Nacelle short inlet

Patent metadata

Field	Value
Publication number	US-10724541-B2
Application number	US-201615378371-A
Country	US
Kind code	B2
Filing date	Dec 14, 2016
Priority date	Dec 31, 2015
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

A fan assembly for a gas turbine engine includes a fan including a plurality of fan blades. Each fan blade extends radially outwardly from a fan hub to a blade tip. The plurality of blade tips define a fan diameter. A nacelle surrounds the fan and defines a fan inlet upstream of the fan, relative to an airflow direction into the fan. The nacelle has a forwardmost edge defining an inlet length from the forwardmost edge to a leading edge of a fan blade of the plurality of fan blades. A ratio of inlet length to fan diameter is between 0.20 and 0.45. A nacelle inner surface defines a nacelle flowpath. The nacelle flowpath has a convex throat portion and a concave diffusion portion between the throat portion and the leading edge of the fan blade at a bottommost portion of the nacelle.

First claim

The invention claimed is:

1. A fan assembly for a gas turbine engine, comprising:
a fan including a plurality of fan blades, each fan blade extending radially outwardly from a fan hub to a blade tip, the plurality of blade tips defining a fan diameter;
a nacelle surrounding the fan and defining a fan inlet upstream of the fan, relative to an airflow direction into the fan, the nacelle having a forwardmost edge defining an inlet length from the forwardmost edge to a leading edge of a fan blade of the plurality of fan blades, a ratio of inlet length to fan diameter between 0.20 and 0.45; and
a nacelle inner surface defining a nacelle flowpath, the nacelle flowpath having a convex throat portion and a concave diffusion portion between the throat portion and the leading edge of the fan blade along a bottommost portion of the nacelle defined as a sixty circumferential degree portion of the nacelle centered on a bottom dead center of the nacelle;
wherein a first ratio of inlet length to fan diameter at a bottommost portion of the nacelle is between 0.20 and 0.45, and a second ratio of inlet length to fan diameter at a topmost portion of the nacelle is greater than the first ratio and also between 0.20 and 0.45.

2. The fan assembly of claim 1 , wherein the throat portion has a minimum throat radius measured from a fan central axis less than a maximum diffusion portion radius measured relative to the fan central axis.

3. The fan assembly of claim 1 , wherein the throat portion has a minimum throat radius measured from a fan central axis less than a blade tip radius measured relative to the fan central axis.

4. The fan assembly of claim 1 , wherein a maximum diffusion portion radius measured from a fan central axis is greater than a blade tip radius as measured relative to the central axis.

5. The fan assembly of claim 1 , wherein the fan assembly has a fan pressure ratio between 1.2 and 1.45.

6. The fan assembly of claim 1 , wherein the plurality of fan blades extend radially outwardly from a fan hub at a hub diameter, a ratio of the hub diameter to the fan diameter in the range of 0.25 to 0.45.

7. A gas turbine engine, comprising:
a turbine; and
a fan assembly operably connected to the turbine including:
a fan including a plurality of fan blades, each fan blade extending radially outwardly from a fan hub to a blade tip, the plurality of blade tips defining a fan diameter;
a nacelle surrounding the fan and defining a fan inlet upstream of the fan, relative to an airflow direction into the fan, the nacelle having a forwardmost edge defining an inlet length from the forwardmost edge to a leading edge of a fan blade of the plurality of fan blades, a ratio of inlet length to fan diameter between 0.20 and 0.45; and
a nacelle inner surface defining a nacelle flowpath, the nacelle flowpath having a convex throat portion and a concave diffusion portion between the throat portion and the leading edge of the fan blade along a bottommost portion of the nacelle defined as a sixty circumferential degree portion of the nacelle centered on a bottom dead center of the nacelle;
wherein a first ratio of inlet length to fan diameter at a bottommost portion of the nacelle is between 0.20 and 0.45, and a second ratio of inlet length to fan diameter at a topmost portion of the nacelle is greater than the first ratio and also between 0.20 and 0.45.

8. The gas turbine engine of claim 7 , wherein the throat portion has a minimum throat radius measured from a fan central axis less than a maximum diffusion portion radius measured relative to the fan central axis.

9. The gas turbine engine of claim 7 , wherein the throat portion has a minimum throat radius measured from a fan central axis less than a blade tip radius measured relative to the fan central axis.

10. The gas turbine engine of claim 7 , wherein a maximum diffusion portion radius measured from a fan central axis is greater than a blade tip radius as measured relative to the central axis.

11. The gas turbine engine of claim 7 , wherein the fan assembly has a fan pressure ratio between 1.2 and 1.45.

12. The gas turbine engine of claim 7 , wherein the plurality of fan blades extend radially outwardly from a fan hub at a hub diameter, a ratio of the hub diameter to the fan diameter in the range of 0.25 to 0.45.

13. The gas turbine engine of claim 7 , further comprising a spinner disposed at a central fan axis further defining the nacelle flowpath between the spinner and the nacelle inner surface.

14. A nacelle for a fan of a gas turbine engine, comprising:
a forwardmost edge defining an inlet length from the forwardmost edge to a leading edge of a fan blade of a fan, a ratio of inlet length to a fan diameter between 0.20 and 0.45; and
a nacelle inner surface defining a nacelle flowpath, the nacelle flowpath having a convex throat portion and a concave diffusion portion between the throat portion and the leading edge of the fan blade along a bottommost portion of the nacelle defined as a sixty circumferential degree portion of the nacelle centered on a bottom dead center of the nacelle;
wherein a first ratio of inlet length to fan diameter at a bottommost portion of the nacelle is between 0.20 and 0.45, and a second ratio of inlet length to fan diameter at a topmost portion of the nacelle is greater than the first ratio and also between 0.20 and 0.45.

15. The nacelle of claim 14 , wherein the throat portion has a minimum throat radius measured from a fan central axis less than a maximum diffusion portion radius measured relative to the fan central axis.

16. The nacelle of claim 14 , wherein a maximum diffusion portion radius measured from a fan central axis is greater than a fan radius as measured relative to the central axis.

17. The fan assembly of claim 1 , wherein the ratio of inlet length to fan diameter is 0.20 at a bottommost portion of the nacelle.

Assignees

• United Technologies Corp

Inventors

• Qiu Yuan J
• Malecki Robert E
• Lord Wesley K

Classifications

• B64D33/02 Primary

  of combustion air intakes · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F02K3/06

  with front fan · CPC title

• B64D2033/0286

  for turbofan engines · CPC title

• F02C7/04

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