Chapter 23. -GAS TURBINE 



GAS PRODUCING SECTION 



POWER TURBINE SECTION 



COMPRESSOR 



GAS 



COMBUSTION PRODUCING 



CHAMBER TURBINE 



ACCESSORY 

 DRIVE 



147.138 



Figure 23-4.— Gas turbine engine with single-spool axial-flow compressor. 



disadvantages of the axial-flow compressor 

 include difficulty of manufacture, high initial 

 cost, and relatively great weight. 



147.139 

 Figure 23-5.— Single-spool axial-flow 

 compressor. 



The advantages of the centrifugal compressor 

 include a high pressure rise per stage, simplicity 

 of manufacture, low initial cost, and relatively 

 light weight. The disadvantages of the centrifugal 

 compressor include the need for a relatively 

 large frontal area for a given air flow and the 

 difficulty of using two or more stages because 

 of losses that would occur between the stages. 



Combustion Chamber 



The combustion chamber is the component 

 in which the fuel-air mixture is burned. The 

 combustion chamber consists of a casing, aper- 

 forated inner shell, a fuel nozzle, and a device 

 for initial ignition. The number of combustion 

 chambers used in a gas turbine engine varies 

 widely; as few as one and as many as sixteen 

 combustion chambers have been used in one gas 

 turbine engine. 



The combustion chamber is the most efficient 

 component of a gas turbine engine. Efficiencies 

 between 95 and 98 percent can be obtained over a 

 wide operating range. To produce such efficien- 

 cies, combustion chambers are designed to oper- 

 ate with low pressure losses, high combustion 



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