What are the two groups of independent cabin compressors?

The two groups of independent cabin compressors are classified as positive displacement and centrifugal compressors.

Positive displacement compressors work by trapping a specific volume of air and then compressing it to a higher pressure. This is typically achieved through mechanisms such as pistons or rotors that move the air into a smaller space, effectively increasing its pressure. These compressors are known for their ability to produce high pressures at lower volumes.

On the other hand, centrifugal compressors utilize rotating blades to draw in air and increase its velocity. The fast-moving air then passes through a diffuser where its velocity is converted into pressure. This design allows for the continuous flow of air and is generally more efficient at higher flow rates compared to positive displacement compressors.

Understanding the distinctions between these two types of compressors is essential in aviation, particularly regarding their applications in cabin pressurization and environmental control systems. Each type has unique characteristics that make them suitable for different operational requirements within an aircraft.