Low pressure ratio fan engine having a dimensional relationship between inlet and fan size

Patent metadata

Field	Value
Publication number	US-10301971-B2
Application number	US-201815887136-A
Country	US
Kind code	B2
Filing date	Feb 2, 2018
Priority date	Dec 20, 2012
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

According to an example embodiment, a gas turbine engine assembly includes, among other things, a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane, a geared architecture, a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan through the geared architecture, a nacelle surrounding the fan, the nacelle including an inlet portion forward of the fan, a forward edge on the inlet portion in a second reference plane, and a length of the inlet portion having a dimension L measured along an engine axis between the first reference plane and the second reference plane. A dimensional relationship of L/D is no more than 0.45.

First claim

What is claimed is:

1. A gas turbine engine assembly, comprising:
a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane;
a geared architecture;
a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan through the geared architecture;
a nacelle surrounding the fan, the nacelle including an inlet portion forward of the fan, a forward edge on the inlet portion in a second reference plane, and a length of the inlet portion having a dimension L measured along an engine axis between the first reference plane and the second reference plane;
wherein the fan delivers a portion of air into a compressor section and a portion of air into a bypass duct, and a bypass ratio of greater than 10, the bypass ratio being a ratio of a volume of air passing to the bypass duct compared to a volume of air passing into the compressor section;
wherein the fan has a pressure ratio between 1.20 and 1.50 at a cruise design point;
wherein a dimensional relationship of L/D is no more than 0.45; and
wherein the low pressure turbine includes an inlet, an outlet, and a pressure ratio of greater than 5:1.

2. The assembly of claim 1 , wherein the geared architecture defines a gear reduction ratio of greater than 2.3.

3. The assembly of claim 2 , wherein the dimensional relationship of L/D is between 0.2 and 0.45.

4. The assembly of claim 3 , wherein the high pressure turbine includes two stages.

5. The assembly of claim 4 , wherein the dimensional relationship of L/D is no less than 0.30.

6. The assembly of claim 5 , further comprising:
an inner shaft concentric with an outer shaft;
wherein the inner shaft connects the fan and a low pressure compressor to the low pressure turbine such that the inner shaft drives the fan through the geared architecture; and
wherein the outer shaft interconnects a high pressure compressor to the high pressure turbine.

7. The assembly of claim 6 , wherein the pressure ratio of the fan is less than 1.45 at the cruise design point.

8. The assembly of claim 6 , wherein the fan has a low corrected fan tip speed of less than 1150 ft/second.

9. The assembly of claim 8 , wherein the dimensional relationship of L/D is between 0.30 and 0.40.

10. The assembly of claim 8 , wherein the turbine section includes a mid-turbine frame between the high pressure turbine and the low pressure turbine.

11. The assembly of claim 10 , wherein the mid-turbine frame includes a plurality of vanes in a core airflow path defined by the turbine section.

12. The assembly of claim 11 , wherein the plurality of vanes are inlet guide vanes.

13. The assembly of claim 12 , wherein the inlet guide vanes set airflow entering the low pressure turbine during operation.

14. The assembly of claim 13 , wherein the dimensional relationship of L/D is about 0.35.

15. The assembly of claim 14 , wherein:
the second reference plane is oriented at an oblique angle relative to the engine axis; and
the oblique angle is approximately 5 degrees.

16. The assembly of claim 3 , further comprising:
an inner shaft concentric with an outer shaft;
wherein the inner shaft connects the fan and a low pressure compressor to the low pressure turbine such that the inner shaft drives the fan through the geared architecture; and
wherein the outer shaft interconnects a high pressure compressor to the high pressure turbine.

17. The assembly of claim 16 , wherein the turbine section includes a mid-turbine frame between the high pressure turbine and the low pressure turbine.

18. The assembly of claim 17 , wherein the mid-turbine frame includes a plurality of vanes in a core airflow path defined by the turbine section.

19. The assembly of claim 18 , wherein:
the plurality of vanes are inlet guide vanes; and
the inlet guide vanes set airflow entering the low pressure turbine during operation.

20. The assembly of claim 19 , wherein the mid-turbine frame supports bearing systems.

21. The assembly of claim 16 , wherein the fan has a low corrected fan tip speed of less than 1150 ft/second.

22. The assembly of claim 21 , wherein the dimensional relationship of L/D is between 0.30 and 0.40.

23. The assembly of claim 22 , wherein the pressure ratio of the fan is less than 1.45 at the cruise design point.

24. The assembly of claim 1 , wherein the dimensional relationship of L/D is between 0.2 and 0.45.

25. The assembly of claim 24 , wherein the pressure ratio of the fan is less than 1.45 at the cruise design point.

26. The assembly of claim 25 , wherein the fan has a low corrected fan tip speed of less than 1150 ft/second.

27. The assembly of claim 25 , wherein:
the turbine section includes a mid-turbine frame between the high pressure turbine and the low pressure turbine;
the mid-turbine frame supports bearing systems; and
the mid-turbine frame includes a plurality of vanes in a core airflow path defined by the turbine section.

28. The assembly of claim 27 , wherein the plurality of vanes are inlet guide vanes.

29. The assembly of claim 25 , wherein the high pressure turbine includes two stages.

30. The assembly of claim 25 , wherein the geared architecture defines a gear reduction ratio of greater than 2.3.

Assignees

• United Technologies Corp

Inventors

• Lord Wesley K
• Malecki Robert E
• Qiu Yuan J
• Rose Becky E
• Gilson Jonathan

Classifications

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F01D17/105

  by passing part of the fluid · CPC title

• F05D2250/00

  Geometry · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F02C7/04

  Air intakes for gas-turbine plants or jet-propulsion plants · CPC title