A method and system for analyzing response of an aero-engine rotor considering friction excitation

Abstract

The application relates to the technical field of aero-engines and discloses a method and system for analyzing the response of an aero-engine rotor considering friction excitation, wherein the vibration displacement unbalance responses of each axial position of a coupled double-rotor system under different unbalance amounts are obtained by applying unbalance amounts to a coupled double-rotor system dynamic model; the sensitivity of the unbalance responses of each axial position is used as the basis for determining the rubbing position; and a rubbing position rotor displacement linear superposition analysis model is constructed based on a rubbing force model and an unbalance force. The rotor displacement amount of the rubbing position under corresponding speed conditions is obtained by performing a sweep frequency analysis on the linear superposition analysis model under different speed input conditions through a chord cutting method, the accuracy of the rotor displacement amount of the double-rotor system is improved, and thus accurate basis is provided for reasonably optimizing and controlling the unbalance response of the engine.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and discloses a method and system for analyzing the rotor response of aero-engines considering frictional excitation. Background Technology

[0002] Rotor rubbing failure is one of the major failures in aero-engines. Once rubbing occurs between the rotor and stator, it can not only affect the normal operation and service life of the machinery, but also often cause very serious consequences. Moreover, in order to increase the output power of rotating machinery, the clearance between the rotor and stator is often reduced, which increases the possibility of rubbing between the rotor and stator. Therefore, it is necessary to study the system response caused by rotor-stator rubbing failure, both from the perspective of the reliability design of rotating machinery and to ensure the safe and stable operation of equipment.

[0003] Friction between rotating and stationary components is usually an indirect result of other faults, such as rotor mass imbalance, rotor bending, misalignment, insufficient clearance due to thermal expansion, and deformation caused by uneven heating of the stator. Friction between rotating and stationary components can be divided into two main categories: axial friction and radial friction. Radial friction occurs more frequently and has been the subject of more research. This paper focuses on radial friction.

[0004] In engineering, traditional rotor dynamic response analysis models often ignore friction and cannot accurately predict the nonlinear response caused by friction; existing simulation analysis models often use full-degree-of-freedom transient finite element simulation, which takes several hours for a single simulation and is difficult to use for parameter optimization design. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for analyzing the rotor response of an aero-engine that takes into account frictional excitation, which can improve the accuracy of rotor displacement in a dual-rotor system, thereby providing an accurate basis for the rational optimization and control of the engine's unbalanced response.

[0006] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0007] A method for analyzing the rotor response of an aero-engine considering frictional excitation, comprising: A dynamic model of a coupled dual-rotor system is established. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component, with support simulation components at both ends of the rotor shaft simulation component, and a high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. Based on the dynamic model of the coupled dual rotor system, the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalance quantities is obtained by using the principle of linear superposition. Based on the vibration displacement imbalance response corresponding to each imbalance quantity and each axial position, the sensitivity of each axial position is analyzed and obtained; the axial position with a sensitivity greater than the preset sensitivity threshold is determined as the rubbing position. A friction force model based on the blade rotation speed at the friction position is established, and a linear superposition analysis model of rotor displacement at the friction position is constructed based on the friction force model and the unbalanced force. Frequency sweep analysis was performed on the linear superposition analysis model under different speed input conditions, and the rotor displacement at the rubbing position under the corresponding speed conditions was obtained by the chord cutting method.

[0008] Furthermore, based on the aforementioned dynamic model of the coupled dual-rotor system, the following is adopted: The vibration displacement imbalance response of the coupled dual-rotor system at various axial positions under different imbalance values ​​was analyzed, among which... This is a response to vibration displacement imbalance. For the quality of the high-voltage disk simulation component, For the quality of the low-pressure disk simulation component, The natural frequency of the dual-rotor system, The rotational speed of the high-voltage disk simulation component. This represents the centroid offset of the high-pressure disk simulation component. The amount of imbalance applied, The imaginary unit, For the phase of the high-voltage disk simulation component, For time, The rotational speed of the low-pressure disk simulation component. This represents the centroid offset of the low-pressure disk simulation component. This refers to the phase of the low-pressure disk simulation component.

[0009] Furthermore, the sensitivity at each axial position ,in This represents the unbalanced vibration displacement response at each axial position of the dual-rotor system. The amount of imbalance applied, The change in unbalanced quantity The increment of the unbalanced vibration displacement response caused by the vibration.

