During which phase does the jet engine produce thrust?

The jet engine produces thrust during all phases of its operation, which includes the compression phase, combustion phase, and exhaust phase.

In the compression phase, the engine compresses incoming air, increasing its pressure and temperature. While this phase itself allows for optimal combustion in the next phase, it does not generate thrust directly.

During the combustion phase, fuel is injected into the high-pressure air, and the mixture is ignited, producing a significant increase in temperature and pressure. The rapid expansion of the combustion gases creates a high-speed jet of exhaust that effectively contributes to producing thrust.

In the exhaust phase, the high-speed gases exit the engine through the turbine and nozzle. The reaction force generated by the expulsion of these gases pushes the engine—and consequently the aircraft—forward, creating thrust.

Since thrust generation is a result of the overall functioning of the engine throughout these phases, this understanding leads to the conclusion that all three phases contribute through their unique roles in the operation of a jet engine.