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

Patent metadata

Field	Value
Publication number	US-9932933-B2
Application number	US-201314091862-A
Country	US
Kind code	B2
Filing date	Nov 27, 2013
Priority date	Dec 20, 2012
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

According to an example embodiment, a gas turbine engine assembly includes, among other things, a fan that has a plurality of fan blades. A diameter of the fan has a dimension D that is based on a dimension of the fan blades. Each fan blade has a leading edge. An inlet portion is situated forward of the fan. A length of the inlet portion has a dimension L between a location of the leading edge of at least some of the fan blades and a forward edge on the inlet portion. A dimensional relationship of L/D is between about 0.2 and about 0.45.

First claim

We claim:

1. A gas turbine engine assembly, comprising:
a 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
an inlet portion forward of the fan, a length of the inlet portion having a dimension L between a location of the leading edge of at least some of the fan blades and a forward edge on the inlet portion,
wherein a dimensional relationship of L/D is between 0.2 and 0.45.

2. The assembly of claim 1 , wherein the dimensional relationship of L/D is between 0.25 and 0.45.

3. The assembly of claim 2 , wherein the dimensional relationship of L/D is between 0.30 and 0.40.

4. The assembly of claim 2 , wherein the dimensional relationship of L/D is 0.35.

5. The assembly of claim 1 , wherein
the dimension L is different at a plurality of locations on the inlet portion;
a greatest value of L corresponds to a value of L/D that is at most 0.45; and
a smallest value of L corresponds to a value of L/D that is at least 0.20.

6. The assembly of claim 1 , wherein
the dimension L varies; and
the dimensional relationship of L/D is based on an average value of L.

7. The assembly of claim 1 , wherein
the dimension L varies between a top of the inlet portion and a bottom of the inlet portion; and
the dimensional relationship of L/D is based on a value of L near a midpoint between the top and the bottom of the inlet portion.

8. The assembly of claim 1 , wherein
the leading edges of the fan blades are in a reference plane; and
the dimension L extends along a direction that is perpendicular to the reference plane.

9. The assembly of claim 8 , wherein
the engine assembly has a central axis;
the reference plane is perpendicular to the central axis; and
the dimension L extends along a direction that is parallel to the central axis.

10. The assembly of claim 1 , wherein
the engine assembly has a central axis;
the forward edge on the inlet portion is in a first reference plane;
the leading edges of the fan blades are in a second reference plane; and
the dimension L is measured between a first location where the central axis intersects the first reference plane and a second location where the central axis intersects the second reference plane.

11. The assembly of claim 1 , wherein
the fan is configured to deliver a portion of air into a compressor section and a portion of air into a bypass duct;
a bypass ratio which is defined as a volume of air passing to the bypass duct compared to a volume of air passing into the compressor section being greater than or equal to 8; and
the fan is configured to have a pressure ratio between 1.20 and 1.50 when operating at sea level.

12. The assembly of claim 1 , wherein each of the fan blades is a swept fan blade.

13. The assembly of claim 1 , comprising
a speed change device configured to drive the fan at a speed that is less than an input speed in the speed change device wherein the speed change device is a geared architecture that defines a gear reduction ratio greater than or equal to 2.3.

14. The assembly of claim 1 , wherein
a fan blade tip speed of each of the fan blades is less than 1150 ft/second.

15. A gas turbine engine assembly, comprising:
a 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;
a geared architecture configured to drive the fan at a speed that is less than an input speed in the geared architecture;
a compressor section;
a turbine section configured to drive the compressor section and the geared architecture;
an inlet portion forward of the fan, a length of the inlet portion having a dimension L between a location of the leading edge of at least some of the fan blades and a forward edge on the inlet portion; and
wherein a dimensional relationship of L/D is between 0.2 and 0.45.

16. The gas turbine engine assembly of claim 15 , wherein
the dimension L varies; and
the dimensional relationship of L/D is based on an average value of L.

17. The gas turbine engine assembly of claim 15 , wherein
the fan is configured to deliver a portion of air into the compressor section, and a portion of air into a bypass duct;
a bypass ratio between a volume of air passing to the bypass duct and a volume of air passing into the compressor section is greater than or equal to 8; and
the fan is configured to have a pressure ratio less than 1.50 when operating at sea level.

18. The gas turbine engine assembly of claim 15 , wherein
the geared architecture defines a gear reduction ratio greater than or equal to 2.3.

19. The gas turbine engine assembly of claim 15 , wherein
each of the fan blades is a swept fan blade.

Assignees

• United Technologies Corp

Inventors

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

Classifications

• F05D2240/303

  related to the leading edge of a rotor blade · CPC title

• F02K3/068 Primary

  being characterised by a short axial length relative to the diameter · CPC title

• F05D2260/40311

  of the epicyclical, planetary or differential type · CPC title

• F01D25/24

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title

• F02C7/04

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