FAA Powerplant Written Practice Test

Which compressor type is known to have a more complex airflow path?

1. Centrifugal flow compressor

2. Axial flow compressor

3. Rotary compressor

4. Diaphragm compressor

The correct answer is: Axial flow compressor

The axial flow compressor is known for having a more complex airflow path due to its design and operation. In an axial flow compressor, air moves parallel to the axis of the rotor. The design includes a series of rotating and stationary blades, which create multiple flow passages and stages. Each stage of blades increments the pressure and velocity of the air, allowing it to be compressed efficiently. This intricate arrangement of blades and the necessity for the air to navigate through different stages contribute to the complexity of the airflow path. The airflow must smoothly transition through each rotor and stator, maintaining a specific angle and velocity to optimize performance and minimize losses. This structural complexity allows axial compressors to achieve high efficiencies at high operational speeds, especially useful in aircraft engines where space and weight are critical factors. In contrast, other types of compressors have simpler airflow paths. For example, centrifugal compressors primarily direct air outward from the center, leading to a more straightforward, radial airflow pattern. Rotary and diaphragm compressors also utilize simpler mechanisms compared to the layered, staged approach found in axial flow compressors.