Approximately what percentage of the air that passes through a turbine engine is involved in cooling?

In a turbine engine, a significant portion of the air that enters the engine is used for various cooling purposes. Specifically, about 75% of the incoming air is directed toward cooling components such as turbine blades and other critical parts of the engine. This cooling air is essential because the turbine blades operate in extremely high-temperature environments and require effective cooling to maintain structural integrity and performance.

The remaining percentage of the air is involved in the combustion process, where the fuel mixture is ignited to produce thrust. The high proportion of air used for cooling underscores the importance of thermal management in turbine engines, which is crucial for ensuring reliability and efficiency in operation.