Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Preliminary study of advanced turboprops for low energy consumption

Technical Report ·
OSTI ID:7143045

The fuel savings potential of advanced turboprops (operational about 1985) was calculated and compared with that of an advanced turbofan for use in an advanced subsonic transport. At the design point, altitude 10.67 km and Mach 0.80, turbine-inlet temperature was fixed at 1590 K while overall pressure ratio was varied from 25 to 50. The regenerative turboprop had a pressure ratio of only 10 and an 85% effective rotary heat exchanger. Variable camber propellers were used with an efficiency of 85%. The study indicated a fuel savings of 33%, a takeoff gross weight reduction of 15%, and a direct operating cost reduction of 18% was possible when turboprops were used instead of the reference turbofan at a range of 10 200 km. These reductions were 28, 11, and 14%, respectively, at a range of 5500 km. Increasing overall pressure ratio from 25 to 50 saved little fuel and slightly increased takeoff gross weight.

Research Organization:
National Aeronautics and Space Administration, Cleveland, Ohio (USA). Lewis Research Center
OSTI ID:
7143045
Report Number(s):
N-75-24739; NASA-TM-X-71740; E-8371
Country of Publication:
United States
Language:
English