# US 8,540,490 B2 · Noise reduction in a turbomachine, and a related method thereof

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- Number: US 8,540,490 B2
- Document ID: US8540490B2
- Status: Granted
- Kind: B2
- Application number: 13/247,096
- Filed: 2011-09-28
- Published: 2012-12-27
- Granted: 2013-09-24
- Earliest claimed: 2008-06-20
- Assignees: General Electric Company
- Applicants: Kishore Ramakrishnan; Trevor Howard Wood
- Inventors: Kishore Ramakrishnan; Trevor Howard Wood
- Web page: https://patentgrep.com/patent/US8540490B2

## CPC

- F01D 5/146: {of blades with tandem configuration, split blades or slotted blades}
- F01D 5/26: Antivibration means not restricted to blade form or construction or to blade-to-blade connections {or to the use of particular materials}
- F01D 25/04: Antivibration arrangements
- F04D 29/321: {for axial flow compressors}
- F04D 29/544: {Blade shapes}
- F04D 29/666: {by means of rotor construction or layout, e.g. unequal distribution of blades or vanes}
- F05D 2260/96: Preventing, counteracting or reducing vibration or noise
- 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 apparatus includes a first set of blades and a second set of blades disposed downstream relative to the first set of blades. The first set of blades includes a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters. The second set of blades includes a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters.

## Claims

### Claim 1

An apparatus, comprising:
a first set of blades comprising:
a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters; and
a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters; wherein the first subset of blades and the second subset of blades are arranged so that a first wake generated by the first subset of blades is distinct from a second wake generated by the second subset of blades; and
a second set of blades disposed downstream relative to the first set of blades; wherein at least one set of blades among the first set of blades and the second set blades are movable relative to each other.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the second subset of blades are disposed offset along a circumferential direction and an axial direction relative to the first subset of blades.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the first set of blades comprises a plurality of rotatable blades and the second set of blades comprises a plurality of stationary blades.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the first set of blades comprises a plurality of stationary blades and the second set of blades comprises a plurality of rotatable blades.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the first set of blades are counter rotatable relative to the second set of blades.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the one or more first geometric parameters comprise at least one of a camber, a stagger, a chord, a blade thickness, a trailing edge camber angle, blade sweep, and a blade dihedral.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the one or more second geometric parameters comprises at least one of a camber, a stagger, a chord, a blade thickness, a trailing edge camber angle, blade sweep, and a blade dihedral.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the apparatus comprises a turbomachine.

### Claim 9

An apparatus, comprising:
a first set of rotatable blades comprising:
a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters; and
a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters; wherein the first subset of blades and the second subset of blades are arranged so that a first wake generated by the first subset of blades is distinct from a second wake generated by the second subset of blades; and
a second set of stationary blades disposed downstream relative to the first set of blades.

### Claim 10

An apparatus, comprising:
a first set of stationary blades comprising:
a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters; and
a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters; and
a second set of rotatable blades disposed downstream relative to the first set of blades.

### Claim 11

An apparatus, comprising:
a first set of blades comprising:
a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters; and
a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters; and
a second set of stationary blades disposed downstream relative to the first set of blades; wherein the first set of blades are counter rotatable relative to the second set of blades.

### Claim 12

An apparatus, comprising:
a first set of blades comprising:
a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters; and
a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters; and
a second set of blades disposed downstream relative to the first set of blades; wherein at least one set of blades among the first set of blades and the second set blades are movable relative to each other, wherein the first set of blades comprises a plurality of stationary blades and the second set of blades comprises a plurality of rotatable blades.

### Claim 13

An apparatus, comprising:
a first set of blades comprising:
a first subset of blades, wherein each blade among the first subset of blades comprises one or more first geometric parameters; and
a second subset of blades, wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters; and
a second set of blades disposed downstream relative to the first set of blades; wherein at least one set of blades among the first set of blades and the second set blades are movable relative to each other, wherein the first set of blades are counter rotatable relative to the second set of blades.

