Centrifugal flow compressor is defined as what?

• A. An impeller-shaped device that receives air at its center and slings the air outward at high velocity into a diffuser for increased pressure.
• B. A turbine-driven device that slows air for cooling.
• C. An axial flow device that compresses air along the axis.
• D. A diffuser at the exit of a ram air scoop.

Answer: (A)

A centrifugal flow compressor uses a rapidly spinning impeller to move air outward from the center toward a diffuser, converting that outward speed into higher pressure. Air enters at the center of the impeller; the blades fling it outward to the diffuser where the high velocity is slowed, and the kinetic energy is transformed into static pressure, yielding an increased pressure output. This radial flow approach is different from axial flow compressors, which compress air as it moves along the axis through multiple stages. The other descriptions refer to a turbine for cooling or a diffuser at a ram air scoop, which are not the compressor itself, and they don’t describe the outward, centrifugal action that creates pressure rise.