Geared turbofan arrangement with core split power ratio
View Patent ↗A propulsor section includes a propulsor having a plurality of blades rotatable about an engine longitudinal axis. A compressor section includes a low pressure compressor and a high pressure compressor. A turbine section includes a low pressure turbine that drives the propulsor through an epicyclic gear arrangement, and includes a second turbine that drives the high pressure compressor. A power ratio is provided by the combination of a first power input of the low pressure compressor and a second power input of the high pressure compressor. The power ratio is defined by the second power input divided by the first power input. The power ratio is equal to, or greater than, 1.0 and less than, or equal to, 1.4.
1. A gas turbine engine comprising:
a propulsor section including a propulsor having a plurality of blades rotatable about an engine longitudinal axis, and the propulsor having a pressure ratio of less than 1.50 across the plurality of blades alone at cruise at 0.8 Mach and 35,000 feet;
a compressor section including a low pressure compressor and a high pressure compressor;
a turbine section including a low pressure turbine that drives the propulsor through an epicyclic gear arrangement, and including a second turbine that drives the high pressure compressor; and
a power ratio provided by the combination of a first power input of the low pressure compressor and a second power input of the high pressure compressor, the power ratio defined by the second power input divided by the first power input, the power ratio being equal to, or greater than, 1.0 and less than, or equal to, 1.4.
2. The gas turbine engine as set forth in claim 1 , wherein an overall pressure ratio is provided by the combination of the low pressure compressor, the high pressure compressor and a root pressure rise of the propulsor section, and the overall pressure ratio is equal to or greater than 36.
3. The gas turbine engine as set forth in claim 2 , wherein a low corrected tip speed of the plurality of blades is less than 1150 feet per second.
4. The gas turbine engine as set forth in claim 3 , wherein the low pressure turbine includes an inlet, an outlet and a pressure ratio of greater than 5, the pressure ratio being pressure measured prior to the inlet as related to pressure at the outlet prior to an exhaust nozzle.
5. The gas turbine engine as set forth in claim 4 , wherein a gear ratio of the epicyclic gear arrangement is greater than 2.3.
6. The gas turbine engine as set forth in claim 5 , wherein the power ratio is less than or equal to 1.3.
7. The gas turbine engine as set forth in claim 6 , wherein the low pressure compressor includes a plurality of stages, and the high pressure compressor includes 6 or more stages.
8. The gas turbine engine as set forth in claim 7 , wherein the turbine section includes at least two turbine stages upstream of the low pressure turbine.
9. The gas turbine engine as set forth in claim 8 , wherein the pressure ratio of the propulsor is less than 1.45 across the plurality of blades alone at cruise at 0.8 Mach and 35,000 feet.
10. The gas turbine engine as set forth in claim 8 , wherein the gear arrangement is a planetary gear system.
11. The gas turbine engine as set forth in claim 8 , wherein the propulsor is rotatable in the same direction as the low pressure turbine.
12. The gas turbine engine as set forth in claim 8 , wherein the gear ratio is greater than 2.6.
13. The gas turbine engine as set forth in claim 2 , wherein the propulsor has a pressure ratio of less than 1.45 across the plurality of blades alone at cruise at 0.8 Mach and 35,000 feet.
14. The gas turbine engine as set forth in claim 13 , wherein the turbine section includes at least two turbine stages upstream of the low pressure turbine.
15. The gas turbine engine as set forth in claim 14 , wherein the low pressure compressor includes a plurality of stages, and the high pressure compressor includes 6 or more stages.
16. The gas turbine engine as set forth in claim 15 , wherein a gear ratio of the gear arrangement is greater than 2.3.
17. The gas turbine engine as set forth in claim 16 , wherein the low pressure compressor includes three stages.
18. The gas turbine engine as set forth in claim 17 , wherein a low corrected tip speed of the plurality of blades is less than 1150 feet per second.
19. The gas turbine engine as recited in claim 18 , wherein the low pressure turbine includes an inlet, an outlet and a pressure ratio of greater than 5, the pressure ratio being pressure measured prior to the inlet as related to pressure at the outlet prior to an exhaust nozzle.
20. The gas turbine engine as set forth in claim 19 , wherein the propulsor has a pressure ratio of less than 1.40 across the plurality of blades alone at cruise at 0.8 Mach and 35,000 feet.
21. The gas turbine engine as set forth in claim 20 , wherein the low pressure compressor includes four or more stages.
22. The gas turbine engine as set forth in claim 20 , wherein the power ratio is less than or equal to 1.3.
23. The gas turbine engine as set forth in claim 22 , wherein the gear ratio is greater than 2.6.
24. The gas turbine engine as set forth in claim 22 , wherein the power ratio is less than 1.27.
25. The gas turbine engine as set forth in claim 24 , wherein the gear arrangement is a planetary gear system.
26. The gas turbine engine as set forth in claim 25 , wherein the low pressure compressor includes four or more stages.
27. The gas turbine engine as set forth in claim 25 , wherein the gear ratio is greater than 2.9.
28. The gas turbine engine as set forth in claim 27 , wherein the plurality of blades are mounted to a disk with a characteristic density of less than 13.1 pounds per inch squared of frontal area.
29. The gas turbine engine as set forth in claim 28 , wherein the low pressure turbine includes a turbine blade made of a directionally solidified material or a turbine blade made of a single-crystal material.