Gas turbine engine with acoustic spacing of the fan blades and outlet guide vanes

Patent metadata

Field	Value
Publication number	US-12012898-B2
Application number	US-202217979992-A
Country	US
Kind code	B2
Filing date	Nov 3, 2022
Priority date	Nov 3, 2022
Publication date	Jun 18, 2024
Grant date	Jun 18, 2024

Abstract

A gas turbine engine comprises a fan, a core turbine engine coupled to the fan, a fan case housing the fan and the core turbine engine, a plurality of outlet guide vanes extending between the core turbine engine and the fan case, and an acoustic spacing. The fan comprises a plurality of fan blades that define a fan diameter and a BEAL. The fan case comprises an inlet and an inlet length between the inlet and the fan. The acoustic spacing comprises a distance between the fan and the plurality of outlet guide vanes, and in combination with the BEAL determines an acoustic spacing ratio of the gas turbine engine.

First claim

We claim:

1. A gas turbine engine comprising:
a core turbine engine comprising a low pressure turbine;
a gearbox assembly coupled to the low pressure turbine;
a fan coupled to the gearbox assembly and having a fan diameter and a plurality of fan blades with a blade solidity that is greater than or equal to 0.8 and less than or equal to 2.0;
a blade effective acoustic length (BEAL) defined as:

BEAL
=

2
⁢

c
2

S
⁡
(

1
-
rr

)

⁢

N
b

⁢

cos
⁡
(
γ
)

wherein c is a chord length of a fan blade of the plurality of fan blades, S is a span of the fan blade, rr is a radius ratio of the fan, γ is a stagger angle of the fan blade, and N b is the number of the plurality of fan blades;
a fan case that surrounds the fan, the fan case comprising an inlet disposed forward of the fan and an inlet length, wherein the inlet length defines an average distance from the inlet to the fan;
a plurality of outlet guide vanes disposed aft of the fan and extending radially between the core turbine engine and the fan case;
an acoustic spacing from the fan blade trailing edge to an outlet guide vane leading edge;
an acoustic spacing ratio (ASR) defined as:

ASR
=

1

(

Nv
Nb

)

·

As
BEAL

wherein As is the acoustic spacing, Nv is the number of the plurality of outlet guide vanes, and
wherein the ASR of the gas turbine engine is 1.4 to 3.2.

2. The gas turbine engine of claim 1 , further comprising a fan pressure ratio from 1.25 to 1.45.

3. The gas turbine engine of claim 1 , wherein the ASR is 1.5 to 3.1.

4. The gas turbine engine of claim 1 , wherein the ASR is 1.6 to 3.0.

5. The gas turbine engine of claim 1 , further comprising an inlet length ratio that is a ratio of an inlet length to a diameter of the fan blade, wherein the inlet length defines an average distance from a leading edge of the fan blade to an inlet of the fan, and
wherein the inlet length ratio is 0.15 to 0.4.

6. The gas turbine engine of claim 5 , wherein the inlet length ratio is 0.15 to 0.3.

7. The gas turbine engine of claim 1 , wherein the fan case further comprises an acoustic treatment disposed on an interior surface of the fan case.

8. The gas turbine engine of claim 7 , wherein a length of the acoustic treatment is 50% to 90% of the inlet length, the inlet length being an average distance from a leading edge of the fan blade to an inlet of the fan.

9. The gas turbine engine of claim 1 , wherein the number of the plurality of outlet guide vanes is at least twice the number of the plurality of fan blades.

10. The gas turbine engine of claim 1 , wherein the low pressure turbine comprises at least three low pressure turbine stages.

11. The gas turbine engine of claim 10 , wherein the low pressure turbine comprises at least four low pressure turbine stages.

12. The gas turbine engine of claim 1 , wherein the plurality of outlet guide vanes further comprise serrated leading edges.

13. The gas turbine engine of claim 1 , wherein the plurality of fan blades comprise composite materials that include a matrix and a plurality of fiber plies.

14. The gas turbine engine of claim 13 , wherein the plurality of fiber plies are interwoven in in-plane and out-of-plane orientations.

15. The gas turbine engine of claim 13 , wherein the plurality of fiber plies are interwoven in three or more different orientation angles.

16. The gas turbine engine of claim 1 , wherein a fan blade diameter of the fan blade is 70-80 inches.

17. The gas turbine engine of claim 1 , wherein a fan blade diameter of the fan blade is 80-95 inches.

18. The gas turbine engine of claim 1 , wherein a fan blade diameter of the fan blade is 95-105 inches.

19. The gas turbine engine of claim 1 , wherein the number of the plurality of fan blades is 14-26.

20. The gas turbine engine of claim 1 , wherein the number of the plurality of fan blades is 20-24.

21. The gas turbine engine of claim 1 , wherein the number of the plurality of fan blades is 20-22.

22. A gas turbine engine comprising:
a core turbine engine comprising a low pressure turbine;
a gearbox assembly coupled to the low pressure turbine;
a fan coupled to the gearbox assembly and having a fan diameter and a plurality of fan blades with a blade solidity that is greater than or equal to 0.8 and less than or equal to 2.0;
a fan pressure ratio from 1.25 to 1.45;
a blade effective acoustic length (BEAL) defined as:

B
⁢
E
⁢
A
⁢
L

=

2
⁢

c
2

S
⁡
(

1
-
rr

)

⁢

N
b

⁢

cos
⁡
(
γ
)

wherein c is a chord length of a fan blade of the plurality of fan blades, S is a span of the fan blade, rr is a radius ratio of the fan, γ is a stagger angle of the fan blade, and N b is the number of the plurality of fan blades;
a fan case that surrounds the fan, the fan case comprising an inlet disposed forward of the fan and an inlet length, wherein the inlet length defines an average distance from the inlet to the fan;
an inlet length ratio that is a ratio of an inlet length to a diameter of the fan blade, wherein the inlet le

Assignees

• Gen Electric

Inventors

• Miller Brandon Wayne
• Geertsema Egbert
• Sibbach Arthur W
• Hudecki Andrew
• Depuy Timothy Richard
• Schilling John C
• Worthoff Frank
• Nakano Tsuguji

Classifications

• F04D29/666

  by means of rotor construction or layout, e.g. unequal distribution of blades or vanes · CPC title

• F02C3/04 Primary

  having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F02C7/36

  Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) · CPC title

• F05D2260/40311

  of the epicyclical, planetary or differential type · CPC title