# US 10,479,517 B2 · Composite fan cowl with a core having tailored thickness

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- Number: US 10,479,517 B2
- Document ID: US10479517B2
- Status: Granted
- Kind: B2
- Application number: 15/369,195
- Filed: 2016-12-05
- Published: 2018-06-07
- Granted: 2019-11-19
- Earliest claimed: 2016-12-05
- Assignees: The Boeing Company
- Applicants: The Boeing Company
- Inventors: Joseph Benjamin LaBelle; Jason Franklin Joel
- Web page: https://patentgrep.com/patent/US10479517B2

## CPC

- B64D 29/08: Inspection panels for power plants
- F01D 25/28: Supporting or mounting arrangements, e.g. for turbine casing
- B64C 2001/0072: {from composite materials}
- B64D 29/06: Attaching of nacelles, fairings or cowlings
- F05D 2240/14: Casings or housings protecting or supporting assemblies within
- Y02T 50/40: Weight reduction
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- B64C: AEROPLANES; HELICOPTERS
- 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

An engine nacelle comprised of a top portion with hinges and a composite fan cowl pivotally connected to the top portion by the hinges. The composite fan cowl comprises a core with a hinge zone having a first thickness and a body zone having a second thickness. The hinge zone includes the hinges. The body zone is distal from the hinge zone, and the first thickness is less than the second thickness.

## Claims

### Claim 1

A composite fan cowl connected to hold open rods, the composite fan cowl comprising:
laminate skins; and
a core, comprising:
a hinge zone having a first thickness;
a body zone having a second thickness different than the first thickness, the body zone different than the hinge zone; and
areas of increased thickness having a third thickness, the third thickness greater than the second thickness, the areas of increased thickness disposed in the body zone of the core, and the areas of increased thickness associated with hold open rods.

### Claim 2 (depends on 1)

The composite fan cowl of claim 1, wherein the areas of increased thickness each comprise a ramp up, a pad, and a ramp down in a direction of an arc of the core.

### Claim 3 (depends on 2)

The composite fan cowl of claim 2, wherein the core is symmetric about a centerline running in the direction of the arc of the core.

### Claim 4 (depends on 2)

The composite fan cowl of claim 2, wherein a thickness of the pad is in a range of 1.5 inches to 2.5 inches.

### Claim 5 (depends on 1)

The composite fan cowl of claim 1, wherein each respective thickness of the hinge zone and the body zone is in a range of 0.5 inches to 1 inch.

### Claim 6 (depends on 1)

The composite fan cowl of claim 1, wherein the first thickness is less than the second thickness.

### Claim 7 (depends on 6)

The composite fan cowl of claim 6, wherein the core has an arcuate length defined from the hinge zone to the body zone, with each of the hinge zone and the body zone having a respective arcuate length, and wherein a ratio of the arcuate length of the hinge zone to that of the body zone is less than about 1:4.

### Claim 8 (depends on 1)

The composite fan cowl of claim 1, wherein a thickness of each of the laminate skins is independent of thicknesses of the core.

### Claim 9 (depends on 1)

The composite fan cowl of claim 1, wherein a thickness of the areas of increased thickness is selected based on a bending moment of the composite fan cowl when subjected to wind gusts when the composite fan cowl is in an open position.

### Claim 10

A composite fan cowl comprising:
a hinge zone;
a body zone; and
a core, wherein:
a first portion of the core is disposed within the hinge zone;
a second portion of the core is disposed within the body zone;
the first portion of the core has a first thickness;
the second portion of the core has a second thickness;
the core has two areas of increased thickness, each having a third thickness;
the two areas of increased thickness are positioned within the second portion of the core;
the first thickness is different than the second thickness; and
the third thickness is greater than the second thickness.

### Claim 11 (depends on 10)

The composite fan cowl of claim 10, wherein the two areas of increased thickness of the core comprise a plurality of ramps.

### Claim 12 (depends on 11)

The composite fan cowl of claim 11, wherein the plurality of ramps comprise a ramp up for each of the two areas of increased thickness and a ramp down for each of the two areas of increased thickness, wherein the ramp up for each of the two areas of increased thickness progressively increases thickness from the second thickness to the third thickness, and wherein the ramp down for each of the two areas of increased thickness progressively decreases thickness from the third thickness to the second thickness.

### Claim 13 (depends on 12)

The composite fan cowl of claim 12, wherein the ramp up for each of the two areas of increased thickness and the ramp down for each of the two areas of increased thickness have a change in thickness along an arc of the core, and wherein the ramp up for each of the two areas of increased thickness and the ramp down for each of the two areas of increased thickness are each in a range of about 10 degrees to about 25 degrees.

### Claim 14 (depends on 10)

The composite fan cowl of claim 10, wherein the second thickness is greater than the first thickness, and wherein the hinge zone is above the body zone along an arc of the core.

### Claim 15 (depends on 10)

The composite fan cowl of claim 10, wherein:
the first thickness and the second thickness are in a first range of 0.5 inches to 1.5 inches; and
the third thickness is in a second range of 1.5 inches to 2.5 inches.

### Claim 16 (depends on 10)

The composite fan cowl of claim 10, wherein the two areas of increased thickness provide local stiffening in an area of highest strain under gust loading.

### Claim 17 (depends on 10)

The composite fan cowl of claim 10, wherein the two areas of increased thickness provide local stiffening in an area of highest bending moment on the composite fan cowl.

### Claim 18

An engine nacelle comprising:
a top portion with hinges; and
a composite fan cowl pivotally connected to the top portion by the hinges, the composite fan cowl comprising a core, wherein the core includes:
a hinge zone having a first thickness of the core; and
a body zone having a second thickness of the core, the hinge zone including the hinges, the body zone distally disposed from the hinge zone, and wherein the first thickness of the core less than the second thickness of the core.

### Claim 19 (depends on 18)

The engine nacelle of claim 18, wherein the first thickness of the core is at least 10% less than the second thickness of the core, wherein two areas having a third thickness of the core are positioned within the body zone, and wherein the third thickness of the core is greater than the second thickness of the core.

### Claim 20

A composite fan cowl comprising:
a core with a hinge zone having a first thickness, a body zone having a second thickness, and two areas of increased thickness including a third thickness;
wherein:
the two areas of increased thickness of the core comprise a plurality of ramps;
the two areas of increased thickness are positioned within the body zone;
the first thickness and second thickness are different from each other;
the two areas of increased thickness have a greater thickness than the second thickness;
the first thickness and the second thickness are in a range of 0.5 inches and 1.5 inches; and
the plurality of ramps comprise a ramp up for each of the two areas of increased thickness and a ramp down for each of the two areas of increased thickness, the ramp up for each of the two areas of increased thickness having progressively increased thickness from the second thickness to the third thickness, and the ramp down for each of the two areas of increased thickness having progressively decreased thickness from the third thickness to the second thickness.

### Claim 21 (depends on 20)

The composite fan cowl of claim 20, wherein the plurality of ramps:
have a change in thickness along an arc of the core; and
are each in a range of about 10 degrees to about 25 degrees.