In the marine gas turbine engine shown in the illustration, the HP turbine 2nd stage nozzle vanes are cooled by __________. Illustration GT-0020

Correct Answer: Option C — 13th stage compressor air

Thirteenth-stage compressor air is the designated cooling medium for the high-pressure turbine second-stage nozzle vanes. This specific stage provides the necessary pressure and temperature balance to effectively cool the vanes while minimizing the impact on overall engine thermal efficiency, adhering to the LM2500's internal cooling flow design specifications.