/rated power: do not match the precise definition.

Common Pitfalls:
Using brake-specific fuel consumption (bsfc) with IP by mistake; mixing IMEP with BMEP.

Final Answer: