Overall engine efficiency rating for turbomachine engines
View Patent ↗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 2.0-4.0.
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, wherein the low-pressure turbine is configured to rotate at a rotational speed of 2,500 to 15,000 rpm at a cruise flight condition;
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.
2. The turbomachine engine of claim 1 , wherein the low-pressure turbine is configured to rotate at a rotational speed of 5,000 to 10,000 rpm at the cruise flight condition.
3. The turbomachine engine of claim 1 , wherein the fan assembly comprises 8-20 fan blades.
4. The turbomachine engine of claim 1 , wherein the D is within a range of 84-120 inches.
5. The turbomachine engine of claim 1 , the fan assembly can be configured to rotate at a rotational speed of 700-1500 rpm at the cruise flight condition.
6. The turbomachine engine of claim 1 , the fan assembly can be configured to rotate at a rotational speed of 850-1350 rpm at the cruise flight condition.
7. 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, wherein wherein the low-pressure turbine is configured to rotate at a rotational speed of 2,500 to 15,000 rpm at a cruise flight condition;
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 0.1 GR 1.5 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.
8. The turbomachine engine of claim 7 , wherein the low-pressure turbine is configured to rotate at a rotational speed of 5,000 to 10,000 rpm at the cruise flight condition.
9. The turbomachine engine of claim 7 , wherein the fan assembly comprises 8-20 fan blades.
10. The turbomachine engine of claim 7 , wherein the D is within a range of 84-120 inches.
11. The turbomachine engine of claim 7 , the fan assembly can be configured to rotate at a rotational speed of 700-1500 rpm at the cruise flight condition.
12. The turbomachine engine of claim 7 , the fan assembly can be configured to rotate at a rotational speed of 850-1350 rpm at the cruise flight condition.
13. The turbomachine engine of claim 7 , wherein the fan assembly comprises 12-18 fan blades, and wherein the core engine further comprises:
a low-pressure compressor comprising 1-8 stages; and
a high-pressure compressor comprising 8-15 stages.
14. The turbomachine engine of claim 7 , wherein the fan assembly comprises 12-18 fan blades, and wherein the core engine further comprises:
a low-pressure compressor comprising 1-2 stages;
a high-pressure compressor comprising 8-11 stages; and
a high-pressure turbine comprising 2 stages.