CN-121997444-A - Method for adjusting bending critical rotation speed of aero-engine rotor based on mode shape

CN121997444ACN 121997444 ACN121997444 ACN 121997444ACN-121997444-A

Abstract

The embodiment of the invention provides a mode-shape-based method for adjusting the bending critical rotation speed of an aero-engine rotor, and relates to the field of high-pressure rotors of aero-engines. The method aims to solve the problems of complex process and high cost of the adjustment of the critical bending rotation speed of the engine rotor by changing the elastic supporting rigidity and the structural parameters of the rotor. The method comprises the step of adjusting the bending critical rotation speed of the engine rotor by adjusting the local mass of a deformation sensitive area of the engine rotor, wherein the deformation sensitive area refers to the area with the largest bending mode deformation. The bending critical rotation speed of the engine rotor is controllably adjusted in the deformation sensitive area of the engine rotor through adjusting the mass, and the adjusting mode can simply and efficiently adjust and test and verify the bending critical rotation speed, so that the design margin of the bending critical rotation speed of the engine is conveniently obtained.

Inventors

ZHANG NA
WANG WEN
HU JIALIN

Assignees

中国航发商用航空发动机有限责任公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (10)

1. The method for adjusting the bending critical rotation speed of the aero-engine rotor based on the mode shape is characterized by comprising the following steps of: And adjusting the bending critical rotation speed of the engine rotor by adjusting the local mass of a deformation sensitive area of the engine rotor, wherein the deformation sensitive area refers to the maximum deformation area of the bending mode.
2. The method for adjusting the bending critical rotational speed of an aircraft engine rotor based on the mode shape according to claim 1, wherein the step of adjusting the bending critical rotational speed of the engine rotor by adjusting the local mass of the deformation sensitive area of the engine rotor comprises the steps of: obtaining a deformation sensitive area of the engine rotor through bending mode analysis of the engine rotor; establishing an engine rotor critical rotation speed simulation analysis model, and respectively carrying out bending critical rotation speed analysis by adding adjusting pieces with different masses in a deformation sensitive area of an engine rotor to obtain bending critical rotation speeds and design margins corresponding to the different masses; And according to the simulation analysis result of the critical rotation speed of the engine rotor, performing an engine rotor dynamic characteristic test, and verifying the bending critical rotation speed and the design margin corresponding to different masses obtained by model analysis to obtain a sensitivity curve of the bending critical rotation speed of the rotor and the local mass of the deformation sensitive region.
3. The method for adjusting the bending critical rotation speed of the rotor of the aeroengine based on the mode shape according to claim 2, wherein the step of obtaining the deformation sensitive area of the rotor of the engine through the analysis of the bending mode of the rotor of the engine comprises the following steps: And obtaining a deformation sensitive area of the high-pressure rotor of the aero-engine as the front end of the front shaft diameter through bending mode analysis of the high-pressure rotor of the aero-engine.
4. The method for adjusting the bending critical rotation speed of the aeroengine rotor based on the mode shape is characterized in that the adjusting piece is fixed with the front end of the front shaft diameter through a transfer shaft, a plurality of positioning pin holes are formed in the front end of the front shaft diameter in the circumferential direction, a plurality of positioning holes are formed in the outer ring of the transfer shaft in the circumferential direction, a plurality of threaded holes are formed in the inner ring of the transfer shaft in the circumferential direction, the positioning holes correspond to the positioning pin holes in position and are abutted and fixed through locking nuts after being positioned through positioning pins, the locking nuts are in threaded connection with the front end of the front shaft diameter, and a plurality of bolt mounting holes are formed in the adjusting piece in the circumferential direction and correspond to the threaded holes and are fixed through screws.
5. The method for adjusting the bending critical rotation speed of the aero-engine rotor based on the mode shape according to claim 4, wherein the adjusting piece is an adjusting shaft, the adjusting shaft comprises a first section of shaft, one end of the first section of shaft is circumferentially provided with a connecting flange, the connecting flange is circumferentially provided with a plurality of bolt mounting holes, and the axial length of the first section of shaft is a variable of different mass adjustment.
6. The method for adjusting the bending critical rotation speed of an aeroengine rotor based on a mode shape according to claim 5, wherein the adjusting shaft comprises a second section shaft, the diameter of the second section shaft is larger than that of the first section shaft, the second section shaft is coaxially fixed with the first section shaft, the second section shaft is positioned at one end, far away from the connecting flange, of the first section shaft, and the diameter and the axial length of the second section shaft are variables for adjusting different qualities.
7. The method for adjusting the critical bending rotational speed of an aeroengine rotor based on the mode shape according to any one of claims 2 to 6, wherein the step of establishing an engine rotor critical rotational speed simulation analysis model, and respectively performing the critical bending rotational speed analysis by adding adjusting pieces with different masses in a deformation sensitive area of the engine rotor to obtain the critical bending rotational speed and the design margin corresponding to the different masses comprises the following steps: Establishing a critical rotation speed analysis model of an engine rotor; calculating a bending critical rotation speed Nc0 and a design margin M0 of a maximum working rotation speed Nwmax under an initial working condition 0 state, wherein M0= (Nc 0-Nwmax)/Nwmax; Calculating a bending critical rotation speed Ncmin in a state of increasing the maximum mass adjusting piece and a minimum design margin Mmin from a maximum working rotation speed Nwmax, wherein Mmin= (Ncmin-Nwmax)/Nwmax, and the minimum design margin Mmin is less than or equal to-10%; Calculating design margin Mi of bending critical rotation speed Nci and distance maximum working rotation speed Nwmax obtained by adding different mass adjusting piece analysis under different working conditions, wherein Mi= (Nci-Nwmax)/Nwmax; And obtaining the bending critical rotation speed and design margin corresponding to different masses according to the Mmin less than or equal to Mi < M0.
8. The method for adjusting the critical bending rotational speed of an aero-engine rotor based on the mode shape according to any one of claims 2 to 6, wherein the step of performing an engine rotor dynamic characteristic test according to the results of the simulation analysis of the critical rotational speed of the engine rotor, verifying the critical bending rotational speed and the design margin corresponding to different masses obtained by the model analysis, and obtaining a sensitivity curve of the critical bending rotational speed of the rotor and the local mass of the deformation sensitive region comprises the following steps: Verifying the simulation analysis result of the critical rotation speed of the engine rotor by a real object, carrying out a sweep test under the initial working condition 0, and assembling adjusting pieces with different qualities of the engine rotor according to the sequence from small to large, and respectively carrying out the sweep test to obtain the bending critical rotation speed falling in the maximum working rotation speed range; And drawing a sensitivity curve according to the obtained relation between the bending critical rotation speed and the local mass of the deformation sensitive area.
9. The method for adjusting the bending critical rotation speed of the aero-engine rotor based on the mode shape according to claim 8, wherein the step of performing an engine rotor dynamic characteristic test according to the simulation analysis result of the critical rotation speed of the engine rotor, verifying the bending critical rotation speed and the design margin corresponding to different masses obtained by the model analysis, and obtaining the sensitivity curve of the bending critical rotation speed of the rotor and the local mass of the deformation sensitive region further comprises: Calculating a deviation value between a bending critical rotating speed obtained by actual measurement of an engine rotor dynamic characteristic test and a bending critical rotating speed obtained by simulation analysis result of the engine rotor critical rotating speed; and adjusting the design margin according to the deviation value.
10. The method for adjusting the bending critical rotation speed of the rotor of the aeroengine based on the mode shape according to claim 9, wherein the initial working condition 0 state is a state that an adjusting piece is not added to the rotor of the engine.

