In the two-section model of a gas turbine engine, the statements that the cold section includes the engine inlet, compressor, and turbine; and the hot section includes the combustor, diffuser, and exhaust are true. Regarding the above statements, which is true?

In the two-section model of a gas turbine engine, the statements that the cold section includes the engine inlet, compressor, and turbine; and the hot section includes the combustor, diffuser, and exhaust are true. Regarding the above statements, which is true?

• A. Only One Is True
• B. Only Two Is True
• C. Neither One Nor Two Is True
• D. Both One And Two Are True

Answer: (C)

In a two-section model, the cold section comprises the components up to the combustor—namely the engine inlet, diffuser, and compressor. The hot section starts with the combustor and includes the turbine and exhaust (sometimes the nozzle as well). The turbine is driven by the hot gases after combustion, so it belongs to the hot section, not the cold. The diffuser, on the other hand, is part of the inlet system that slows and conditions the incoming air before the compressor, so it belongs to the cold side, not the hot. Because the first statement places the turbine in the cold section, and the second statement places the diffuser in the hot section, neither statement is true. The correct choice is the one that says neither one nor two is true.

In a two-section model, the cold section comprises the components up to the combustor—namely the engine inlet, diffuser, and compressor. The hot section starts with the combustor and includes the turbine and exhaust (sometimes the nozzle as well). The turbine is driven by the hot gases after combustion, so it belongs to the hot section, not the cold. The diffuser, on the other hand, is part of the inlet system that slows and conditions the incoming air before the compressor, so it belongs to the cold side, not the hot.

Because the first statement places the turbine in the cold section, and the second statement places the diffuser in the hot section, neither statement is true. The correct choice is the one that says neither one nor two is true.