FAA Powerplant Written Practice Test

Which section of a turbine engine is responsible for the proper mixing of fuel and air?

1. Intake section

2. Compression section

3. Combustion section

4. Exhaust section

The correct answer is: Combustion section

The combustion section of a turbine engine is essential for the proper mixing of fuel and air. This section follows the compression stage, where air is compressed to increase its pressure and temperature. Once the compressed air enters the combustion chamber, the fuel is injected into this high-pressure environment. In this chamber, the design allows for turbulent mixing, which is crucial for efficient combustion. The arrangement of fuel nozzles and the geometry of the chamber work together to ensure that the fuel and air intermingle thoroughly. This optimal mixing is vital as it enhances the combustion process, leading to a more efficient energy output, improved performance, and reduced emissions. The other sections, while important to the overall engine operation, do not focus specifically on the mixing of fuel and air. The intake section is primarily responsible for drawing in air, the compression section compresses the air, and the exhaust section handles the expulsion of combustion gases. Thus, it is the combustion section that plays the pivotal role in ensuring fuel and air are properly mixed before ignition occurs.