Centrifugal compressors are stronger than axial compressors. The impellers of centrifugal compressors are stronger that the thin blades of the axial compressor. The small stator and rotor blades at the back of the compressor are especially fragile and susceptible to damage from foreign objects. Centrifugal compressors are also simpler and less expensive to manufacture. An axial compressor may have over 1000 blades and stator vanes; furthermore, close fits between its parts are required for efficient operation. Axial compressors are more sensitive to changes in air flow rate and rotational speed and have a narrower range of operating conditions. Changes in air flow rate and rotational speed can lead to rapid drop in efficiency. This also has a negative effect on the part load performance of the compressor and gas turbine.
On the other hand, in practically all applications for gas turbines, axial compressors are used because of their advantages. Axial compressors are more efficient than centrifugal compressors. It ischeaper to manufacture a centrifugal compressor, but the cost savings is lost from the decreased efficiency. Centrifugal compressors have a larger diameter, increasing space requirements and frontal area. Given a centrifugal compressor and an axial compressor with the same frontal area, the axial compressor will consume more air; therefore, a higher pressure ratio and more output power can be produced.
Centrifugal compressors are not as adaptable to multi-staging. Most of the centrifugal gas turbines ever made used a maximum of two stages. A centrifugal compressor is the best option to use for small engines when the application requires strength and simplicity, but a lower pressure ratio and other disadvantages can be tolerated. Centrifugal compressors are often used for the small engines in auxiliary power units.