# US 12,215,591 B2 · Nacelle inlet with horizontal droop (NIHD)

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- Number: US 12,215,591 B2
- Document ID: US12215591B2
- Status: Granted
- Kind: B2
- Application number: 17/692,816
- Filed: 2022-03-11
- Published: 2022-09-15
- Granted: 2025-02-04
- Earliest claimed: 2021-03-11
- Assignees: The Boeing Company
- Applicants: The Boeing Company
- Inventors: Chen Chuck; Brian Scott Kornegay
- Web page: https://patentgrep.com/patent/US12215591B2

## CPC

- 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})
- F02C 7/04: Air intakes for gas-turbine plants or jet-propulsion plants
- B64D 29/02: associated with wings
- B64C 7/02: Nacelles
- F05D 2220/323: for aircraft propulsion, e.g. jet engines
- F05D 2230/60: Assembly methods
- F05D 2250/314: the axes being inclined in relation to each other
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- 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)
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64C: AEROPLANES; HELICOPTERS
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

An inlet for a nacelle housing a gas turbine engine generating thrust and having an engine centerline, the inlet including a highlight comprising a leading edge of the inlet, wherein the highlight has an outboard side and an inboard side; and the outboard side is forward of the inboard side of the highlight so as to increase an airflow into the inlet and allow increased alignment of a thrust vector of the thrust with the engine centerline.

## Claims

### Claim 1

An aircraft part, comprising:
an inlet for a nacelle housing a gas turbine engine, the gas turbine engine having an engine centerline and generating a thrust having a thrust vector, the inlet further comprising:
a highlight comprising an inlet leading edge of the inlet, wherein:
the highlight has an outboard side and an inboard side; and
the outboard side is forward of the inboard side so as to increase an airflow into the inlet and allow an increased alignment of the thrust vector with the engine centerline.

### Claim 2 (depends on 1)

The aircraft part of claim 1, wherein the highlight lies in a plane inclined at an angle with respect to the engine centerline.

### Claim 3 (depends on 2)

The aircraft part of claim 2, wherein the angle is in a range of half a degree to 3 degrees.

### Claim 4 (depends on 2)

The aircraft part of claim 2, wherein the angle is equal to an engine toe angle.

### Claim 5 (depends on 4)

The aircraft part of claim 4, wherein the airflow comprises a sidewash deflection and the angle is tuned to increase an input of the sidewash deflection into the inlet.

### Claim 6 (depends on 1)

An aircraft engine comprising the aircraft part of claim 1, further comprising:
the nacelle housing the gas turbine engine and a fan inputting a portion of the airflow into the gas turbine engine, the fan comprising a hub connected to fan blades and the hub comprising a hub leading edge; and
the inlet comprising:
an inboard length comprising a first perpendicular distance from a plane, comprising the hub leading edge, to the inlet leading edge on the inboard side,
an outboard length comprising a second perpendicular distance from the plane to the inlet leading edge on the outboard side, and wherein
the outboard length is longer than the inboard length.

### Claim 7 (depends on 6)

An aircraft comprising the aircraft engine of claim 6.

### Claim 8 (depends on 7)

The aircraft of claim 7, wherein the aircraft comprises a wing and a fuselage, the aircraft further including a mount mounting the aircraft engine to at least one of the wing or the fuselage, wherein the mount mounts the aircraft engine so that the engine centerline has an engine toe angle of 1 degree or less with respect to a longitudinal axis of the fuselage.

### Claim 9 (depends on 8)

The aircraft engine of claim 8, wherein the engine centerline is parallel to the longitudinal axis of the fuselage.

### Claim 10 (depends on 8)

The aircraft engine of claim 8, wherein the airflow comprises a sidewash deflection deflected by the fuselage and an angle of inclination of the highlight with respect to the engine centerline is tuned to compensate for the sidewash deflection and match the airflow into the gas turbine engine for increased thrust in a presence of the sidewash deflection.

### Claim 11 (depends on 8)

The aircraft engine of claim 8, wherein the nacelle is symmetrical about the engine centerline aft of a predetermined position.

### Claim 12 (depends on 11)

The aircraft engine of claim 11, wherein a curvature of the nacelle is blended to increase aerodynamics of a portion of the airflow around the nacelle.

### Claim 13 (depends on 8)

The aircraft engine of claim 8, wherein the aircraft comprises a flying wing and the wing includes the fuselage.

### Claim 14 (depends on 8)

The aircraft engine of claim 8, wherein the aircraft engine is mounted to the wing.

### Claim 15

A method of making an aircraft part, comprising:
fabricating an inlet for a nacelle housing a gas turbine engine, the gas turbine engine having an engine centerline and generating a thrust having a thrust vector; wherein the inlet comprises:
a highlight comprising an inlet leading edge of the inlet, wherein:
the highlight has an outboard side and an inboard side; and
the outboard side is forward of the inboard side so as to increase an airflow into the inlet and allow an increased alignment of the thrust vector with the engine centerline.

### Claim 16 (depends on 15)

The method of claim 15, further comprising:
attaching the inlet to the nacelle or fabricating a nacelle having the inlet;
housing the gas turbine engine and a fan in the nacelle so that the fan inputs a portion of the airflow into the gas turbine engine, the fan comprising a hub connected to fan blades and the hub comprising a hub leading edge; and wherein fabricating the inlet further comprises fabricating the inlet having:
an inboard length comprising a first perpendicular distance from a plane, comprising the hub leading edge, to the inlet leading edge on the inboard side,
an outboard length comprising a second perpendicular distance from the plane to the inlet leading edge on the outboard side, and wherein the outboard length is longer than the inboard length.

### Claim 17 (depends on 16)

The method of claim 16, further comprising mounting the nacelle to an aircraft comprising a wing and a fuselage using a mount, wherein the mount mounts the nacelle so that the engine centerline has an engine toe angle of 1 degree or less with respect to a longitudinal axis of the fuselage.

### Claim 18 (depends on 15)

The method of claim 15, wherein the highlight lies in a plane inclined at an angle with respect to the engine centerline.

### Claim 19 (depends on 18)

The method of claim 18, wherein the angle is in a range of half a degree to 3 degrees.

### Claim 20 (depends on 18)

The method of claim 18, wherein the angle is equal to an engine toe angle, the airflow comprises a sidewash deflection, and the angle is tuned to increase an input of the sidewash deflection into the inlet.