Altitude investigation of thrust augmentation using water-alcohol injection into the combustion chambers of an axial-flow turbojet engine

Jansen, E. T., Renas, P. E.
naca-rm-e52l12
1953


An investigation was conducted in an altitude test chamber using water-alcohol injection into the combustion chambers of an axial-flow turbojet engine. Data were obtained at a flight Mach number of 0.8 for a range of altitudes from 30,000 to 50,000 feet over a range of liquid-air ratios from 0 to 0.10 and for a range of exhaust-nozzle areas from 100 percent to 93.7 percent of the standard nozzle area. Employing a continuously variable-area exhaust nozzle and operating at limiting turbine-outlet temperature, net thrust augmentation ratios of 1.25, 1.23, and 1.21 were obtained at a liquid-air ratio of 0.10 for altitudes of 30,000, 40,000, and 50,000 feet, respectively. Operation with the standard nozzle area and with a liquid-air ratio of 0.10 resulted in a variance of net thrust from 1.14 to 1.195 as the altitude was increased from 30,000 to 50,000 feet. The use of 10,000 gallons of water-alcohol mixture in 7.5 hours of engine running time resulted in no noticeable engine structural deterioriation.

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