Method for monitoring a turbomachine, device, system, aircraft and computer program product

Patent metadata

Field	Value
Publication number	US-12055459-B2
Application number	US-202017782451-A
Country	US
Kind code	B2
Filing date	Dec 4, 2020
Priority date	Dec 4, 2019
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

Method for monitoring a turbomachine comprising a stator and a rotor, device, system, aircraft and computer program product. The method comprises a step of acquiring an input signal which represents a deformation of the stator or rotor of the turbomachine. The input signal has been acquired by a deformation gauge which is attached to the stator or rotor. The input signal comprises a first component which represents deformations of the stator or rotor which are caused by rotation of the rotor vanes in relation to the stator, and a second component which represents deformations which are caused by different elements of the rotor vanes. The method comprises a step of re-sampling the input signal in order to obtain a re-sampled input signal comprising a predefined whole number of samples per revolution of the turbomachine rotor. The method also comprises a step of processing the re-sampled input signal, comprising: filtering the re-sampled input signal, making it possible to acquire a filtered input signal in which the second component is attenuated, and separating the filtered input signal into a plurality of third components, each third component representing a contribution to the deformation caused by a respective associated vane. The method also comprises a step of detecting, in a third component, contact between the vane associated with the third component and the stator.

First claim

The invention claimed is:

1. A method of monitoring a turbomachine comprising a stator and a rotor and a deformation gauge attached to the stator or to the rotor, the method comprising:
a step of acquiring an input signal by the deformation gauge, wherein the input signal comprises a first component representative of deformations of the stator or of the rotor caused by the rotation of the blades of the rotor with respect to the stator, and a second component representative of deformations of the stator or of the rotor caused by elements separate from the blades of the rotor;
a step of re-sampling the input signal to obtain a re-sampled input signal comprising a predefined integer number of samples per revolution of the rotor of the turbomachine;
a step of processing the re-sampled input signal, which comprises a filtering the re-sampled input signal to obtain a filtered input signal wherein the second component is attenuated and separating the filtered input signal into a plurality of third components, each third component being representative of a contribution to the deformation caused by a respective associated blade; and
a step of detecting, in a third component, a rub between the blade associated with the third component and the stator.

2. The method as claimed in claim 1 , wherein filtering the re-sampled input signal comprises determining values of a plurality of parameters of a model representative of the re-sampled input signal and determining a modeled input signal using the model representative of the re-sampled input signal and the determined values of the plurality of parameters.

3. The method as claimed in claim 2 , wherein the determined values of the plurality of parameters are those minimizing a deviation between the re-sampled input signal and an input signal modeled using the model representative of the re-sampled input signal and said determined values.

4. The method as claimed in claim 2 , wherein determining the values of the plurality of parameters of the model representative of the re-sampled input signal uses the following equation:
{circumflex over (b)} =(Φ T Φ −1 Φ T x

wherein:
{circumflex over (b)} is a column vector of size P containing the values of the parameters of the model representative of the re-sampled input signal,
Φ is a matrix of size Q*P wherein an element in a row q and a column p has a value p q-1 ,
x is a column vector of size Q containing samples of the re-sampled input signal, during a number Q of revolutions of the rotor.

5. The method as claimed in claim 2 , wherein determining a modeled input signal uses the following equation:
{circumflex over (x)}−Φ{circumflex over (b)}
wherein;
{circumflex over (b)} is a column vector of size P containing the values of the parameters of the model representative of the re-sampled input signal,
Φ is a matrix of size Q*P wherein an element in a row q and a column p has a value p q-1 ,
x is a column vector of size Q containing samples of the re-sampled input signal, during a number Q of revolutions of the rotor.

6. The method as claimed in claim 2 , wherein separating the filtered input signal comprises a windowing of the modeled input signal using different time-domain windows.

7. The method as claimed in claim 6 , wherein separating the filtered input signal uses the following equation:
{circumflex over (x)} r [n]={circumflex over (x)}[n]F ( r−r/R )

wherein:
{circumflex over (x)} r [n] is a sample n of the third component associated with the blade r,
{circumflex over (x)}[n] is a sample n of the modeled input signal,
F(r)=Σ q=1 Q f[n−q·N] with

f
·

[
n
]

=

{

1

if

-

r
/
2

⁢

R

≤
n
≤

r
/
2

⁢
R

0

elsewhere

 is a windowed signal associated with the blade r,
Q is a number of revolutions of the rotor during a total duration of the modeled input signal,
R is a total number of blades of the rotor.

8. The method as claimed in claim 1 , wherein detecting, in a third component, a rub between the blade associated with the third component and the stator, comprises determining an energy of the third component over at least one first revolution of the rotor and comparing the determined energy with a given threshold.

9. The method as claimed in claim 8 , wherein determining the energy of the third component uses the following equation:

I
r

[
q
]

=

1
N

⁢

∑

n
¯

=
1

N

x
^

r

[

n
¯

+

(

q
-
1

)

·
N

]

2

wherein:
I r [q] is a value of the energy, over a revolution q of the rotor, of the

Assignees

• Safran
• Safran Aircraft Engines

Inventors

• Abboud Dany
• El Badaoui Mohammed
• Tableau Nicolas Paul

Classifications

• F05D2260/80

  Diagnostics · CPC title

• F01D21/003

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• F01D21/04

  responsive to undesired position of rotor relative to stator {or to breaking-off of a part of the rotor}, e.g. indicating such position · CPC title

• G01M15/14 Primary

  Testing gas-turbine engines or jet-propulsion engines · CPC title