Convergent-divergent nozzle for a turbofan engine of a supersonic aircraft and method for adjusting the nozzle throat surface in a nozzle of a turbofan engine

Patent metadata

Field	Value
Publication number	US-10738735-B2
Application number	US-201815901365-A
Country	US
Kind code	B2
Filing date	Feb 21, 2018
Priority date	Feb 27, 2017
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A convergent-divergent nozzle for a turbofan engine of a supersonic aircraft, wherein the nozzle has an inner wall and forms a flow channel with a nozzle throat surface and a nozzle exit surface. A trim ring that is displaceable in the axial direction between a first position and a second position is provided, wherein the inner wall of the nozzle and the trim ring are embodied and positioned with respect to each other in such a manner that the trim ring extends at a radial distance to the inner wall in the first position, wherein a ring-shaped bypass channel is provided, extending between the trim ring and the inner wall of the nozzle, and the trim ring abuts the inner wall in the second position.

First claim

What is claimed is:

1. A convergent-divergent nozzle for a turbofan engine of a supersonic aircraft, wherein the nozzle comprises:
an inner wall,
the inner wall forming a flow channel with a nozzle throat surface and a nozzle exit surface,
the inner wall radially delimiting an exterior of the flow channel through the nozzle,
a trim ring that is displaceable in an axial direction between a first position and a second position, wherein the inner wall of the nozzle and the trim ring are configured and positioned with respect to each other in such a manner that;
the trim ring extends at a radially inward distance to the inner wall in the first position forming an annular bypass channel extending between the trim ring and the inner wall of the nozzle, the bypass channel providing an additional cross-sectional surface of the flow channel,
the trim ring abuts the inner wall in the second position,
the bypass channel is closed in the second position,
in the first position, the nozzle throat surface is formed by a sum of a smallest cross-sectional surface of the trim ring and a smallest cross-sectional surface of the bypass channel, and
in the second position, the nozzle throat surface is formed by a narrowest cross-sectional surface of the trim ring.

2. The nozzle according to claim 1 , wherein the first position is an upstream position and the second position is a downstream position, wherein in the upstream position the bypass channel is formed between the trim ring and the inner wall of the nozzle, and in the downstream position the trim ring abuts the inner wall.

3. The nozzle according to claim 1 , wherein the inner wall of the nozzle and the trim ring are configured and positioned with respect to each other in such a manner that a minimal cross-sectional surface of the bypass channel and thus the nozzle throat surface of the flow channel is successively reduced as the trim ring is displaced from the first position into the second position.

4. The nozzle according to claim 1 , wherein the trim ring has an upstream area that converges in a flow direction and connected downstream to the upstream area is at least one chosen from a cylindrical area or an area that diverges in the flow direction.

5. The nozzle according to claim 4 , wherein the trim ring includes the cylindrical area adjoining the upstream area, and the area that diverges in the flow direction.

6. The nozzle according to claim 1 , wherein the inner wall of the nozzle forms a convergent area in which the additional cross-sectional surface of the inner wall converges in a flow direction.

7. The nozzle according to claim 6 , wherein the inner wall of the nozzle forms at least one chosen from a cylindrical area or a divergent area downstream of the convergent area.

8. The nozzle according to claim 6 , wherein the trim ring includes an upstream area that converges in the flow direction and connected downstream of the upstream area is at least one chosen from a cylindrical area or an area that diverges in the flow direction, and wherein the upstream area of the trim ring and the convergent area of the inner wall extend at least partially across a same axial area of the nozzle when the trim ring is in the first position.

9. The nozzle according to claim 8 , wherein the upstream area of the trim ring and the convergent area of the inner wall extend substantially in parallel to each other when the trim ring is in the first position.

10. The nozzle according to claim 1 , wherein the trim ring includes an upstream area that converges in a flow direction and connected downstream of the upstream area is at least one chosen from a cylindrical area or an area that diverges in the flow direction, and wherein an upstream edge of the upstream area of the trim ring abuts the inner wall of the nozzle in the second position.

11. The nozzle according to claim 10 , wherein the inner wall of the nozzle forms a convergent area in which the additional cross-sectional surface of the inner wall converges in the flow direction, and wherein the upstream edge abuts the inner wall of the nozzle in the convergent area of the inner wall or at a transition of the convergent area to a cylindrical or divergent area connecting thereto downstream.

12. The nozzle according to claim 1 , wherein in the second position, the trim ring abuts at the inner wall along a circumferential line.

13. The nozzle according to claim 1 , wherein the inner wall of the nozzle is non-adjustable.

14. The nozzle according to claim 1 , wherein the nozzle is a three-dimensional nozzle.

15. The nozzle according to claim 1 , wherein, at a downstream end of the nozzle, the nozzle includes a nozzle exit ring that is displaceable in the axial direction between a first, upstream position and a second, downstream position, wherein
the nozzle, in the second position of the nozzle exit ring, forms an annular additional flow channel that extends from an outer skin of the nozzle to the flow channel, and via which ambient air can flow into the flow channel,
the annular additional flow channel is closed in the first position of the nozzle exit ring, and
the annular additional flow channel is configured such that air that is discharged from the additional flow channel forms a radially outer boundary flow in the flow channel.

16. A convergent-divergent nozzle for a turbofan engine of a supersonic aircraft, comprising:
an inner wall forming and delimiting an exterior of a flow channel through the nozzle, wherein the flow channel includes a nozzle throat surface and a nozzle exit surface,
a trim ring that is displaceable in an axial direction between a first position and a second position, wherein
the inner wall of the nozzle and the trim ring are configured and positioned with respect to each other in such a manner that;
the trim ring extends at a radially inward distance to the inner wall in the first position forming an annular bypass channel extending between the trim ring and the inner wall of the nozzle,
the trim ring abuts the inner wall in the second position,
the bypass channel is closed in the second position;

the trim ring includes an upstream area that converges in a flow direction and connected downstream of the upstream area is at least one chosen from a cylindrical area or an area that diverges in the flow direction,
the inner wall of the nozzle forms a convergent area in which a cross-sectional surface of the inner wall converges in the flow direction, and
an upstream edge of the upstream area of the trim ring abuts the inner wall of the nozzle in the second position.

17. A method for adjusting a nozzle throat surface in a nozzle of a turbofan engine, comprising:
providing a nozzle that comprises:
an inner wall,
the inner wall forming a flow channel with a nozzle throat surface and a nozzle exit surface,
the inner wall radially delimiting an exterior of the flow channel through the nozzle,
a trim ring that is displaceable in an axial direction between a first position and a second position, wherein the inner wall of the nozzle and the trim ring are embodied and positioned with respect to each other in such a manner that;
the trim ring extends at a radially inward distance to the inner wall in the first position, forming an annular bypass channel extending between the trim ring and the inner wall of the nozzle, the bypass channel providing an additional cross-sectional surface of the flow channel,
the trim ring abuts the inner wall in the second position,
the bypass channel is closed in the second position, and
in the second position, the nozzle throat

Assignees

• Rolls Royce Deutschland Ltd & Co Kg

Inventors

• Todorovic Predrag

Classifications

• F05D2220/80

  in supersonic vehicles excluding hypersonic vehicles or ram, scram or rocket propulsion · CPC title

• F02K3/06

  with front fan · CPC title

• B64D33/04

  of exhaust outlets or jet pipes · CPC title

• F02K1/08 Primary

  by axially moving or transversely deforming an internal member, e.g. the exhaust cone · CPC title

• B64C30/00

  Supersonic type aircraft · CPC title