A gas turbine that has a regenerator between the compression and combustion sections in which exhaust gas heat energy is added to the air charge is classified as what type of engine?

Correct Answer: Option D — Semi-closed cycle engine.

A semi-closed cycle engine incorporates a regenerator or recuperator to recover waste heat from the exhaust stream. By transferring this thermal energy to the compressor discharge air before it enters the combustion chamber, the engine improves its overall thermal efficiency by reducing the fuel required to reach target turbine temperatures.