[0010] Furthermore, the established rubbing force model based on the blade rotation speed at the rubbing position is as follows: ,in Output values ​​for the abrasion force model. The angular velocity of the rotor, The duration of the rubbing contact within one rotation cycle. The index variable is used for summation, representing the index of the first index. First harmonic, , This represents the upper limit of the harmonic order in the Fourier series expansion. Pi is the mathematical constant of a circle.

[0011] Furthermore, the linear superposition analysis model of rotor displacement at the rubbing position is as follows: ,in This represents the vibrational displacement of the rotor at the rubbing point. For the unbalanced torque of the dual-rotor system, , These are the linear response coefficients of the dual-rotor system.

[0012] To achieve the above-mentioned technical effects, the present invention also provides an aero-engine rotor response analysis system considering frictional excitation, used to implement the aforementioned aero-engine rotor response analysis method considering frictional excitation, comprising: The coupling model construction module is used to establish a dynamic model of a coupled dual-rotor system. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component, with support simulation components at both ends of the rotor shaft simulation component, and a high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. The response analysis module is used to analyze and obtain the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalance quantities based on the dynamic model of the coupled dual rotor system and the principle of linear superposition. The impact and rubbing position determination module is used to analyze and obtain the sensitivity of each axial position based on each unbalance and the vibration displacement unbalance response corresponding to each axial position; and to determine the axial position with a sensitivity greater than a preset sensitivity threshold as the impact and rubbing position. The displacement model construction module is used to establish a rubbing force model based on the blade rotation speed at the rubbing position, and to construct a linear superposition analysis model of rotor displacement at the rubbing position based on the rubbing force model and the unbalanced force. The displacement analysis module is used to perform frequency sweep analysis on the linear superposition analysis model under different speed input conditions, and obtain the rotor displacement at the rubbing position under the corresponding speed conditions by the chord cutting method.

[0013] Furthermore, the response analysis module adopts The vibration displacement imbalance response of the coupled dual-rotor system at various axial positions under different imbalance values ​​was analyzed, among which... This is a response to vibration displacement imbalance. For the quality of the high-voltage disk simulation component, For the quality of the low-pressure disk simulation component, The natural frequency of the dual-rotor system, The rotational speed of the high-voltage disk simulation component. This represents the centroid offset of the high-pressure disk simulation component. The amount of imbalance applied, The imaginary unit, For the phase of the high-voltage disk simulation component, For time, The rotational speed of the low-pressure disk simulation component. This represents the centroid offset of the low-pressure disk simulation component. This refers to the phase of the low-pressure disk simulation component.

[0014] Furthermore, in the module for determining the location of the impact, the sensitivity of each axial position... ,in This represents the unbalanced vibration displacement response at each axial position of the dual-rotor system. The amount of imbalance applied, The change in unbalanced quantity The increment of the unbalanced vibration displacement response caused by the vibration.

[0015] Furthermore, in the displacement model construction module, the established abrasion force model based on the blade rotation speed at the abrasion position is as follows: ,in Output values ​​for the abrasion force model. The angular velocity of the rotor, The duration of the rubbing contact within one rotation cycle. The index variable is used for summation, representing the index of the first index. First harmonic, , This represents the upper limit of the harmonic order in the Fourier series expansion. Pi is the mathematical constant of a circle.

[0016] Furthermore, in the displacement model construction module, the linear superposition analysis model of rotor displacement at the rubbing position is as follows: ,in This represents the vibrational displacement of the rotor at the rubbing point. For the unbalanced torque of the dual-rotor system, , These are the linear response coefficients of the dual-rotor system.

[0017] Compared with the prior art, the beneficial effects of this invention are as follows: This invention obtains the vibration displacement imbalance response of the coupled dual-rotor system at each axial position under different imbalance amounts by applying an imbalance amount to the dynamic model of the coupled dual-rotor system. The sensitivity of the imbalance response at each axial position is used as the basis for determining the rubbing position. Based on the rubbing force model and the imbalance force, a linear superposition analysis model of the rotor displacement at the rubbing position is constructed. By performing frequency sweep analysis on the linear superposition analysis model under different speed input conditions, the rotor displacement at the rubbing position under the corresponding speed conditions is obtained by the secant method, which improves the accuracy of the rotor displacement of the dual-rotor system, thereby providing an accurate basis for the rational optimization and control of the engine's imbalance response. Attached Figure Description

