SpaceX Starship
This is how a full-flow staged combustion cycle engine works. First, liquid methane and oxygen flow into the engine's turbopumps. The turbopumps increase the liquids' pressure. Then, the methane and oxygen evaporate into hot gases in two preburners. One preburner gets more methane, and another gets more oxygen. The gas then turns the turbines and turbopumps by a shaft. These spinning turbines and turbopumps pump more propellant to the engine. This hot and mixed gas is then burned in a combustion chamber. Finally, the engine nozzle directs the ignited gas to make thrust.