PERFORMANCE AND OPERATIONAL CHARACTERISTICS OF AnPYTHON TURBINE-PROPELLER ENGINE AT SIMULATED ALTITUDE CONDITIONS

摘要

The performance and operational characteristics of a Python turbine-propeller engine have been investigated over a range of engine operating conditions at simulated altitudes from 5000 to 40,000 feet in the NACA Lewis altitude wind tunnel. For the performance phase of the investi¬gation, a single cowl-inlet ram pressure ratio was maintained and inde¬pendent control of engine speed and fuel flow was used to obtain a range of power at each engine speed.nEngine performance data obtained at a given altitude could not he used to predict performance accurately at other altitudes by use of the standard air pressure and temperature generalizing factors.nSpecific fuel consumption based on shaft horsepower decreased as the shaft horsepower increased at a given engine speed. At a given altitude condition and turbine-inlet total temperature, there was an optimum engine speed at which maximum shaft horsepower was obtained. At a given engine speed and turbine-inlet total temperature, a greater portion of the total available energy was converted to propulsive power as the altitude increased.nWindmilling starts were made at altitudes up to 40,000 feet;the minimum true airspeed required for successful windmilling starts increased as the altitude was raised. In general, the engine control prevented large overshoots or undershoots of engine speed during starts, accelerations, and decelerations.