Energy Efficient Engine

{{Orphan|date=August 2024}}

The Energy Efficient Engine was a program funded by NASA in the 1970s to develop technologies suitable for energy efficient turbofans. Its goal was to improve thrust specific fuel consumption by 12% compared to a GE CF6-50C.{{citation |author= Hall, Edward J. |author2= Lynn, Sean R. |author3= Heidegger, Nathan J. |author4= Delaney, Robert A. |title= Energy Efficient Engine Low Pressure Subsystem Flow Analysis |url= https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980232149.pdf |publisher= Lewis Research Center, NASA |pages= 6–7 |date= April 1998 |hdl= 2060/19980232149}} Both General Electric and Pratt & Whitney produced turbofans for the program. The GE core featured a 23:1 high-pressure (HP) ratio ten-stage HP compressor,{{Cite journal |author1=Ciepluch, Carl C. |author2=Davis, Donald Y. |author3=David E. Gray |url=http://visualmotives.com/ApolloAero/ACEE_CD_Companion/pdf/Lewis_ACEE |title=Results.of NASA's Energy Efficient Engine Program |journal=Journal of Propulsion and Power |date=1987 |volume=3 |issue=6 |pages=560–568 |doi=10.2514/3.23024 |url-status=dead |archiveurl=https://web.archive.org/web/20120426050448/http://visualmotives.com/ApolloAero/ACEE_CD_Companion/pdf/Lewis_ACEE%20Project_1_Energy_Efficient_Engine/Results%20of%20Energy%20Efficient%20Engine%20Program%20%281987%29.pdf |archivedate=2012-04-26 |url-access=subscription }} later used in the GE90 and GEnx. P&W also used a ten-stage HP compressor in their core, but it developed 14:1 pressure ratio.