Overall engine efficiency rating for turbomachine engines
A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and an overall engine efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include a low-pressure turbine. The gearbox includes an input and an output. The input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0. The overall engine efficiency rating is within a range of 0.57-8.0.
1. A turbomachine engine comprising:
a fan assembly including a plurality of fan blades;
a vane assembly including a plurality of vanes disposed aft of the plurality of fan blades;
a core engine including a low-pressure turbine;
a gearbox including an input and an output, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, wherein the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and wherein a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0; and
an overall engine efficiency rating within a range of 0.57-8.0, wherein the overall engine efficiency rating equals
Q
(
D
1.56
T
)
1.53
N
2
,
wherein Q is a gearbox oil flow rate at an inlet of the gearbox measured in gallons per minute at a max takeoff condition, wherein D is a diameter of the fan blades measured in inches, wherein T is a net thrust of the turbomachine engine measured in pounds force at the max takeoff condition, and wherein N is a number of rotating blade stages of the low-pressure turbine.
2. The turbomachine engine of claim 1 , wherein the overall engine efficiency rating is within a range of 0.57-3.0.
3. The turbomachine engine of claim 1 , wherein the overall engine efficiency rating is within a range of 3.0-8.0.
4. The turbomachine engine of claim 1 , wherein the gear ratio is within a range of 3.25-3.75.
5. The turbomachine engine of claim 4 , wherein the overall engine efficiency rating is within a range of 0.59-7.3.
6. The turbomachine engine of claim 1 , wherein the low-pressure turbine includes exactly three stages.
7. The turbomachine engine of claim 1 , wherein the low-pressure turbine includes exactly four stages.
8. The turbomachine engine of claim 1 , wherein the low-pressure turbine includes exactly five stages.
9. A turbomachine engine comprising:
a fan assembly including a plurality of fan blades;
a vane assembly including a plurality of vanes disposed aft of the plurality of fan blades;
a core engine including a low-pressure turbine;
a gearbox including an input and an output, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, wherein the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and wherein a gear ratio (GR) of the first rotational speed to the second rotational speed is within a range of 3.2-4.0; and
an overall engine efficiency rating greater than 0.1GR 1.5 and less than GR 1.5 , wherein the overall engine efficiency rating equals
Q
(
D
1.56
T
)
1.53
N
2
,
wherein Q is a gearbox oil flow rate at an inlet of the gearbox measured in gallons per minute at a max takeoff condition, wherein D is a diameter of the fan blades measured in inches, wherein T is a net thrust of the turbomachine engine measured in pounds force at the max takeoff condition, and wherein N is a number of rotating blade stages of the low-pressure turbine.
10. The turbomachine engine of claim 9 , wherein the overall engine efficiency rating is greater than 0.35GR 1.5 and less than 0.7GR 1.5 .
11. The turbomachine engine of claim 9 , wherein the low-pressure turbine comprises exactly 3 stages.
12. The turbomachine engine of claim 9 , wherein the low-pressure turbine comprises exactly 4 stages.
13. The turbomachine engine of claim 9 , wherein the low-pressure turbine comprises exactly 5 stages.
14. The turbomachine engine of claim 9 , wherein the overall engine efficiency rating is within a range of 0.57-3.0.
15. The turbomachine engine of claim 9 , wherein the overall engine efficiency rating is within a range of 3.0-8.0.
16. The turbomachine engine of claim 9 , wherein the gear ratio is within a range of 3.25-3.75.
17. A turbomachine engine comprising:
a fan assembly including a plurality of fan blades;
a vane assembly including a plurality of vanes disposed aft of the plurality of fan blades;
a core engine including a low-pressure turbine;
a gearbox including an input and an output, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, wherein the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and wherein a gear ratio (GR) of the first rotational speed to the second rotational speed is within a range of 2.0-2.9; and
an overall engine efficiency rating greater than 0.1GR 1.5 and less than GR 1.5 , wherein the overall engine efficiency rating equals
Q
(
D
1.56
T
)
1.53
N
2
,
wherein Q is a gearbox oil flow rate at an inlet of the gearbox measured in gallons per minute at a max takeoff condition, wherein D is a diameter of the fan blades measured in inches, wherein T is a net thrust of the turbomachine engine measured in pounds force at the max takeoff condition, and wherein N is a number of rotating blade stages of the low-pressure turbine.
18. The turbomachine engine of claim 17 , wherein the overall engine efficiency rating is greater than 0.35GR 1.5 and less than 0.7GR 1.5 .
19. The turbomachine engine of claim 17 , wherein the low-pressure turbine comprises exactly 3 stages.
20. The turbomachine engine of claim 17 , wherein the low-pressure turbine comprises exactly 4 stages.
21. The turbomachine engine of claim 17 , wherein the gear ratio is within a range of 2.0-2.5.
22. The turbomachine engine of claim 17 , wherein the low-pressure turbine is a counter-rotating low-pressure compressor.
23. A turbomachine engine comprising:
a fan assembly including a plurality of fan blades;
a vane assembly including a plurality of vanes disposed aft of the plurality of fan blades;
a core engine including a low-pressure turbine;
a gearbox including an input and an output, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, wherein the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and wherein a gear ratio (GR) of the first rotational speed to the second rotational speed is within a range of 2.0-4.0; and
an overall engine efficiency rating greater than or equal to 1.9 and less than or equal to GR 1.5 , wherein the overall engine efficiency rating equals
Q
(
D
1.56
T
)
1.53
N
2
,
wherein Q is a gearbox oil flow rate at an inlet of the gearbox measured in gallons per minute at a max takeoff condition, wherein D is a diameter of the fan blades measured in inches, wherein T is a net thrust of the turbomachine engine measured in pounds force at the max takeoff condition, and wherein N is a number of rotating blade stages of the low-pressure turbine.
24. The turbomachine engine of claim 23 , wherein the overall engine efficiency rating is greater than or equal to 0.35GR 1.5 and less than or equal to 0.7GR 1.5 .
25. The turbomachine engine of claim 24 , wherein the gear ratio is within a range of 2.0-2.5.
26. The turbomachine engine of claim 24 , wherein the gear ratio is within a range of 3.2-4.0.
27. The turbomachine engine of claim 24 , wherein the gear ratio is within a range of 3.25-3.75.
28. The turbomachine engine of claim 23 , wherein the low-pressure turbine comprises 3 or 4 rotating blade stages.
29. The turbomachine engine of claim 23 , wherein the fan assembly comprises 12-18 fan blades, wherein the low-pressure turbine comprises 3-5 stages, and wherein the core engine further comprises:
a low-pressure compressor comprising 1-8 stages;
a high-pressure compressor comprising 8-15 stages; and
a high-pressure turbine comprising 1-2 stages.
30. The turbomachine engine of claim 23 , wherein the fan assembly comprises 12-18 fan blades, wherein the low-pressure turbine comprises 3-4 stages, and wherein the core engine further comprises:
a low-pressure compressor comprising 1-5 stages;
a high-pressure compressor comprising 8-10 stages; and
a high-pressure turbine comprising 2 stages.