# US 2013/0156542 A1 · Energy-absorbing fan case for a gas turbine engine

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- Number: US 2013/0156542 A1
- Document ID: US20130156542A1
- Status: Published application
- Kind: A1
- Application number: 13/327,730
- Filed: 2011-12-15
- Published: 2013-06-20
- Earliest claimed: 2011-12-15
- Assignees: United Technologies Corporation
- Inventors: Gabriel L. Suciu; Allan R. Penda; Christopher M. Dye; Jason Elliott
- Web page: https://patentgrep.com/patent/US20130156542A1

## CPC

- F01D 21/045: {special arrangements in stators or in rotors dealing with breaking-off of part of rotor}
- F02K 1/70: using thrust reverser flaps or doors mounted on the fan housing
- F05D 2250/25: helical
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A fan case of a gas turbine engine includes a fan blade containment section defined about an engine axis and a plurality of helical ribs adjacent to the fan blade containment section.

## Claims

### Claim 1

A fan case of a gas turbine engine comprising:
a fan blade containment section defined about an engine axis; and
a plurality of helical ribs adjacent to said fan blade containment section.

### Claim 2 (depends on 1)

The fan case as recited in claim 1, wherein said plurality of helical ribs are within a thrust reverser section.

### Claim 3 (depends on 1)

The fan case as recited in claim 1, wherein said plurality of helical ribs support a multiple of cascade airfoils.

### Claim 4 (depends on 1)

The fan case as recited in claim 1, further comprising a Fan Exit Guide Vane section downstream of said plurality of helical ribs.

### Claim 5 (depends on 1)

The fan case as recited in claim 1, further comprising a fan nacelle mounted to said fan case, said fan nacelle at least partially defined by a multiple of outer thrust reverser doors.

### Claim 6

A gas turbine engine comprising:
a fan case defined about an engine axis;
a core case defined about said engine axis;
a multiple of Fan Exit Guide Vanes attached to said fan case and said core case;
a fan blade containment section within said fan case; and
a plurality of helical ribs within said fan case, said plurality of helical ribs downstream of said fan blade containment section.

### Claim 7 (depends on 6)

The gas turbine engine as recited in claim 6, wherein said plurality of helical ribs are within a thrust reverser section.

### Claim 8 (depends on 6)

The gas turbine engine as recited in claim 6, wherein said plurality of helical ribs support a multiple of cascade airfoils.

### Claim 9 (depends on 6)

The gas turbine engine as recited in claim 6, further comprising a fan nacelle mounted to said fan case.

### Claim 10 (depends on 6)

The gas turbine engine as recited in claim 6, further comprising a fan mounted within said fan case, said fan axially in line with said fan blade containment section.

### Claim 11 (depends on 10)

The gas turbine engine as recited in claim 10, wherein said fan is driven through a geared architecture.

### Claim 12

A method of absorbing energy in a fan case of gas turbine engine during a fan blade impact event comprising:
axially deflecting the fan case in response to the fan blade impact event.

### Claim 13 (depends on 12)

The method as recited in claim 12, further comprising axially contracting the fan case through a plurality of helical ribs.

### Claim 14 (depends on 13)

The method as recited in claim 13, further comprising orienting the plurality of helical ribs in a direction of rotation of a fan.

### Claim 15 (depends on 14)

The method as recited in claim 14, further comprising driving the fan through a geared architecture.

### Claim 16 (depends on 13)

The method as recited in claim 13, further comprising directing thrust reverse flow through said plurality of helical ribs.

### Claim 17 (depends on 12)

The method as recited in claim 12, further comprising axially expanding the fan case through a plurality of helical ribs.

### Claim 18 (depends on 17)

The method as recited in claim 17, further comprising orienting the plurality of helical ribs in a direction opposite a direction of rotation of a fan.

### Claim 19 (depends on 18)

The method as recited in claim 18, further comprising driving the fan through a geared architecture.