Aircraft propulsion system with asymmetric exhaust assembly

Patent metadata

Field	Value
Publication number	US-2025215840-A1
Application number	US-202318400441-A
Country	US
Kind code	A1
Filing date	Dec 29, 2023
Priority date	Dec 29, 2023
Publication date	Jul 3, 2025
Grant date	—

Abstract

An aircraft system includes a propulsion system. The propulsion system includes a turbofan engine, a nacelle and a bypass flowpath. The turbofan engine includes a fan rotor and an engine core configured to drive rotation of the fan rotor about an axis. The nacelle houses the turbofan engine and includes an outer structure. The outer structure extends axially from a leading edge to a trailing edge. The leading edge is disposed at an airflow inlet into the propulsion system. The trailing edge is disposed at an airflow exhaust from the bypass flowpath. An axial distance from the fan rotor to the trailing edge decreases as the trailing edge extends at least one-hundred and twenty degrees circumferentially about the axis. The bypass flowpath is disposed downstream of the fan rotor and radially outboard of the engine core. The bypass flowpath extends axially within the propulsion system to the airflow exhaust.

First claim

What is claimed is:

1 . An aircraft system, comprising:
a propulsion system including a turbofan engine, a nacelle and a bypass flowpath; the turbofan engine including a fan rotor and an engine core configured to drive rotation of the fan rotor about an axis; the nacelle housing the turbofan engine and comprising an outer structure, the outer structure extending axially from a leading edge to a trailing edge, the leading edge disposed at an airflow inlet into the propulsion system, and the trailing edge disposed at an airflow exhaust from the bypass flowpath, wherein an axial distance from the fan rotor to the trailing edge decreases as the trailing edge extends at least one-hundred and twenty degrees circumferentially about the axis; and the bypass flowpath disposed downstream of the fan rotor and radially outboard of the engine core, and the bypass flowpath extending axially within the propulsion system to the airflow exhaust.

2 . The aircraft system of claim 1 , wherein the axial distance from the fan rotor to the trailing edge decreases as the trailing edge extends at least one-hundred and fifty degrees circumferentially about the axis.

3 . The aircraft system of claim 1 , wherein
a first section of the outer structure is diametrically opposite a second section of the outer structure; and a first value of the axial distance at the first section of the outer structure is equal to or greater than one and one-half times a second value of the axial distance at the second section of the outer structure.

4 . The aircraft system of claim 3 , wherein the first value of the axial distance at the first section of the outer structure is equal to or greater than two times the second value of the axial distance at the second section of the outer structure.

5 . The aircraft system of claim 1 , further comprising:
an airframe comprising an airframe component; the propulsion system connected to the airframe component at a first section of the outer structure, the first section of the outer structure diametrically opposite a second section of the outer structure, and a first value of the axial distance at the first section of the outer structure greater than a second value of the axial distance at the second section of the outer structure.

6 . The aircraft system of claim 5 , wherein the propulsion system is further connected to the airframe component at a gravitational top side of the airframe component.

7 . The aircraft system of claim 1 , further comprising:
an airframe comprising an airframe component; the propulsion system connected to the airframe component at a second section of the outer structure, a first section of the outer structure diametrically opposite the second section of the outer structure, and a first value of the axial distance at the first section of the outer structure greater than a second value of the axial distance at the second section of the outer structure.

8 . The aircraft system of claim 1 , wherein
the turbofan engine further includes a fan case and a guide vane structure; the fan case axially overlaps and extends circumferentially around the fan rotor and the guide vane structure; and the guide vane structure includes a plurality of guide vanes arranged circumferentially about the axis, the plurality of guide vanes include a first guide vane, a second guide vane and a third guide vane disposed circumferentially between and next to the first guide vane and the second guide vane, the first guide vane is circumferentially spaced from the third guide vane by a first circumferential distance, and the second guide vane is circumferentially spaced from the third guide vane by a second circumferential distance that is different than the first circumferential distance.

9 . The aircraft system of claim 1 , wherein
the turbofan engine further includes a fan case and a guide vane structure; the fan case axially overlaps and extends circumferentially around the fan rotor and the guide vane structure; and the guide vane structure includes a plurality of guide vanes arranged circumferentially about the axis, the plurality of guide vanes include a first guide vane, a second guide vane and a third guide vane disposed circumferentially between and next to the first guide vane and the second guide vane, the first guide vane is circumferentially spaced from the third guide vane by a first circumferential distance, and the second guide vane is circumferentially spaced from the third guide vane by a second circumferential distance that is equal to the first circumferential distance.

10 . The aircraft system of claim 1 , wherein
the turbofan engine further includes a fan case and a guide vane structure; the fan case axially overlaps and extends circumferentially around the fan rotor and the guide vane structure; the guide vane structure includes a plurality of guide vanes arranged circumferentially about the axis in a first sector and a second sector; a first set of the plurality of guide vanes in the first sector are equispaced circumferentially about the axis; and a second set of the plurality of guide vanes in the second sector are non-equispaced circumferentially about the axis.

11 . The aircraft system of claim 10 , wherein at least one of the first sector or the second sector is semi-circular.

12 . The aircraft system of claim 1 , wherein the propulsion system further includes a lobed mixer configured to mix bypass air exhausted from the bypass flowpath with combustion products exhausted from the engine core.

13 . The aircraft system of claim 1 , wherein
the turbofan engine further includes a plurality of guide vanes disposed within the bypass flowpath and arranged circumferentially about the axis; and the propulsion system further includes a lobed mixer configured with a plurality of mixer lobes, and each of the plurality of mixer lobes is circumferentially aligned with a respective one of the plurality of guide vanes.

14 . The aircraft system of claim 13 , wherein a quantity of the plurality of guide vanes is greater than a quantity of the plurality of mixer lobes.

15 . The aircraft system of claim 1 , further comprising:
a fuselage of a blended wing body aircraft; the propulsion system mounted to the fuselage.

16 . An aircraft system, comprising:
a propulsion system including an aircraft engine, a flowpath and a nacelle; the aircraft engine comprising a propulsor rotor, and the propulsor rotor rotatable about an axis and configured to propel air through the flowpath to an airflow exhaust; and the nacelle housing the aircraft engine and comprising an outer structure with a centerline coaxial with the axis, the outer structure extending axially from a leading edge to a trailing edge, the leading edge disposed at an airflow inlet into the propulsion system, and the trailing edge disposed at the airflow exhaust, wherein at least a section of the trailing edge is angularly offset from the centerline by an acute angle when viewed in a reference plane parallel with the centerline.

17 . The aircraft system of claim 16 , wherein at least a portion of the trailing edge is curved when viewed in the reference plane.

18 . The aircraft system of claim 16 , wherein
the propulsor rotor is a fan rotor; and the flowpath is radially outboard of and bypasses a core of the aircraft engine which powers operation of the fan rotor.

19 . An aircraft system, comprising:
a propulsion system including a turbine engine, an inner flowpath, an outer flowpath and an arcuate lobed mix

Assignees

• Rtx Corp

Inventors

• Kupratis Daniel B
• Hanrahan Paul R
• Mylrea Benjamin T

Classifications

• B64C2039/105

  of blended wing body type · CPC title

• B64D27/20

  within, or attached to, fuselages · CPC title

• B64D33/04

  of exhaust outlets or jet pipes · CPC title

• F02K1/44 Primary

  Nozzles having means, e.g. a shield, reducing sound radiation in a specified direction (F02K1/40 takes precedence) · CPC title

• F02K1/52

  Nozzles specially constructed for positioning adjacent to another nozzle or to a fixed member, e.g. fairing · CPC title