Non-circular aft nacelle cowling geometry

Patent metadata

Field	Value
Publication number	US-9995180-B2
Application number	US-201514676354-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Mar 30, 2010
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A nacelle for a turbofan propulsion system that extends along a centerline includes a forward cowling and an aft cowling. To improve the fit of a turbofan propulsion system in the space between the wing and ground of a fixed-wing aircraft, the aft cowling of the nacelle is modified. The aft cowling has a non-circular cross-sectional geometry disposed in a plane substantially perpendicular to the centerline. The non-circular cross-sectional geometry includes a radially recessed section disposed between first and second curved sections. The first and the second curved sections each have a radius that is greater than a radial distance between the centerline and a center point of the radially recessed section.

First claim

What is claimed is:

1. A nacelle for a turbofan propulsion system that extends along a centerline, comprising:
a forward cowling; and
an aft cowling having a non-circular cross-sectional geometry disposed in a plane substantially perpendicular to the centerline, which non-circular cross-sectional geometry includes a first radially recessed section disposed between first and second curved sections;
wherein the first and the second curved sections each have a radius that is greater than a radial distance between the centerline and a center point of the first radially recessed section;
wherein the first and the second curved sections each have a non-circular geometry;
wherein the first and the second curved sections each extend between first and second ends, the first and the second curved sections each are continuously curved between the first and the second ends, and the first radially recessed section extends between the first ends of the first and the second curved sections;
wherein the first radially recessed section is at a top end of the aft cowling, and the first radially recessed section has a compound cross-sectional geometry.

2. A nacelle for a turbofan propulsion system, comprising:
a forward cowling; and
an aft cowling axially extending from the forward cowling along a centerline, which aft cowling includes a bypass nozzle having a non-circular cross-sectional geometry disposed in a plane substantially perpendicular to the centerline, which non-circular cross-sectional geometry includes a first radially recessed section disposed between first and second curved sections;
wherein the first and the second curved sections each have a radius that is greater than a radial distance between the centerline and a center point of the first radially recessed section;
wherein the first and the second curved sections each have a non-circular geometry;
wherein the first and the second curved sections each extend between first and second ends, the first and the second curved sections each are continuously curved between the first and the second ends, and the first radially recessed section extends between the first ends of the first and second curved sections;
wherein the first radially recessed section is configured to be substantially circumferentially aligned with a pylon for mounting the turbofan propulsion system; and
wherein the first radially recessed section has a compound cross-sectional geometry.

3. The nacelle of claim 2 , wherein the aft cowling further includes an intermediate region having a substantially non-circular cross-sectional geometry disposed in a plane perpendicular to the centerline.

4. The nacelle of claim 2 , wherein the bypass nozzle is configured as a variable area fan nozzle that includes a plurality of nozzle panels that slide along a plurality of track fairings.

5. The nacelle of claim 4 , wherein
a first one of the track fairings is disposed on a top portion of the aft cowling, and is circumferentially aligned between the first and the second curved sections of the non-circular cross-sectional geometry; and
a second one of the track fairings is disposed on a bottom portion of the aft cowling, and is circumferentially aligned between the first and the second curved sections of the non-circular cross-sectional geometry.

6. A turbofan propulsion system, comprising:
an engine core having a centerline; and
a nacelle disposed around the engine core, which nacelle includes:
a forward cowling; and
an aft cowling having a non-circular cross-sectional geometry disposed in a plane substantially perpendicular to the centerline, which non-circular cross-sectional geometry includes a first radially recessed section disposed between first and second curved sections;
wherein the first and the second curved sections each have a radius that is greater than a radial distance between the centerline and a center point of the first radially recessed section;
wherein the first and the second curved sections each have a non-circular geometry;
wherein the first and the second curved sections each extend between first and second ends, wherein the first and the second curved sections each are continuously curved between the first and the second ends, wherein the first radially recessed section extends between the first ends of the first and the second curved sections;
wherein the first radially recessed section is at a top end of the aft cowling and has a compound cross-sectional geometry.

7. The propulsion system of claim 6 , wherein the aft cowling further includes an intermediate region having a substantially non-circular cross-sectional geometry disposed in a plane perpendicular to the centerline.

8. The propulsion system of claim 6 , wherein the aft cowling includes a variable area fan nozzle that includes a plurality of nozzle panels that slide along a plurality of track fairings.

9. The propulsion system of claim 8 , wherein
a first one of the track fairings is disposed on a top portion of the aft cowling, and is circumferentially aligned between the first and the second curved sections of the non-circular cross-sectional geometry; and
a second one of the track fairings is disposed on a bottom portion of the aft cowling, and is circumferentially aligned between the first and the second curved sections of the non-circular cross-sectional geometry.

10. A nacelle for an aircraft propulsion system, comprising:
a forward cowling extending along a centerline, the forward cowling having a cross-sectional geometry disposed in a first plane substantially perpendicular to the centerline; and
an aft cowling having a non-circular cross-sectional geometry disposed in a second plane substantially perpendicular to the centerline, wherein the non-circular cross-sectional geometry includes a radially recessed section disposed between a pair of opposing side curved sections;
wherein each of the side curved sections has a radius that is greater than a radial distance between the centerline and a center point of the radially recessed section;
wherein the radius of a first of the side curved sections is a variable radius;
wherein each of the side curved sections extends between a first end and a second end, each of the side curved sections is continuously curved between its respective first and second ends, and the radially recessed section extends between the first ends of the side curved sections;
wherein the radially recessed section has a cross-sectional geometry with a variable radius, and the radially recessed section is configured at a top end of the aft cowling; and
wherein the cross-sectional geometry of the forward cowling is different than the non-circular cross-sectional geometry of the aft cowling.

11. The nacelle of claim 10 , wherein the aft cowling further includes an intermediate region having a substantially non-circular cross-sectional geometry disposed in a plane perpendicular to the centerline.

12. A nacelle for an aircraft propulsion system, comprising:
a forward cowling extending along a centerline; and
an aft cowling having a non-circular cross-sectional geometry disposed in a plane substantially perpendicular to the centerline, wherein the non-circular cross-sectional geometry includes a radially recessed section disposed between a pair of opposing side curved sections;
wherein each of the side curved sections has a radius that is greater than a radial distance between the centerline and a center point of the radially recessed section;
wherein the radius of a first of the side curved sections is a variable radius;
wherein each of the side curved sections extends between a first end and a second end, each of the side curved

Assignees

• United Technologies Corp

Inventors

• Murphy Michael J
• Malecki Robert E

Classifications

• F02C3/10

  with another turbine driving an output shaft but not driving the compressor · CPC title

• B64D29/02 Primary

  associated with wings · CPC title

• F01D25/24 Primary

  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