Geared turbofan gas turbine engine architecture
A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.
1. A gas turbine engine comprising:
a fan section including less than 18 fan blades;
a gear train;
a compressor section;
a combustor in fluid communication with the compressor section;
a turbine section in fluid communication with the combustor and including a fan drive turbine and a second turbine, the fan drive turbine driving a fan rotor through the gear train wherein:
the fan drive turbine includes at least one rotor having a bore radius (R), and a live rim radius (r 1 ), and a ratio of r 1 /R is between 2.00 and 2.30, and at least one rotor having a bore width (W) and a live rim radius (r 2 ) and a ratio of r 2 /W is between 4.65 and 5.55.
2. The gas turbine engine set forth in claim 1 , wherein the at least one rotor with a ratio r 1 /R between 2.00 and 2.30 is the same rotor as the at least one rotor with a ratio of r 2 /W between 4.65 and 5.55.
3. The gas turbine engine set forth in claim 1 , wherein the second turbine is a two stage turbine.
4. The gas turbine engine set forth in claim 3 , wherein the gear train is a planetary gear system.
5. The gas turbine engine set forth in claim 4 , wherein the fan drive turbine has a first exit area and is configured to rotate at a first speed, the second turbine has a second exit area and is configured to rotate at a second speed, which is faster than the first speed, said first and second speeds being redline speeds, wherein a first performance quantity is defined as the product of the first speed squared and the first area, a second performance quantity is defined as the product of the second speed squared and the second area, and a performance ratio of the first performance quantity to the second performance quantity is greater than or equal to 0.8 and less than or equal to 1.5.
6. The gas turbine engine set forth in claim 5 , wherein the ratio of r 1 /R is between 2.00 and 2.25.
7. The gas turbine engine as set forth in claim 1 , wherein the gas turbine engine has a power density defined as Sea Level Takeoff Thrust provided by the engine in lbf divided by a volume of the turbine section in in 3 and the power density being greater than 1.5 lbf/in 3 and less than 4.5 lbf/in 3 .
8. The gas turbine engine as set forth in claim 7 , wherein said power density being greater than or equal to 2.0 lbf/in 3 .
9. The gas turbine engine as set forth in claim 8 , wherein the power density being greater than 3.0 lbf/in 3 .
10. The gas turbine engine as set forth in claim 9 , wherein said power density being greater than 4.0 lbf/in 3 .
11. The gas turbine engine set forth in claim 1 , wherein the gear train is a planetary gear system, the fan drive turbine has a first exit area and is configured to rotate at a first speed, the second turbine has a second exit area and is configured to rotate at a second speed, which is faster than the first speed, said first and second speeds being redline speeds, and a first performance quantity is defined as the product of the first speed squared and the first area, a second performance quantity is defined as the product of the second speed squared and the second area, and a performance ratio of the first performance quantity to the second performance quantity is greater than or equal to 0.8 and less than or equal to 1.5.
12. A gas turbine engine comprising:
a fan section including a number of fan blades;
a gear train;
a compressor section;
a combustor in fluid communication with the compressor section;
a turbine section in fluid communication with the combustor and the turbine section including a fan drive turbine driving a fan rotor through the gear train and a second turbine, wherein:
the fan drive turbine includes at least one rotor having a bore radius (R), and a live rim radius (r 1 ), and a ratio of r 1 /R is between 2.00 and 2.30, and at least one rotor having a bore width (W) and a live rim radius (r 2 ) and a ratio of r 2 /W is between 4.65 and 5.55;
the fan drive turbine has a number of fan drive turbine stages, and a ratio between the number of fan blades and the number of fan drive turbine stages is between 2.5 and 8.5; and
the fan drive turbine has a first exit area and is configured to rotate at a first speed, the second turbine has a second exit area and is configured to rotate at a second speed, which is faster than the first speed, said first and second speeds being redline speeds, and a first performance quantity is defined as the product of the first speed squared and the first area, a second performance quantity is defined as the product of the second speed squared and the second area, and a performance ratio of the first performance quantity to the second performance quantity is greater than or equal to 0.8 and less than or equal to 1.5.
13. The gas turbine engine set forth in claim 12 , wherein the second turbine is a two stage turbine.
14. The gas turbine engine set forth in claim 13 , wherein the number of fan blades is less than 18 fan blades.
15. The gas turbine engine set forth in claim 14 , wherein the at least one rotor with a ratio r 1 /R between 2.00 and 2.30 is the same rotor as the at least one rotor with a ratio of r 2 /W between 4.65 and 5.55.
16. The gas turbine engine set forth in claim 14 , wherein the gas turbine engine has a power density defined as Sea Level Takeoff Thrust provided by the engine in lbf divided by a volume of the turbine section in in 3 and the power density being greater than 1.5 lbf/in 3 and less than 4.5 lbf/in 3 .
17. The gas turbine engine as set forth in claim 16 , wherein said power density being greater than or equal to 2.0 lbf/in 3 .
18. The gas turbine engine as set forth in claim 17 , wherein the power density being greater than 3.0 lbf/in 3 .
19. The gas turbine engine as set forth in claim 18 , wherein said power density being greater than 4.0 lbf/in 3 .
20. The gas turbine engine set forth in claim 12 , wherein the at least one rotor with a ratio r 1 /R between 2.00 and 2.30 is the same rotor as the at least one rotor with a ratio of r 2 /W between 4.65 and 5.55.
21. The gas turbine engine set forth in claim 12 , wherein the number of fan blades is less than 18 fan blades.
22. A gas turbine engine comprising:
a fan section including a number of fan blades;
a gear train;
a compressor section;
a combustor in fluid communication with the compressor section;
a turbine section in fluid communication with the combustor and including a fan drive turbine and a second turbine, the fan drive turbine driving a fan rotor through the gear train wherein:
the fan drive turbine includes at least one rotor having a bore radius (R), and a live rim radius (r 1 ), and a ratio of r 1 /R is between 2.00 and 2.25, and at least one rotor having a bore width (W) and a live rim radius (r 2 ) and a ratio of r 2 /W is between 4.65 and 5.55; and
the fan drive turbine has a number of fan drive turbine stages, and a ratio between the number of fan blades and the number of fan drive turbine stages is between 2.5 and 8.5.
23. The gas turbine engine set forth in claim 22 , wherein the number of fan blades is less than 18 fan blades.
24. The gas turbine engine set forth in claim 22 , wherein the number of fan blades is less than 18 fan blades, the second turbine is a two stage turbine, and the gear train is a planetary gear system.
25. The gas turbine engine set forth in claim 22 , wherein the number of fan blades is less than 18 fan blades, the second turbine is a two stage turbine, and the gear train is a planetary gear system.
26. The gas turbine engine set forth in claim 22 , wherein the at least one rotor with a ratio r 1 /R between 2.00 and 2.30 is the same rotor as the at least one rotor with a ratio of r 2 /W between 4.65 and 5.55.
27. The gas turbine engine set forth in claim 22 , wherein the ratio of r 2 /W is between 4.75 and 5.50.
28. The gas turbine engine set forth in claim 22 , wherein the gas turbine engine has a power density defined as Sea Level Takeoff Thrust provided by the engine in lbf divided by a volume of the turbine section in in 3 and the power density being greater than 1.5 lbf/in 3 and less than 4.5 lbf/in 3 .
29. The gas turbine engine as set forth in claim 28 , wherein the power density being greater than 3.0 lbf/in 3 .
30. The gas turbine engine as set forth in claim 29 , wherein said power density being greater than 4.0 lbf/in 3 .