[0018] Figure 1 This is a flowchart of the aero-engine rotor response analysis method considering frictional excitation in Example 1 or 2; Figure 2 This is a block diagram of the aero-engine rotor response analysis system considering frictional excitation in Example 1; Figure 3 This is a schematic diagram of the dynamic model of the coupled dual-rotor system in Example 2; The module includes: 1. Coupled model construction module; 2. Response analysis module; 3. Collision position determination module; 4. Displacement model construction module; and 5. Displacement analysis module. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0020] Example 1 See Figure 1 and Figure 2 A method for analyzing the rotor response of an aero-engine considering frictional excitation, comprising: A dynamic model of a coupled dual-rotor system is established. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component, with support simulation components at both ends of the rotor shaft simulation component, and a high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. Based on the dynamic model of the coupled dual rotor system, the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalance quantities is obtained by using the principle of linear superposition. Based on the vibration displacement imbalance response corresponding to each imbalance quantity and each axial position, the sensitivity of each axial position is analyzed and obtained; the axial position with a sensitivity greater than the preset sensitivity threshold is determined as the rubbing position. A friction force model based on the blade rotation speed at the friction position is established, and a linear superposition analysis model of rotor displacement at the friction position is constructed based on the friction force model and the unbalanced force. Frequency sweep analysis was performed on the linear superposition analysis model under different speed input conditions, and the rotor displacement at the rubbing position under the corresponding speed conditions was obtained by the chord cutting method.

[0021] In this embodiment, by applying an unbalanced amount to the dynamic model of the coupled dual-rotor system, the vibration displacement unbalanced response of the coupled dual-rotor system at each axial position under different unbalanced amounts is obtained. The sensitivity of the unbalanced response at each axial position is used as the basis for determining the rubbing position. Based on the rubbing force model and the unbalanced force, a linear superposition analysis model of the rotor displacement at the rubbing position is constructed. By performing frequency sweep analysis on the linear superposition analysis model under different speed input conditions, the rotor displacement at the rubbing position under the corresponding speed conditions is obtained by the secant method, which improves the accuracy of the rotor displacement of the dual-rotor system, thereby providing an accurate basis for the reasonable optimization and control of the engine's unbalanced response.

[0022] Based on the same inventive concept, this embodiment also provides an aero-engine rotor response analysis system considering frictional excitation, used to implement the aforementioned aero-engine rotor response analysis method considering frictional excitation, including: The coupling model construction module 1 is used to establish a dynamic model of a coupled dual-rotor system. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component, with support simulation components at both ends of the rotor shaft simulation component, and a high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. Response analysis module 2 is used to analyze and obtain the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalance quantities based on the dynamic model of the coupled dual rotor system and the principle of linear superposition. The rubbing position determination module 3 is used to analyze and obtain the sensitivity of each axial position based on each unbalance and the vibration displacement unbalance response corresponding to each axial position; and to determine the axial position with a sensitivity greater than a preset sensitivity threshold as the rubbing position. The displacement model construction module 4 is used to establish a rubbing force model based on the blade rotation speed at the rubbing position, and to construct a linear superposition analysis model of rotor displacement at the rubbing position based on the rubbing force model and the unbalanced force. The displacement analysis module 5 is used to perform frequency sweep analysis on the linear superposition analysis model under different speed input conditions, and obtain the rotor displacement at the rubbing position under the corresponding speed conditions by the chord cutting method.

[0023] Example 2 See Figure 1 , Figure 3 A method for analyzing the rotor response of an aero-engine considering frictional excitation, comprising: Step 1: Establish a dynamic model of the coupled dual-rotor system. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component. Support simulation components are provided at both ends of the rotor shaft simulation component. A high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. In this embodiment, the dynamic model of the dual-rotor system is as follows: Figure 3As shown, the dual-rotor system has a shaft length of L, and two disks (high-pressure disk and low-pressure disk) are installed in the middle of the shaft, representing the high-pressure turbine and the low-pressure turbine, respectively.

[0024] Step 2: Based on the dynamic model of the coupled dual rotor system, the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalances is obtained by analyzing the linear superposition principle. In this embodiment, the vibration displacement response of the rotor at various positions along the axial direction is considered as the dependent variable, while the unbalanced force of the rotor system is considered as the independent variable. Applying the principle of linear superposition, under a certain unbalanced amount e excitation, the following is used: The vibration displacement imbalance response of the coupled dual-rotor system at various axial positions under different imbalance values ​​was analyzed, among which... This is a response to vibration displacement imbalance. For the quality of the high-voltage disk simulation component, For the quality of the low-pressure disk simulation component, The natural frequency of the dual-rotor system, The rotational speed of the high-voltage disk simulation component. This represents the centroid offset of the high-pressure disk simulation component. The amount of imbalance applied, The imaginary unit, For the phase of the high-voltage disk simulation component, For time, The rotational speed of the low-pressure disk simulation component. This represents the centroid offset of the low-pressure disk simulation component. This refers to the phase of the low-pressure disk simulation component.

