Turbine bucket assembly compression state design method based on strain energy distribution optimization

Abstract

The application belongs to the technical field of aerospace engine, and particularly relates to a turbine baffle assembly compression state design method based on strain energy distribution optimization, comprising: obtaining initial assembly parameters of a turbine baffle assembly; obtaining different working conditions of the turbine baffle assembly; establishing a finite element model of the turbine baffle assembly; determining strain energy distribution of turbine baffle assembly; determining strain energy distribution of turbine baffle assembly under each working condition; judging whether the assembly strain energy realizes fixed point release under each working condition, if not, continue to optimize the turbine baffle configuration on the basis of meeting the quality requirements; otherwise, proceed to the next step; turbine baffle strength analysis. The application optimizes the turbine baffle configuration based on strain energy distribution, realizes fixed point release of assembly strain energy, ensures the compression state of turbine baffle to turbine blade-disk under each working condition, avoids sealing failure, and improves the reliability of the turbine baffle assembly on the basis of meeting the quality requirements.

Description

Technical Field

[0001] This invention belongs to the field of aerospace engine technology, specifically relating to a design method for the clamping state of a turbine baffle assembly based on strain energy distribution optimization. Background Technology

[0002] Driven by the need for high structural efficiency, modern advanced aero-engine turbine damper assemblies often employ a boltless damper design. This means that multiple components, including the turbine disk, blades, and integrated sealing disk-damper, utilize their own elastic pre-deformation to mutually compress and constrain each other, forming a structural system with relatively independent functions. To ensure the cooling effect of the turbine blade-disk (turbine blades and turbine disk), the turbine damper needs to press the turbine disk tightly to ensure proper sealing. However, due to the complex and variable operating conditions of the turbine damper assembly, inconsistencies in deformation between components under different operating conditions may lead to sealing failure of the turbine damper assembly, thereby affecting the cooling effect of the turbine blade-disk and potentially causing engine malfunction.

[0003] Existing turbine baffle designs are primarily based on strength design principles, using strength verification methods to ensure the baffles meet fatigue and creep strength requirements. However, these methods cannot guarantee the proper sealing function of the turbine baffle assembly under all operating conditions, and the sealing function of the turbine baffle assembly depends on the pressure state of the turbine baffle on the turbine blade-disk. The design must ensure that the pressure state of the turbine baffle on the turbine blade-disk is not excessive under all operating conditions to avoid interface damage, while also ensuring that the turbine baffle maintains constant pressure on the turbine blade-disk to guarantee sealing. Therefore, ensuring the pressure state of the turbine baffle assembly under all operating conditions through design is crucial. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for designing the clamping state of a turbine baffle assembly based on strain energy distribution optimization.

[0005] This invention is implemented by providing a method for designing the clamping state of a turbine baffle assembly based on strain energy distribution optimization, comprising the following steps: Step 1: Obtain the initial assembly parameters of the turbine baffle assembly; Step 2: Obtain different operating conditions for the turbine baffle assembly; Step 3: Establish the finite element model of the turbine baffle assembly; Step 4: Obtain the assembly strain energy distribution of the turbine baffle using the finite element model from Step 3; Step 5: Based on the working conditions in Step 2 and using the finite element model in Step 3, obtain the assembly strain energy distribution of the turbine baffle under different working conditions. Step 6: Determine whether the assembly strain energy of the turbine baffle has been released at a fixed point under different working conditions. If it has not been released at a fixed point, optimize the turbine baffle configuration while meeting the quality requirements, and repeat steps 3-6; if it has been released at a fixed point, proceed to the next step. Step 7: Strength analysis of the turbine baffle assembly.

[0006] Preferably, in step 1, the initial assembly parameters include the initial assembly preload and the initial interference fit of the cylindrical mating surface.

[0007] Preferably, in step 2, the operating conditions are determined by the turbine baffle assembly's designed operating speed, operating temperature distribution, and external load spectrum; different operating conditions include ground idle state, air idle state, hot weather takeoff state, and emergency state.

[0008] Preferably, step 3 includes the following steps: Step 3.1: Obtain the 3D model of the turbine baffle assembly; Step 3.2: Based on the initial assembly parameters in Step 1, establish the finite element model of the turbine baffle assembly.

