Page 30 - The Jet Engine

Compressors

Fig. 3-1 A typical centrifugal flow compressor.

centrifugal compressor of the same frontal area and which in turn leads to improved specific fuel
can be designed to attain much higher pressure consumption for a given thrust, ref. fig. 3-2.
ratios. Since the air flow is an important factor in
determining the amount of thrust, this means the
axial compressor engine will also give more thrust for
the same frontal area. This, plus the ability to
increase the pressure ratio by addition of extra
stages, has led to the adoption of axial compressors
in most engine designs. However, the centrifugal
compressor is still favoured for smaller engines
where its simplicity and ruggedness outweigh any
other disadvantages.
4. The trend to high pressure ratios which has
favoured the adoption of axial compressors is Fig. 3-2 Specific fuel consumption and
because of the improved efficiency that results, pressure ratio.

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