[0025] Step 3: Based on the unbalanced quantity and the vibration displacement unbalanced response corresponding to each axial position, analyze and obtain the sensitivity of each axial position; determine the axial position with a sensitivity greater than the preset sensitivity threshold as the rubbing position; In this embodiment, since the imbalance response at each location increases linearly with the imbalance amount e, the system's sensitivity to the imbalance can be obtained by evaluating the absolute value of the response at each point. Sensitivity at each axial position. ,in This represents the unbalanced vibration displacement response at each axial position of the dual-rotor system. The amount of imbalance applied, The change in unbalanced quantity The increment of the unbalanced vibration displacement response caused by the vibration.

[0026] By conducting sensitivity analysis and evaluation of the engine rotor system, it becomes an important basis for optimizing the rotor system dynamics. By correctly selecting and adjusting the support stiffness, it can be determined whether to install elastic damping supports and their installation positions, thereby obtaining the optimal layout of elastic dampers and rationally optimizing and controlling the engine's unbalanced response.

[0027] Step 4: Establish a rubbing force model based on the blade rotation speed at the rubbing position, and construct a linear superposition analysis model of rotor displacement at the rubbing position based on the rubbing force model and the unbalanced force. In this embodiment, multiple blades are considered to rub against the casing, and a blade-casing rubbing force model is established. Since the blades come into contact with stationary components during a portion of the precession cycle and transient processes are ignored, the rubbing force model can be modeled as a periodic step function. ,in Output values ​​for the abrasion force model. The angular velocity of the rotor, The duration of the rubbing contact within one rotation cycle. The index variable is used for summation, representing the index of the first index. First harmonic, , This represents the upper limit of the harmonic order in the Fourier series expansion. Pi is the mathematical constant of a circle.

[0028] Step 5: Perform frequency sweep analysis on the linear superposition analysis model under different speed input conditions, and obtain the rotor displacement at the rubbing position under the corresponding speed conditions by the chord cut method; In this embodiment, the linear superposition analysis model of rotor displacement at the rubbing position is as follows: ,in This represents the vibrational displacement of the rotor at the rubbing point. For the unbalanced torque of the dual-rotor system, , These are the linear response coefficients of the dual-rotor system.

[0029] Solving the equation using the secant method Complex roots: A) Initialization: Given two initial guessed values ​​S (0) and S (1) And set the allowable convergence tolerance. .

[0030] B) Iterative calculation: For the k-th iteration (k=1,2,...), calculate the residual R. (k) If |R (k) ∣< Then the iteration converges, S (k) This is the solution; otherwise, update the guessed value according to the secant method formula:

[0031] C) Output: The converged solution This represents the rotor vibration displacement at the rubbing position at that rotational speed. D) Frequency sweep analysis: Traverse the range of speeds of interest, and repeat step one for each speed Ω to obtain the response curve of rotor displacement as a function of speed.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for analyzing the rotor response of an aero-engine considering frictional excitation, characterized in that, include: A dynamic model of a coupled dual-rotor system is established. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component, with support simulation components at both ends of the rotor shaft simulation component, and a high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. Based on the dynamic model of the coupled dual rotor system, the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalance quantities is obtained by using the principle of linear superposition. Based on the vibration displacement imbalance response corresponding to each imbalance quantity and each axial position, the sensitivity of each axial position is analyzed and obtained; the axial position with a sensitivity greater than the preset sensitivity threshold is determined as the rubbing position. A friction force model based on the blade rotational speed at the friction position is established, and a linear superposition analysis model of rotor displacement at the friction position is constructed based on the friction force model and the unbalanced force; wherein the established friction force model based on the blade rotational speed at the friction position is as follows: ,in Output values ​​for the abrasion force model. The angular velocity of the rotor, The duration of the rubbing contact within one rotation cycle. The index variable is used for summation, representing the index of the first index. First harmonic, , This represents the upper limit of the harmonic order in the Fourier series expansion. Pi; Frequency sweep analysis was performed on the linear superposition analysis model under different speed input conditions, and the rotor displacement at the rubbing position under the corresponding speed conditions was obtained by the chord cutting method.

