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US-12624662-B2 - Overall engine efficiency rating for turbomachine engines

US12624662B2US 12624662 B2US12624662 B2US 12624662B2US-12624662-B2

Abstract

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.

Inventors

  • Andrea Piazza
  • Jeffrey D. Clements

Assignees

  • GENERAL ELECTRIC COMPANY
  • GE AVIO S.R.L.

Dates

Publication Date
20260512
Application Date
20240313
Priority Date
20220131

Claims (18)

  1. 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, an output, and a gear ratio (GR), wherein the gearbox is a multi-stage gearbox, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine, and wherein the output of the gearbox is coupled to the fan assembly; 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 . 5 ⁢ 3 ⁢ 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. 2 . The turbomachine engine of claim 1 , wherein the gearbox is a two-stage gearbox.
  3. 3 . The turbomachine engine of claim 1 , further comprising a combustor disposed aft of the fan assembly and forward of the low-pressure turbine, wherein the gearbox is located forward from the combustor.
  4. 4 . The turbomachine engine of claim 1 , wherein the gearbox is a compound gearbox.
  5. 5 . The turbomachine engine of claim 4 , wherein the compound gearbox comprises one or more compound gears, wherein each of the one or more compound gears includes a first portion having a first diameter and a second portion having a second diameter, the second diameter being less than the first diameter.
  6. 6 . The turbomachine engine of claim 1 , wherein the N is exactly three rotating blade stages.
  7. 7 . The turbomachine engine of claim 1 , wherein the N is exactly four rotating blade stages.
  8. 8 . The turbomachine engine of claim 1 , wherein the N is exactly five rotating blade stages.
  9. 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, an output, and a gear ratio (GR), wherein the gearbox is a multi-stage gearbox, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine, and wherein the output of the gearbox is coupled to the fan assembly; and an overall engine efficiency rating greater than or equal to 0.1GR 1.5 and less than or equal to GR 1.5 , wherein the overall engine efficiency rating equals Q ⁢ ( D 1.56 T ) 1 . 5 ⁢ 3 ⁢ 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. 10 . The turbomachine engine of claim 9 , wherein the gearbox is a two-stage gearbox.
  11. 11 . The turbomachine engine of claim 9 , further comprising a combustor disposed aft of the fan assembly and forward of the low-pressure turbine, wherein the gearbox is located forward from the combustor.
  12. 12 . The turbomachine engine of claim 9 , wherein the gearbox is a compound gearbox.
  13. 13 . The turbomachine engine of claim 9 , wherein the N is exactly four rotating blade stages.
  14. 14 . 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, an output, and a gear ratio (GR), wherein the gearbox is a multi-stage gearbox, wherein the input of the gearbox is coupled to the low-pressure turbine of the core engine, and wherein the output of the gearbox is coupled to the fan assembly; and an overall engine efficiency rating greater within a range of 0.57-8.0, wherein the overall engine efficiency rating equals Q ⁢ ( D 1.56 T ) 1 . 5 ⁢ 3 ⁢ 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.
  15. 15 . The turbomachine engine of claim 14 , wherein the gearbox is a two-stage gearbox.
  16. 16 . The turbomachine engine of claim 14 , wherein the gearbox is a compound gearbox comprising one or more compound gears, and wherein each compound gear includes a first portion having a first diameter and a second portion having a second diameter, the second diameter being less than the first diameter.
  17. 17 . The turbomachine engine of claim 14 , 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.
  18. 18 . The turbomachine engine of claim 14 , 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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/209,689, filed Jun. 14, 2023, which is a continuation of U.S. patent application Ser. No. 17/929,542, filed Sep. 2, 2022, now U.S. Pat. No. 11,713,721, which is a continuation of U.S. patent application Ser. No. 17/694,444, filed Mar. 14, 2022, now U.S. Pat. No. 11,466,624, which claims the benefit of Italian Application No. 102022000001613, filed Jan. 31, 2022. The prior applications are incorporated by reference herein. ACKNOWLEDGMENT OF GOVERNMENT SUPPORT The project leading to this application has received funding from the Clean Sky 2 Joint Undertaking (JU) under grant agreement No. 945541. The JU receives support from the European Union's Horizon 2020 research and innovation programme and the Clean Sky 2 JU members other than the Union. FIELD This disclosure relates generally to turbomachines comprising a gearbox and particularly to geared turbofan engines. BACKGROUND A turbofan engine includes a core engine that drives a bypass fan. The bypass fan generates the majority of the thrust of the turbofan engine. The generated thrust can be used to move a payload (e.g., an aircraft). In some instances, a turbofan engine is configured as a direct drive engine. Direct drive engines are configured such that a power turbine (e.g., a low-pressure turbine) of the core engine is directly coupled to the bypass fan. As such, the power turbine and the bypass fan rotate at the same rotational speed (i.e., the same rpm). In other instances, a turbofan engine can be configured as a geared engine. Geared engines include a gearbox disposed between and interconnecting the bypass fan and power turbine of the core engine. The gearbox, for example, allows the power turbine of the core engine to rotate at a different speed than the bypass fan. Thus, the gearbox can, for example, allow the power turbine of the core engine and the bypass fan to operate at their respective rotational speeds for maximum efficiency and/or power production. Despite certain advantages, geared turbofan engines can have one or more drawbacks. For example, including a gearbox in a turbofan engine introduces additional complexity to the engine. This can, for example, make engine development and/or manufacturing significantly more difficult. As such, there is a need for improved geared turbofan engines. There is also a need for devices and methods that can be used to develop and manufacture geared turbofan engines more efficiently and/or precisely. BRIEF DESCRIPTION Aspects and advantages of the disclosed technology will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the technology disclosed in the description. Various turbomachine engines and gear assemblies are disclosed herein. The disclosed turbomachine engines comprise a gearbox. The disclosed turbomachine engines are characterized or defined by an overall engine efficiency rating. The overall engine efficiency rating equals Q⁢ (D1.56T)1.5⁢3⁢N2, where Q is a gearbox oil flow rate an inlet of the gearbox measured in gallons per minute at a max takeoff condition, D is a diameter of the fan blades measured in inches, T is a net thrust of the turbomachine engine measured in pounds force at the max takeoff condition, and N is a number of rotating blade stages of a low-pressure turbine. Values for the overall engine efficiency rating identify key engine requirements affecting the overall architecture. An engine architecture based, at least in part, on this value, can enable early optimization of major engine components, thereby benefiting the overall architecture. Thus, the overall engine efficiency rating may also be used, for example, to aid the development of the fan, gearbox, and/or low-pressure turbine in relation to other engine parameters. The overall engine efficiency rating thus provides improved turbomachine engines and/or can help simplify one or more complexities of geared turbomachine engine development. In one example, a turbomachine engine includes: 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 of 0.57-8.0, wherein the overall engine efficiency rating equals Q⁢ (D1.56T)1.5⁢3⁢N2, 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 f