text: at very high velocity and high kinetic energy. 
  A pressure rise is produced by subsequent ex- 
  pansion in the diffuser manifold by converting 
  the kinetic energy into static pressure energy. 
  The manifold then distributes the high pres- 
  sure discharge to the combustion chambers. 
  A double entry impeller allows a given diam- 
  eter compressor to process a greater airflow. 
  The major components of the centrifugal com- 
  pressor are illustrated in figure 2.7. 
  
  from five to ten (or greater) with efficiencies 
  which cannot be approached with a multi- 
  stage centrifugal compressor. 
  
  The axial  flow compressor can provide 
  
  The centrifugal compressor can provide a 
  relatively high pressure ratio per stage but the 
  provision of more than one or two stages is 
  turbine engines. 
  rarely feasible for aircraft 
  The single stage centrifugal compressor is 
  capable of producing pressure ratios of about 
  three or four with reasonable efficiency. &es- 
  sure ratios greater than four require such high 
  impeller tip speed that compressor efficiency 
  decreases very rapidly. Since high pressure 
  ratios are necessary to achieve low fuel con- 
  the centrifugal compressor finds 
  sumption, 
  greatest application 
  the smaller engines 
  to 
  where simplicity and flexibility of operation are 
  the principal requirements rather than high 
  efficiency. 