# US 10,371,051 B2 · Gas turbine engine noise reducing nose cone

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- Number: US 10,371,051 B2
- Document ID: US10371051B2
- Status: Granted
- Kind: B2
- Application number: 14/766,825
- Filed: 2014-02-13
- Published: 2016-02-04
- Granted: 2019-08-06
- Earliest claimed: 2013-03-01
- Assignees: United Technologies Corporation
- Applicants: United Technologies Corporation
- Inventors: Jonathan Gilson; Nigel David Sawyers-Abbott
- Web page: https://patentgrep.com/patent/US10371051B2

## CPC

- F02C 7/045: having provisions for noise suppression
- F01D 5/02: Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28})
- F01D 25/24: 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})
- F05D 2220/32: in gas turbines
- F05D 2220/36: specially adapted for the fan of turbofan engines
- F05D 2260/963: by Helmholtz resonators
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A fan section for a gas turbine engine includes a fan hub and a nose cone section operatively mounted to the fan hub. The nose cone section includes a noise attenuation feature.

## Claims

### Claim 1

A fan section for a gas turbine engine comprising;
a fan hub; and
a nose cone section operatively mounted to the fan hub, the nose cone section including a noise attenuation feature
comprising a fan nacelle, the nose cone section provided within the fan nacelle, the fan nacelle having an inlet, a fan arranged in a bypass flow path provided by the fan nacelle and rotatable about an axis, the fan having a diameter and a leading edge is axially recessed from the nacelle inlet an inlet length, and a ratio of the inlet length to the diameter of less than about 0.6,
wherein the noise attenuation feature includes discrete cavities in the nose cone section, providing a noise attenuation characteristic,
wherein the nose cone section includes a nose cone and the cavities are shaped in part as a neck within the nose cone, each of the cavities being in fluid communication with a secondary cavity, the neck having a smaller area than an adjoining area of the secondary cavity to provide a Helmholz resonator.

### Claim 2 (depends on 1)

The fan section according to claim 1, wherein the nose cone section includes a nose cone and a liner surrounding the nose cone, and the noise attenuation feature includes perforations defining the cavities.

### Claim 3 (depends on 2)

The fan section according to claim 2, wherein the nose cone includes an exterior surface, and the liner includes inner and outer surfaces, the inner surface secured to the exterior surface, and the cavities are provided in the liner.

### Claim 4 (depends on 2)

The fan section according to claim 2, wherein the nose cone includes a perimeter, the liner circumscribing the perimeter.

### Claim 5 (depends on 4)

The fan section according to claim 4, wherein the liner is a seamless structure about the perimeter.

### Claim 6 (depends on 1)

The fan section according to claim 1, wherein an acoustic liner is mounted on the fan nacelle upstream from the fan.

### Claim 7 (depends on 1)

The fan section according to claim 1, wherein the ratio is equal to or less than 0.4.