FAA Powerplant Written Practice Test

What is the primary purpose of stator vanes in an axial flow turbine engine compressor?

1. To decrease air pressure

2. To increase air pressure

3. To regulate engine temperature

4. To reduce drag in the air stream

The correct answer is: To increase air pressure

The primary purpose of stator vanes in an axial flow turbine engine compressor is to increase air pressure. These vanes play a crucial role by guiding the airflow between the rotating blades. They are strategically designed to direct the incoming air towards the rotating blades at an optimal angle, allowing for efficient compression by the rotor blades. As the rotor blades spin, they accelerate the air and the stator vanes help to convert the kinetic energy of that moving air into increased static pressure. This process is essential for maintaining the necessary airflow and pressure conditions needed for efficient combustion in the engine. The combination of the rotors and stator vanes ensures that the air remains under control and is compressed effectively before entering the combustion chamber, enhancing overall engine performance. In contrast, other options either misrepresent the function of the vanes or address unrelated aspects of engine operation. Therefore, the correct answer emphasizes the vital role that stator vanes play in the compression process, ultimately leading to an increase in air pressure within the engine.