# US 12,215,597 B1 · Gas turbine engine rotor blade geometry and method for selecting same

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- Number: US 12,215,597 B1
- Document ID: US12215597B1
- Status: Granted
- Kind: B1
- Application number: 18/424,383
- Filed: 2024-01-26
- Granted: 2025-02-04
- Earliest claimed: 2024-01-26
- Assignees: Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Anthony Bruni; Jason Nichols; Ramy Rashad; Mohammadreza Amiralaei
- Web page: https://patentgrep.com/patent/US12215597B1

## CPC

- F01D 5/141: {Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147)}
- F04D 29/284: {for compressors}
- F04D 29/324: {Blades}
- F05D 2220/323: for aircraft propulsion, e.g. jet engines
- F05D 2240/305: related to the pressure side of a rotor blade
- F05D 2250/294: grooved
- F05D 2250/38: angled, e.g. sweep angle
- F05D 2250/712: concave
- F05D 2250/713: inflexed
- F05D 2260/941: particularly aimed at mechanical or thermal stress reduction
- 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)
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)
- 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 aircraft propulsion system includes a bladed rotor configured for rotation about a rotational axis. A rotor blade of the bladed rotor of rotor blades includes a blade body. The blade body has a blade span extending between and to a base end and a tip end. The blade body has a blade chord extending between and to a leading edge and a trailing edge. The blade body forms a pressure side surface and a suction side surface. The blade body forms a recess at the pressure side surface. The recess includes a recess surface portion forming a portion of the pressure side surface. The recess surface portion has a recess height. The recess height is greater than or equal to a Y-value of 0.025 for a normalized two-dimensional curve of a surface profile of the recess surface portion taken along a Y-Z plane orthogonal to the rotational axis for a recess span.

## Claims

### Claim 1

An aircraft propulsion system comprising:
a bladed rotor configured for rotation about a rotational axis, the bladed rotor includes a plurality of rotor blades, and each rotor blade of the plurality of rotor blades includes a blade body,
the blade body extends between and to a base end and a tip end, the blade body has a blade span extending between and to the base end and the tip end, the blade body extends between and to a leading edge and a trailing edge, the blade body has a blade chord extending between and to the leading edge and the trailing edge, the blade body forms a pressure side surface and a suction side surface, each of the pressure side surface and the suction side surface extend between and to the base end and the tip end and between and to the leading edge and the trailing edge, the blade body forms a recess at the pressure side surface, the recess includes a recess surface portion forming a portion of the pressure side surface, and the recess surface portion has a recess height, and
the recess height is greater than or equal to a Y-value of 0.025 for a normalized two-dimensional curve of a surface profile of the recess surface portion taken along a Y-Z plane orthogonal to the rotational axis for a recess span, a Z-direction of the Y-Z plane extends in a span direction of the blade span, a Y-direction of the Y-Z plane extends orthogonal to the Z-direction, the recess span extends between and to a minimum span position and a maximum span position in the Z-direction, and the recess height is a maximum height measured in the Y-direction between the two-dimensional curve and a straight line intersecting the two-dimensional curve at the minimum span position and the maximum span position.

### Claim 2 (depends on 1)

The aircraft propulsion system of claim 1, wherein the recess height is less than or equal to the Y-value of 0.1.

### Claim 3 (depends on 2)

The aircraft propulsion system of claim 2, wherein the recess height is greater than or equal to the Y-value of 0.04.

### Claim 4 (depends on 1)

The aircraft propulsion system of claim 1, wherein the minimum span position is equal to 15 percent of the blade span and the maximum span position is equal to 90 percent of the blade span.

### Claim 5 (depends on 1)

The aircraft propulsion system of claim 1, wherein the minimum span position is equal to 40 percent of the blade span and the maximum span position is equal to 90 percent of the blade span.

### Claim 6 (depends on 1)

The aircraft propulsion system of claim 1, wherein the recess extends axially along an axial chord of the blade chord between and to a minimum axial chord position and a maximum axial chord position, the minimum axial chord position is greater than or equal to 50 percent of the axial chord and the maximum axial chord position is less than or equal to 80 percent of the axial chord.

### Claim 7 (depends on 6)

The aircraft propulsion system of claim 6, wherein the recess height is greater than or equal to the Y-value of 0.025 between and to the minimum axial chord position and the maximum axial chord position.

### Claim 8 (depends on 1)

The aircraft propulsion system of claim 1, wherein the recess surface portion has a first recess shape which deviates from a second pressure side shape of surrounding portions of the pressure side surface.

### Claim 9 (depends on 1)

The aircraft propulsion system of claim 1, wherein the blade body forms a bulge at the suction side surface coincident with the recess along the blade chord, the bulge includes a bulge surface portion forming a portion of the suction side surface, and the bulge surface portion has a first bulge shape which deviates from a second suction side shape of surrounding portions of the suction side surface.

### Claim 10 (depends on 1)

The aircraft propulsion system of claim 1, further comprising a compressor section, and the compressor section includes the bladed rotor.

### Claim 11

A rotor blade for a bladed compressor rotor of an aircraft propulsion system, the rotor blade comprising:
a blade body extending between and to a base end and a tip end, the blade body has a blade span extending between and to the base end and the tip end, the blade body extends between and to a leading edge and a trailing edge, the blade body has a blade chord extending between and to the leading edge and the trailing edge, the blade body forms a pressure side surface and a suction side surface, each of the pressure side surface and the suction side surface extend between and to the base end and the tip end and between and to the leading edge and the trailing edge, the blade body forms a recess at the pressure side surface, and the recess includes a recess surface portion forming a portion of the pressure side surface,
the recess is disposed within a recess span extending in a span direction of the blade span, the recess span extends between and to a minimum span position and a maximum span position, the minimum span position is less than or equal to 40 percent of the blade span, and the maximum span position is equal to 90 percent of the blade span, and
the recess is disposed within a recess chord extending in a chord direction of the blade chord, the recess chord extends between and to a minimum chord position and a maximum chord position, and the recess chord is a portion of the blade chord, and
the recess surface portion has a first recess shape which deviates from a second pressure side shape of surrounding portions of the pressure side surface.

### Claim 12 (depends on 11)

The rotor blade of claim 11, wherein the blade body forms a bulge at the suction side surface coincident with the recess along the blade chord, and the bulge includes a bulge surface portion forming a portion of the suction side surface.

### Claim 13 (depends on 12)

The rotor blade of claim 12, wherein the bulge surface portion has a first bulge shape which deviates from a second suction side shape of surrounding portions of the suction side surface.

### Claim 14 (depends on 11)

The rotor blade of claim 11, wherein the minimum span position is equal to 40 percent of the blade span.