[0009] Preferably, step 6 includes the following steps: Step 6.1: Based on the assembly strain energy distribution of the turbine baffle in Step 4, determine the location of concentrated assembly strain energy; Step 6.2: Based on the distribution of assembly strain energy of the turbine baffle under different working conditions in Step 5, determine the location of concentrated assembly strain energy under different working conditions. Step 6.3: If the release position of the assembly strain energy is not on the pressing end face of the turbine baffle on the turbine blade-disk under different working conditions, optimize the turbine baffle configuration on the basis of meeting the quality requirements, and repeat steps 3-6; if the release position of the assembly strain energy is on the pressing end face of the turbine baffle on the turbine blade-disk under different working conditions, the fixed-point release of the assembly strain energy is achieved, the optimization is completed, and continue to the next step.

[0010] Further preferably, in step 6.3, optimizing the turbine baffle configuration includes the following: Based on the original turbine baffle configuration, a sealing tip is added; if a sealing tip already exists, the length of the sealing tip is changed. If the original turbine baffle configuration is an integrated sealing disc-baffle structure, the configuration of the transition section between the sealing disc and the turbine baffle is optimized based on the original turbine baffle configuration, including the tilt angle, the curvature of the transition section, the axial length, and the radial thickness.

[0011] Further preferred, in step 6.3, meeting the quality requirements means that, according to actual engineering needs, the weight increase of the turbine baffle assembly improvement does not exceed 1%.

[0012] Preferably, step 7 includes the following steps: Step 7.1: Based on the optimized turbine baffle configuration in Step 6 and the initial assembly parameters in Step 1, establish a finite element model of the turbine baffle assembly; Step 7.2: Perform strength verification.

[0013] Compared with the prior art, the advantages of the present invention are as follows: This invention optimizes the turbine baffle configuration based on strain energy distribution, achieving targeted release of assembly strain energy and ensuring the baffle's compression of the turbine blade-disk under various operating conditions, thereby avoiding sealing failure and improving the reliability of the turbine baffle assembly while meeting quality requirements. Attached Figure Description

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: Figure 1 A simplified flowchart of a turbine baffle assembly clamping state design method based on strain energy distribution optimization provided by the present invention; Figure 2 This is a schematic diagram of the original scheme of the integrated sealing disc-baffle structure of the turbine baffle assembly in an embodiment of the present invention; Figure 3 This is a schematic diagram of the axial deformation of the original scheme of the integrated sealing disc-baffle structure of the turbine baffle assembly in an emergency state, as shown in this embodiment of the invention. Figure 4 This is a schematic diagram comparing the original and optimized schemes of the integrated sealing disc-baffle structure of the turbine baffle assembly in an embodiment of the present invention; Figure 5 This is a schematic diagram of the strain energy distribution of the integrated sealing disc-baffle structure of the turbine baffle assembly in the assembled state in this embodiment of the invention. Figure 6 This is a schematic diagram of the strain energy distribution of the original scheme of the integrated sealing disc-baffle structure of the turbine baffle assembly in an emergency state, as shown in this embodiment of the invention. Figure 7 This is a schematic diagram of strain energy distribution of the integrated sealing disc-baffle structure optimization scheme of the turbine baffle assembly in the assembled state in an embodiment of the present invention; Figure 8 This is a schematic diagram of strain energy distribution of the integrated sealing disc-baffle structure optimization scheme of the turbine baffle assembly under emergency conditions in an embodiment of the present invention; The components are: 1. Sealing disc; 2. Transition section; 3. Turbine baffle; 4. Turbine blade; 5. Turbine disk; 6. Sealing tip; 7. First arc section; 8. Straight section; 9. Second arc section; 10. Pressing end face; 11. Original strain energy distribution concentration location of the integrated sealing disc-baffle structure of the turbine baffle assembly in the assembled state; 12. Original strain energy distribution concentration location of the integrated sealing disc-baffle structure of the turbine baffle assembly in the emergency state; 13. Optimized strain energy distribution concentration location of the integrated sealing disc-baffle structure of the turbine baffle assembly in the assembled state; 14. Optimized strain energy distribution concentration location of the integrated sealing disc-baffle structure of the turbine baffle assembly in the emergency state. Detailed Implementation

