Accession Number : AD0007128


Title :   Preliminary Evaluation of Turbine Performance with Variable-Area Turbine Nozzles in a Turbojet Engine


Descriptive Note : Research memo.


Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC


Personal Author(s) : Campbell, Carl E ; Welna, Henry J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/007128.pdf


Report Date : 20 May 1953


Pagination or Media Count : 40


Abstract : The performance of a two-stage turbine with variable-area first - stage turbine nozzles was determined in the NACA Lewis altitude wind tunnel over a range of simulated altitudes from 15,000 to 44,000 feet and engine speeds from 50 to 100 percent of rated speed. The variable-area turbine nozzles were found to be mechanically reliable and to have negligible leakage losses. Increasing the turbine-nozzle-throat area from 1.15 to 1.67 square feet increased the corrected turbine gas flow or effective turbine nozzle area about 10 percent. At a given corrected turbine speed and turbine speed and turbine pressure ratio, changing the turbine nozzle area from 1.30 to 1.67 square feet lowered the efficiency 3 or 4 percent. The effect of increasing the turbine nozzle area from 1.15 to 1.67 square feet (decreasing the turning angle about 7-1/2 deg) would be to lower the turbine efficiency about 5 or 6 percent.


Descriptors :   *TURBINES , ALTITUDE , ANGLES , CORRECTIONS , EFFICIENCY , ENGINES , GAS FLOW , LOSSES , NOZZLES , PERFORMANCE(ENGINEERING) , PRESSURE , RATES , RATIOS , SIMULATION , STAGING , VARIABLE AREA NOZZLES , VELOCITY , WIND TUNNELS


Subject Categories : Jet and Gas Turbine Engines


Distribution Statement : APPROVED FOR PUBLIC RELEASE