Raising the air temperature entering a gas turbine compressor primarily causes the turbine's output power to do what?

• A. Increase
• B. Decrease
• C. Remain unchanged
• D. Decrease RPM

Answer: (B)

Inlet air temperature affects air density and mass flow, which controls turbine power. Warmer air is less dense, so for the same volumetric rate (and engine speed) less air mass enters the compressor per second. Since the turbine’s shaft power depends on the mass flow of air and the energy it can extract per unit mass, a decrease in mass flow reduces the total power the turbine can deliver, even though the energy per kilogram is higher with hotter air. The net effect is a reduction in turbine output power.