[0015] Various exemplary embodiments of the invention will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are not intended to limit the invention or its application or use in any way. The invention can be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0016] refer to Figure 1 This invention provides a method for designing the clamping state of a turbine baffle assembly based on strain energy distribution optimization, comprising the following steps: Step 1: Obtain the initial assembly parameters of the turbine baffle assembly, including the initial assembly preload and the initial interference fit of the cylindrical mating surfaces; Step 2: Obtain different operating conditions of the turbine baffle assembly, namely the mechanical and thermal load conditions at various locations of the turbine baffle assembly, which are determined by the turbine baffle assembly's design operating speed, operating temperature distribution, and external load spectrum; specifically, the operating conditions include ground idle state, air idle state, hot weather takeoff state, and emergency state, etc. Step 3: Establish the finite element model of the turbine baffle assembly; specifically including the following steps: Step 3.1: Obtain the 3D model of the turbine baffle assembly; Step 3.2: Based on the initial assembly parameters in Step 1, establish the finite element model of the turbine baffle assembly; Step 4: Obtain the assembly strain energy distribution of the turbine baffle using the finite element model from Step 3; Step 5: Based on the working conditions in Step 2 and using the finite element model in Step 3, obtain the assembly strain energy distribution of the turbine baffle under each working condition. Step 6: Determine whether the assembly strain energy of the turbine baffle has been released at a fixed point under different operating conditions. If it has not been released at a fixed point, optimize the turbine baffle configuration while meeting the quality requirements, and repeat steps 3-6; otherwise, proceed to the next step. Specifically, this includes the following steps: Step 6.1: Based on the assembly strain energy distribution of the turbine baffle in Step 4, determine the location of concentrated assembly strain energy; Step 6.2: Based on the distribution of assembly strain energy of the turbine baffle under different working conditions in Step 5, determine the location of concentrated assembly strain energy under different working conditions. Step 6.3: If the release location of the assembly strain energy under different operating conditions is not at the pressing end face of the turbine baffle on the turbine blade-disk, then optimize the turbine baffle configuration while meeting the quality requirements, and repeat steps 3-6; if the release location of the assembly strain energy under different operating conditions is at the pressing end face of the turbine baffle on the turbine blade-disk, then the fixed-point release of the assembly strain energy has been achieved, the optimization is complete, and proceed to the next step; among which, optimizing the turbine baffle configuration includes the following: Based on the original turbine baffle configuration, a sealing tip is added; if a sealing tip already exists, the length of the sealing tip is changed. If the original turbine baffle configuration is an integrated sealing disc-baffle structure, the configuration of the transition section between the sealing disc and the baffle is optimized based on the original turbine baffle configuration, including the tilt angle, the curvature of the transition section, the axial length, and the radial thickness. In one specific embodiment, the original turbine baffle configuration is an integrated sealing disc-baffle structure, such as... Figure 2 As shown, the sealing disc 1 and the turbine baffle 3 are connected by the transition section 2, forming an integrated sealing disc-baffle structure, which, together with the turbine blade 4 and the turbine disk 5 (the turbine blade 4 and the turbine disk 5 form the turbine blade-disk), constitutes the turbine baffle assembly. Figure 3 As shown, in an emergency, the integrated sealing disc-baffle structure of the turbine baffle assembly undergoes axial deformation, and the turbine baffle 3 separates from the clamping end face 10 of the turbine blade-disk. This indicates that the release location of the assembly strain energy in an emergency is not at the position of the turbine baffle 3 relative to the clamping end face 10, requiring optimization of the turbine baffle configuration. Based on experience, when the concentrated location of the turbine baffle assembly strain energy is at the first arc segment 7 and the straight segment 8 in the transition section 2, the release location of the assembly strain energy in an emergency will be at the clamping end face 10. Based on the strain energy distribution, the turbine baffle can be optimized, such as... Figure 4As shown, the original and optimized schemes are represented by dashed lines of different shapes. It can be seen that compared to the original scheme, the optimized scheme adds a sealing tip 6, lengthens the axial length of the straight section 8 (along the engine gas flow direction), and changes the curvature of the first arc section 7, making it exhibit a "reverse-fold" shape. Furthermore, it thickens the radial thickness of the straight section 8 and the second arc section 9. Before optimization, the strain energy distribution concentration position 11 of the integrated sealing disc-baffle structure of the turbine baffle assembly in the assembled state is as follows: Figure 5 As shown, the original design of the integrated sealing disc-baffle structure of the turbine baffle assembly under emergency conditions has a concentrated strain energy distribution at location 12. Figure 6 As shown, it almost encompasses the entire turbine baffle 3 and transition section 2. After optimization, the strain energy distribution concentration location 13 of the integrated sealing disc-baffle structure optimization scheme of the turbine baffle assembly in the assembled state is as follows: Figure 7 As shown, the strain energy distribution concentration location of the integrated sealing disc-baffle structure optimization scheme of the turbine baffle assembly under emergency conditions is as follows: Figure 8 As shown, they are all concentrated at the first arc segment 7 and the straight segment 8 in the sealing plate 1 and the transition segment 2.