2. The method for analyzing the rotor response of an aero-engine considering frictional excitation according to claim 1, characterized in that, Based on the dynamic model of the coupled dual-rotor system, the following is adopted: The vibration displacement imbalance response of the coupled dual-rotor system at various axial positions under different imbalance values ​​was analyzed, among which... This is a response to vibration displacement imbalance. For the quality of the high-voltage disk simulation component, For the quality of the low-pressure disk simulation component, The natural frequency of the dual-rotor system, The rotational speed of the high-voltage disk simulation component. This represents the centroid offset of the high-pressure disk simulation component. The amount of imbalance applied, The imaginary unit, For the phase of the high-voltage disk simulation component, For time, The rotational speed of the low-pressure disk simulation component. This represents the centroid offset of the low-pressure disk simulation component. This refers to the phase of the low-pressure disk simulation component.

3. The method for analyzing the rotor response of an aero-engine considering frictional excitation according to claim 1, characterized in that, Sensitivity at each axial position ,in This represents the unbalanced vibration displacement response at each axial position of the dual-rotor system. The amount of imbalance applied, The change in unbalanced quantity The increment of the unbalanced vibration displacement response caused by the vibration.

4. The method for analyzing the rotor response of an aero-engine considering frictional excitation according to claim 1, characterized in that, The linear superposition analysis model of rotor displacement at the rubbing position is as follows: ,in This represents the vibrational displacement of the rotor at the rubbing point. For the unbalanced torque of the dual-rotor system, , These are the linear response coefficients of the dual-rotor system.

5. A rotor response analysis system for an aero-engine considering frictional excitation, used to implement the rotor response analysis method for an aero-engine considering frictional excitation as described in claim 1, characterized in that, include: The coupling model construction module is used to establish a dynamic model of a coupled dual-rotor system. The dynamic model of the coupled dual-rotor system includes a rotor shaft simulation component, with support simulation components at both ends of the rotor shaft simulation component, and a high-pressure disk simulation component and a low-pressure disk simulation component are provided on the rotor shaft simulation component. The response analysis module is used to analyze and obtain the vibration displacement imbalance response of the coupled dual rotor system at each axial position under different imbalance quantities based on the dynamic model of the coupled dual rotor system and the principle of linear superposition. The impact and rubbing position determination module is used to analyze and obtain the sensitivity of each axial position based on each unbalance and the vibration displacement unbalance response corresponding to each axial position; and to determine the axial position with a sensitivity greater than a preset sensitivity threshold as the impact and rubbing position. The displacement model construction module is used to establish a rubbing force model based on the blade rotation speed at the rubbing position, and to construct a linear superposition analysis model of rotor displacement at the rubbing position based on the rubbing force model and the unbalanced force; wherein the established rubbing force model based on the blade rotation speed at the rubbing position is as follows: ,in Output values ​​for the abrasion force model. The angular velocity of the rotor, The duration of the rubbing contact within one rotation cycle. The index variable is used for summation, representing the index of the first index. First harmonic, , This represents the upper limit of the harmonic order in the Fourier series expansion. Pi; The displacement analysis module is used to perform frequency sweep analysis on the linear superposition analysis model under different speed input conditions, and obtain the rotor displacement at the rubbing position under the corresponding speed conditions by the chord cutting method.

6. The aero-engine rotor response analysis system considering frictional excitation according to claim 5, characterized in that, The response analysis module adopts The vibration displacement imbalance response of the coupled dual-rotor system at various axial positions under different imbalance values ​​was analyzed, among which... This is a response to vibration displacement imbalance. For the quality of the high-voltage disk simulation component, For the quality of the low-pressure disk simulation component, The natural frequency of the dual-rotor system, The rotational speed of the high-voltage disk simulation component. This represents the centroid offset of the high-pressure disk simulation component. The amount of imbalance applied, The imaginary unit, For the phase of the high-voltage disk simulation component, For time, The rotational speed of the low-pressure disk simulation component. This represents the centroid offset of the low-pressure disk simulation component. This refers to the phase of the low-pressure disk simulation component.

7. The aero-engine rotor response analysis system considering frictional excitation according to claim 5, characterized in that, Sensitivity of each axial position in the collision location determination module ,in This represents the unbalanced vibration displacement response at each axial position of the dual-rotor system. The amount of imbalance applied, The change in unbalanced quantity The increment of the unbalanced vibration displacement response caused by the vibration.

8. The aero-engine rotor response analysis system considering frictional excitation according to claim 5, characterized in that, In the displacement model construction module, the linear superposition analysis model of rotor displacement at the contact / grinding position is as follows: ,in This represents the vibrational displacement of the rotor at the rubbing point. For the unbalanced torque of the dual-rotor system, , These are the linear response coefficients of the dual-rotor system.

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