Description

Method for adjusting bending critical rotation speed of aero-engine rotor based on mode shape Technical Field The invention relates to the field of high-pressure rotors of aero-engines, in particular to a mode-shape-based method for adjusting the critical bending rotating speed of an aero-engine rotor. Background The aeroengine rotor dynamics design is one of core technologies of aeroengine design, and the reasonable configuration of the critical rotation speed of a rotor supporting system is an important precondition for ensuring the safe and reliable operation of the engine. For the high-pressure rotor of the aero-engine, a certain design criterion is required to be complied with when the critical rotation speed design is carried out, wherein one of the important items is that the bending critical rotation speed of the rotor is adjusted to be above the maximum working rotation speed of the engine, and a certain safety margin is reserved. The critical bending rotation speed means that the rotor presents a vibration mode with larger bending, at the moment, the bending strain energy of the rotor is generally higher, on one hand, the vibration mode is very sensitive to unbalanced excitation, on the other hand, the strain energy of the engine is concentrated on the rotor, the deformation of a stator part is small, and the participation of vibration and the absorption of vibration energy are smaller. Therefore, it is important that the operating speed range avoid the bending threshold speed. With the increasing thrust-weight ratio of aeroengines, engines are required to meet the requirements of safe operation under lighter structural weight. The maximum rotational speed of the engine rotor is limited by static strength of the rotor and the like, and the maturity of the rotor dynamics analysis method is improved, so that the difference between the critical rotational speed analysis result and the actual measurement result is smaller. At this time, whether or not the safety margin of the bending critical rotation speed design can be reduced, to a small extent, all needs to be verified through experiments. Conventional methods of critical speed adjustment for engine rotor-support systems include adjusting the stiffness of the elastomeric support, changing rotor structural parameters to adjust rotor stiffness. The rigidity adjustable range of the elastic support is limited, the process of changing and loading the elastic support is complex, the time period is long, the rotor needs to be reprocessed and replaced when the structural parameters of the rotor are changed, and the cost is high. Disclosure of Invention The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. The invention aims to provide an aircraft engine rotor bending critical rotation speed adjusting method based on a mode shape, which can solve the problems of complex process and high cost caused by changing the elastic supporting rigidity and the rotor structural parameters of the adjustment of the engine rotor bending critical rotation speed. Embodiments of the invention may be implemented as follows: the embodiment of the invention provides a mode-shape-based aero-engine rotor bending critical rotation speed adjusting method, which comprises the step of adjusting the bending critical rotation speed of an engine rotor by adjusting the local mass of a deformation sensitive area of the engine rotor, wherein the deformation sensitive area refers to the area with the largest bending mode deformation. In addition, the method for adjusting the bending critical rotation speed of the aero-engine rotor based on the mode shape, provided by the embodiment of the invention, can also have the following additional technical characteristics: Optionally, the step of adjusting the bending critical rotation speed of the engine rotor by adjusting the local mass of the deformation sensitive region of the engine rotor comprises: The method comprises the steps of obtaining a deformation sensitive area of an engine rotor through engine rotor bending mode analysis, establishing an engine rotor critical speed simulation analysis model, respectively carrying out bending critical speed analysis by adding adjusting pieces with different masses in the deformation sensitive area of the engine rotor to obtain bending critical speeds and design margins corresponding to the different masses, carrying out an engine rotor dynamic characteristic test according to an engine rotor critical speed simulation analysis result, and verifying the bending critical speeds and the