[0017] Comparing the clamping states of the turbine baffle assembly before and after optimization, the original design showed a clamping force of 0 N on the turbine blade-disk clamping end face 10 under emergency conditions, failing to meet the sealing requirements. In contrast, the optimized design achieved a clamping force of 11.4 kN on the turbine baffle on the turbine blade-disk clamping end face 10 under emergency conditions. This demonstrates that the assembly strain energy was released at a specific point under different operating conditions. Furthermore, the weight increase from the improvement was less than 1%, meeting the quality requirements.

[0018] Step 7: Baffle strength analysis; specifically including the following steps: Step 7.1: Based on the optimized turbine baffle configuration in Step 6 and the initial assembly parameters in Step 1, establish a finite element model of the turbine baffle assembly; Step 7.2: Perform strength verification.

[0019] The specific strength verification and design of the baffle are existing technologies and will not be elaborated here.

[0020] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for designing the clamping state of a turbine baffle assembly based on strain energy distribution optimization, characterized in that, Includes the following steps: Step 1: Obtain the initial assembly parameters of the turbine baffle assembly; Step 2: Obtain different operating conditions for the turbine baffle assembly; Step 3: Establish the finite element model of the turbine baffle assembly; Step 4: Obtain the assembly strain energy distribution of the turbine baffle using the finite element model from Step 3; Step 5: Based on the working conditions in Step 2 and using the finite element model in Step 3, obtain the assembly strain energy distribution of the turbine baffle under different working conditions. Step 6: Determine whether the assembly strain energy of the turbine baffle has been released at a fixed point under different operating conditions. If it has not been released at a fixed point, optimize the turbine baffle configuration while meeting the quality requirements, and repeat steps 3-6. If it has been released at a fixed point, proceed to the next step. Step 6 specifically includes the following steps: Step 6.1: Based on the assembly strain energy distribution of the turbine baffle in Step 4, determine the location of concentrated assembly strain energy; Step 6.2: Based on the distribution of assembly strain energy of the turbine baffle under different working conditions in Step 5, determine the location of concentrated assembly strain energy under different working conditions. Step 6.3: If the release location of the assembly strain energy under different operating conditions is not at the pressing end face of the turbine baffle against the turbine blade-disk, then optimize the turbine baffle configuration while meeting the quality requirements, and repeat steps 3-6; if the release location of the assembly strain energy under different operating conditions is at the pressing end face of the turbine baffle against the turbine blade-disk, then the fixed-point release of the assembly strain energy has been achieved, the optimization is complete, and proceed to the next step; optimizing the turbine baffle configuration includes the following: Based on the original turbine baffle configuration, a sealing tip is added; If a sealing tip already exists, change the length of the sealing tip; If the original turbine baffle configuration is an integrated sealing disc-baffle structure, the configuration of the transition section between the sealing disc and the turbine baffle is optimized based on the original turbine baffle configuration, including the tilt angle, the curvature of the transition section, the axial length and the radial thickness. Step 7: Strength analysis of the turbine baffle assembly.

2. The turbine baffle assembly clamping state design method based on strain energy distribution optimization according to claim 1, characterized in that, In step 1, the initial assembly parameters include the initial assembly preload and the initial interference fit of the cylindrical mating surface.

3. The turbine baffle assembly clamping state design method based on strain energy distribution optimization according to claim 1, characterized in that, In step 2, the operating conditions are determined by the turbine baffle assembly's designed operating speed, operating temperature distribution, and external load spectrum; different operating conditions include ground idle state, air idle state, hot weather takeoff state, and emergency state.

4. The turbine baffle assembly clamping state design method based on strain energy distribution optimization according to claim 1, characterized in that, Step 3 includes the following steps: Step 3.1: Obtain the 3D model of the turbine baffle assembly; Step 3.2: Based on the initial assembly parameters in Step 1, establish the finite element model of the turbine baffle assembly.

5. The turbine baffle assembly clamping state design method based on strain energy distribution optimization according to claim 1, characterized in that, In step 6.3, meeting the quality requirements means that, according to actual engineering needs, the weight increase of the turbine baffle assembly improvement does not exceed 1%.

6. The turbine baffle assembly clamping state design method based on strain energy distribution optimization according to claim 1, characterized in that, Step 7 includes the following steps: Step 7.1: Based on the optimized turbine baffle configuration in Step 6 and the initial assembly parameters in Step 1, establish a finite element model of the turbine baffle assembly; Step 7.2: Perform strength verification.

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