What is the main purpose of primary air in the combustion chamber?

The main purpose of primary air in the combustion chamber is to enhance combustion. In a turbine engine, primary air is part of the air-fuel mixture that enters the combustion chamber. This air is necessary for the oxidation of the fuel, which is a crucial chemical reaction for producing the high-temperature gases that drive the turbine.

When primary air blends with the fuel, it ensures there is an adequate supply of oxygen for the combustion process. This combustion enhancement leads to a more efficient and stable burning of the fuel, generating the thrust required for the engine operation. Proper mixing of air and fuel allows for a more controlled and complete combustion, contributing to the engine's overall performance and efficiency.

While primary air does help in some cooling of the combustion chamber components, and has a role in fuel injection, its primary role remains focused on supporting the combustion process itself.