Which of the following are the principle factors that affect the performance of a gas turbine compressor?

Correct Answer: Option C — Pressure ratio, air flow, rotational speed.

Compressor performance is defined by the relationship between pressure ratio, mass air flow, and rotational speed. These three variables dictate the compressor's operating point on its characteristic map. Deviations in these parameters can lead to aerodynamic instabilities, such as compressor stall or surge, which threaten the structural integrity of the engine.