Gas turbine performance is influenced by air density. Which statement is correct?

• A. Output increases when using air of maximum density
• B. Air density has no effect on output
• C. Output decreases with higher density
• D. Cooling water requirement increases with density

Answer: (A)

Air density directly affects the mass of air the compressor can deliver. Denser air means more air mass enters per unit volume, so for the same volumetric flow, the engine takes in more oxygen. More oxygen allows more fuel to be burned in the combustor, delivering greater energy to the turbine and yielding higher shaft output. Colder air is denser, so it naturally supports higher power output because the engine can ingest more mass flow without increasing volume. That’s why the statement that output increases when using air of maximum density is correct.

The other ideas don’t fit because density does affect output, and higher density does not reduce output; cooling water needs aren’t dictated by air density in a direct, simple way.