Investigation of turbines suitable for use in a turbojet engine with high compressor pressure ratio and low compressor tip-speed II : velocity-diagram study of turbine for engine operation with constant exhaust-nozzle area

Davison, Elmer H., English, Robert E.
naca-rm-e52d14
1952


The range of application of two-stage turbines to driving single-spool compressors was studied by investigating whether or not a two-stage turbine with frontal area no larger than that of the compressor could be satisfactorily designed to drive a particular compressor for engine operation with constant exhaust nozzle area. It was concluded that for the purpose of driving a single-spool compressor as part of a turbojet engine, a two-stage turbine no larger in frontal area than the compressor can be satisfactorily designed within conventional turbine aerodynamic limits provided that the following conditions are satisfied: (1) The engine is operated with constant exhaust-nozzle area, and (2) the compressor has characteristics within the following range: (a) equivalent air flow per unit frontal area less than or equal to 25.8 pounds per square foot-second, (b) equivalent tip speed greater than or equal to 892 feet per second, and (c) equivalent work input less than or equal to 131 Btu per pound.

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