### Claim 14

A method, comprising:
rotating a first set of blades relative to a second set of blades disposed downstream relative to the first set of blades, wherein the first set of blades comprises a first subset of blades and a second subset of blades; wherein each blade among the first subset of blades comprises one or more first geometric parameters; wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters;
impacting a first wake generated by the first subset of blades with the second set of blades; and
impacting a second wake generated by the second subset of blades with the second set of blades such that spectral content of wake excitation perceived, and an acoustic signal generated by the second set of blades is altered, wherein the first wake is distinct from the second wake.

### Claim 15 (depends on 14)

The method of claim 14, wherein the one or more first geometric parameters comprise at least one of a camber, a stagger, a chord, a blade thickness, a trailing edge camber angle, blade sweep, and a blade dihedral.

### Claim 16 (depends on 14)

The method of claim 14, wherein the one or more second geometric parameters comprises at least one of a camber, a stagger, a chord, a blade thickness, and a trailing edge camber angle, blade sweep, and a blade dihedral.

### Claim 17 (depends on 14)

The method of claim 14, further comprising counter rotating the second set of blades relative to the first set of blades.

### Claim 18

A method, comprising:
rotating one set of blades relative to another set of blades disposed upstream relative to the one set of blades, wherein the other set of blades comprises a first subset of blades and a second subset of blades; wherein each blade among the first subset of blades comprises one or more first geometric parameters; wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters;
impacting a first wake generated by the first subset of blades with the one set of blades; and
impacting a second wake generated by the second subset of blades with the one set of blades such that spectral content of wake excitation perceived, and an acoustic signal generated by the one set of blades is altered, wherein the first wake is distinct from the second wake.

### Claim 19 (depends on 18)

The method of claim 18, wherein the one or more first geometric parameters comprises at least one of a camber, a stagger, a chord, a blade thickness, a trailing edge camber angle, blade sweep, and a blade dihedral of each blade among the first subset of blades.

### Claim 20 (depends on 18)

The method of claim 18, wherein the one or more second geometric parameters comprises at least one of a camber, a stagger, a chord, a blade thickness, a trailing edge camber angle, blade sweep, and a blade dihedral of each blade among the second subset of blades.

### Claim 21

A method, comprising:
moving at least one set of blades among a first set of blades and a second set of blades relative to each other; wherein the second set of blades are disposed downstream relative to the first set of blades, wherein the first set of blades comprises a first subset of blades and a second subset of blades; wherein each blade among the first subset of blades comprises one or more first geometric parameters; wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters;
impacting a first wake generated by the first subset of blades with the second set of blades; and
impacting a second wake generated by the second subset of blades with the second set of blades such that spectral content of wake excitation perceived, and an acoustic signal generated by the second set of blades is altered, wherein the first wake is distinct from the second wake.

### Claim 22

A method, comprising:
rotating a first set of blades relative to a second set of blades disposed downstream relative to the first set of blades, wherein the first set of blades comprises a first subset of blades and a second subset of blades; wherein each blade among the first subset of blades comprises one or more first geometric parameters; wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters;
counter rotating the second set of blades relative to the first set of blades;
impacting a first wake generated by the first subset of blades with the second set of blades; and
impacting a second wake generated by the second subset of blades with the second set of blades such that spectral content of wake excitation perceived, and an acoustic signal generated by the second set of blades is altered.

### Claim 23

A method, comprising:
rotating a first set of blades relative to a second set of blades disposed downstream relative to the first set of blades, wherein the first set of blades comprises a first subset of blades and a second subset of blades; wherein each blade among the first subset of blades comprises one or more first geometric parameters; wherein each blade among the second subset of blades comprises one or more second geometric parameters different from the one or more first geometric parameters;
impacting a first wake generated by the first subset of blades with the second set of blades;
impacting a second wake generated by the second subset of blades with the second set of blades such that spectral content of wake excitation perceived, and an acoustic signal generated by the second set of blades is altered; and
counter rotating the second set of blades relative to the first set of blades.