US 12,123,310 B2
Gas turbine engine with idle thrust ratio
Stephen G. Pixton, South Windsor, CT (US); Gary Collopy, Vernon, CT (US); and Ozhan Turgut, South Windsor, CT (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RTX CORPORATION, Farmington, CT (US)
Filed on Oct. 4, 2023, as Appl. No. 18/480,627.
Application 18/480,627 is a continuation of application No. 17/379,202, filed on Jul. 19, 2021, granted, now 11,814,968.
Prior Publication US 2024/0240569 A1, Jul. 18, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. F01D 15/12 (2006.01); F02C 3/00 (2006.01); F02C 7/32 (2006.01)
CPC F01D 15/12 (2013.01) [F02C 3/00 (2013.01); F02C 7/32 (2013.01); F05D 2220/323 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A gas turbine engine comprising:
a propulsor section including a propulsor having a plurality of propulsor blades;
a geared architecture;
a first spool including a first shaft that interconnects a first compressor and a first turbine, wherein the first compressor includes three stages, wherein the first turbine drives the propulsor through the geared architecture such that the propulsor is rotatable at a lower speed than a speed of the first spool, wherein the first turbine includes an inlet, an outlet and a turbine pressure ratio greater than or equal to 8.0 at cruise, and wherein the turbine pressure ratio is pressure measured prior to the inlet as related to pressure at the outlet prior to an exhaust nozzle;
a second spool including a second shaft that interconnects a second compressor and a second turbine, wherein the second turbine includes two stages, and the first turbine includes a greater number of stages than the second turbine;
a first power takeoff from the first spool; and
a second power takeoff from the second spool;
wherein a second pressure ratio across the second compressor is greater than 7.0 at cruise;
wherein the gas turbine engine is rated to provide an amount of thrust at ground idle, and the gas turbine engine is rated to provide an amount of thrust at maximum takeoff, and wherein a thrust ratio is defined as a ratio of the amount of thrust at ground idle divided by the amount of thrust at maximum takeoff, the thrust ratio is less than or equal to 0.050, and ground idle is measured at static sea-level and 111 degrees Fahrenheit;
wherein a first quantity of power extracted by all aircraft accessories driven by the first power takeoff is non-zero at ground idle and a second quantity of power extracted by all aircraft accessories driven by the second power takeoff is non-zero at ground idle; and
wherein a power extraction ratio, defined as the first quantity of power extracted by all aircraft accessories driven by the first power takeoff divided by a sum of the first quantity of power and the second quantity of power, is equal to or greater than 0.90 at ground idle, and wherein the aircraft accessories perform sub-system functionality to operate an associated aircraft.