Engine casing of an aircraft gas turbine having sound-absorbing elements in the fan inflow region

Patent metadata

Field	Value
Publication number	US-9371778-B2
Application number	US-201313743017-A
Country	US
Kind code	B2
Filing date	Jan 16, 2013
Priority date	Jan 26, 2012
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

The present invention relates to an engine casing of an aircraft gas turbine having a radially inner honeycomb-structured layer arranged on the engine casing in the flow direction upstream of a fan in the area of an inflow-side air inlet, characterized in that sound-absorbing elements are arranged radially outside at least one axial section of the honeycomb-structured layer, said elements extending in the axial direction and being arranged annularly next to one another in the circumferential direction.

First claim

What is claimed is:

1. An engine casing assembly of an aircraft gas turbine comprising:
a fan casing;
a radially inner honeycomb-structured layer arranged on the fan casing in a flow direction upstream of a fan in an area of an inflow-side air inlet, the honeycomb-structured layer including a plurality of chambers;
sound-absorbing elements arranged radially outside at least one axial section of the honeycomb-structured layer, the elements extending in an axial direction and being arranged annularly next to one another in a circumferential direction;
an intermediate chamber having a first end and a second end, the intermediate chamber extending substantially in the axial direction between the first end and the second end and having a first length extending between the first end and the second end;
each sound-absorbing element including:
a hollow chamber having a third end and a fourth end, the hollow chamber extending substantially in the axial direction between the third end and the fourth end and having a second length extending between the third end and the fourth end;
a wall separating the hollow chamber and the intermediate chamber;
an interconnecting passage connecting the fourth end to the second end to increase a tuned length of the sound-absorbing element to a length including both the first length and the second length;
recesses connecting the chambers of the honeycomb-structured layer to the hollow chamber;
wherein the chambers of the honeycomb-structured layer connect to the intermediate chamber only via the hollow chamber and the interconnecting passage.

2. The engine casing assembly in accordance with claim 1 , wherein the sound-absorbing elements are arranged in the fan casing with the fan casing radially outwardly surrounding the sound-absorbing elements.

3. The engine casing assembly in accordance with claim 1 , wherein the sound-absorbing elements are radially remote from at least one chosen from the fan casing and the honeycomb-structured layer.

4. The engine casing assembly in accordance with claim 1 , wherein at least one of the sound-absorbing elements in the circumferential direction includes at least one sealing rib contacting the fan casing.

5. The engine casing assembly in accordance with claim 4 , wherein the sound-absorbing elements are radially remote from at least one chosen from the fan casing and the honeycomb-structured layer.

6. The engine casing assembly in accordance with claim 2 , wherein the sound-absorbing elements are radially remote from at least one chosen from the fan casing and the honeycomb-structured layer.

7. The engine casing assembly in accordance with claim 6 , wherein at least one of the sound-absorbing elements in the circumferential direction includes at least one sealing rib contacting the fan casing.

8. The engine casing assembly in accordance with claim 2 , wherein at least one of the sound-absorbing elements in the circumferential direction includes at least one sealing rib contacting the fan casing.

Assignees

• Rolls Royce Deutschland

Inventors

• Todorovic Predrag
• Kubisch Thomas

Classifications

• F02K1/827 Primary

  Sound absorbing structures or liners · CPC title

• F02C7/045

  having provisions for noise suppression · CPC title

• F02C7/24 Primary

  Heat or noise insulation (air intakes having provisions for noise suppression F02C7/045; turbine exhaust heads, chambers, or the like F01D25/30; silencing nozzles of jet-propulsion plants F02K1/00) · CPC title

• F02K3/06

  with front fan · CPC title

• B64D2033/0206

  comprising noise reduction means, e.g. acoustic liners · CPC title