Methods, apparatus, electronic devices and storage media for determining the structure of hollow fan blades

Abstract

This application relates to a method, apparatus, electronic device, and storage medium for determining the structure of a hollow fan blade. The method involves acquiring stress distribution data, contour airfoil data, and a preset skin thickness for the fan blade to be designed. Based on the contour airfoil data and the preset skin thickness, a hollow design domain and skin structure are determined. Frequency-enhancing topology optimization is performed on the hollow design domain to obtain the target hollow structure. Based on blade vein biomimicry and stress distribution data, blade vein biomimicry design is performed on the target hollow structure to determine the target main vein structure and the target secondary vein structure. Based on the skin structure, the target main vein structure, and the target secondary vein structure, the target hollow blade structure of the fan blade to be designed is determined. This application optimizes the material distribution of the hollow fan blade, increasing the first-order natural frequency while satisfying structural reliability and manufacturability.

Description

Technical Field

[0001] This application relates to aero-engine technology, and more particularly to a method, apparatus, electronic device, and storage medium for determining the structure of hollow fan blades. Background Technology

[0002] In aero-engines, fan blades account for a significant proportion of the engine's weight, and lightweight fan blade design is crucial for achieving overall weight reduction and performance improvement in aero-engines. Hollow blade design is an effective way to achieve lightweight fan design.

[0003] In existing technologies, truss-core or coreless hollow blade structures are typically used to achieve lightweight design goals. However, these hollow blade structures cannot achieve optimal material distribution, have low material utilization, and face the problem of reduced first-order natural frequency, which may lead to aeroelastic instability risks and poor structural reliability. Summary of the Invention

[0004] This application provides a method, apparatus, electronic device, and storage medium for determining the structure of hollow fan blades, so as to optimize the material distribution of hollow fan blades and improve the first-order natural frequency while satisfying structural reliability and manufacturability.

[0005] In a first aspect, embodiments of this application provide a method for determining the structure of a hollow fan blade, the method comprising: Obtain stress distribution data, contour airfoil data, and preset skin thickness of the fan blades to be designed, and determine the hollow design domain and skin structure based on the contour airfoil data and preset skin thickness; Frequency-enhancing topology optimization is performed on the hollow design domain to obtain the target hollow structure. Based on leaf vein bionics and stress distribution data, the target hollow structure is designed using leaf vein bionics to determine the target main vein structure and the target secondary vein structure. Based on the skin structure, the target main vein structure, and the target secondary vein structure, the target hollow blade structure of the fan blade to be designed is determined.

[0006] Secondly, embodiments of this application also provide a hollow fan blade structure determination device, which includes: The hollow design domain and skin determination module is used to obtain stress distribution data, contour airfoil data and preset skin thickness of the fan blade to be designed, and to determine the design domain and skin structure based on the contour airfoil data and preset skin thickness. The design domain optimization module is used to perform topology optimization on the first-order natural frequencies within the hollow design domain to obtain the target hollow structure. The target hollow structure optimization module is used to perform blade vein biomimetic design on the target hollow structure based on blade vein biomimetic and stress distribution data, and to determine the target main vein structure and the target secondary vein structure. The target hollow blade structure determination module is used to determine the target hollow blade structure of the fan blade to be designed based on the skin structure, the target main vein structure, and the target secondary vein structure.

[0007] Thirdly, embodiments of this application also provide an electronic device, which includes: One or more processors; Storage device for storing one or more programs; When one or more programs are executed by one or more processors, the one or more processors implement any of the hollow fan blade structure determination methods provided in the embodiments of this application.

[0008] Fourthly, embodiments of this application also provide a storage medium including computer-executable instructions, which, when executed by a computer processor, are used to perform any of the hollow fan blade structure determination methods provided in embodiments of this application.

[0009] Fifthly, embodiments of this application also provide a computer program product, which includes a computer program that, when executed by a processor, implements any of the hollow fan blade structure determination methods provided in embodiments of this application.

[0010] This application obtains stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determines the design domain and skin structure based on the contour airfoil data and preset skin thickness. Frequency-enhancing topology optimization is performed on the hollow design domain to obtain the target hollow structure. By optimizing the frequency topology, the material distribution within the hollow blade design domain can be optimized, thereby increasing the first-order natural frequency of the structure. Based on blade vein bionics and stress distribution data, blade vein bionics design is performed on the target hollow structure to determine the target main vein structure and target secondary vein structure. Based on the main and secondary vein structures in blade vein bionics, and considering stress distribution data, the structural design within the target hollow structure can effectively improve the reliability of the subsequently determined target hollow blade structure. Based on the skin structure, target main vein structure, and target secondary vein structure, the target hollow blade structure of the fan blade to be designed is determined. Therefore, the technical solution of this application solves the problem that the hollow design of hollow fan blades cannot achieve optimal material distribution, has poor structural reliability, and faces the problem of reduced first-order natural frequency. It achieves the effect of optimizing the material distribution of hollow fan blades and improving the first-order natural frequency while satisfying structural reliability and manufacturability. Attached Figure Description

[0011] Figure 1a This is a flowchart of a method for determining the structure of a hollow fan blade according to Embodiment 1 of this application; Figure 1b This is a schematic diagram of a target hollow structure obtained after frequency boosting and topology optimization of the fan blades to be designed, as described in Embodiment 1 of this application. Figure 2a This is a flowchart of a method for determining the structure of a hollow fan blade according to Embodiment 2 of this application; Figure 2b This is a schematic diagram of the connecting support column of the cylindrical structure of a target main vein structure in Embodiment 2 of this application; Figure 2c This is a schematic diagram of the center line of a rib plate in Embodiment 2 of this application; Figure 2d This is a schematic diagram of a target hollow blade structure including a powder clearing channel structure in Embodiment 2 of this application; Figure 3a This is a flowchart of a method for determining the structure of a hollow fan blade according to Embodiment 3 of this application; Figure 3b This is a schematic diagram of a target hollow structure within a hollow design domain, as shown in Embodiment 3 of this application; Figure 3c This is a schematic diagram of a target main vein structure in Embodiment 3 of this application; Figure 4 This is a schematic diagram of a hollow fan blade structure determination device according to Embodiment 4 of this application; Figure 5 This is a schematic diagram of the structure of an electronic device according to Embodiment 5 of this application. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0013] It should be noted that the terms "first" and "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0014] Example 1 Figure 1a This is a flowchart of a method for determining the structure of a hollow fan blade provided in Embodiment 1 of this application. This embodiment can be applied to the case of lightweight design of fan blades for aero engines. The method can be executed by a hollow fan blade structure determination device, which can be implemented in software and / or hardware and specifically configured in an aero engine design platform.

[0015] See Figure 1a The method for determining the hollow fan blade structure shown includes the following steps: S110. Obtain the stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determine the hollow design domain and skin structure based on the contour airfoil data and preset skin thickness.

[0016] The fan blade to be designed can be a solid fan blade in an aero-engine that requires lightweight design. Stress distribution data can be the stress distribution characteristics of the fan blade under operating load. For example, stress distribution data can be obtained through software analysis or relevant parameter design specifications, etc., and this application does not specifically limit this. Equal-height airfoil data can be the outline data of each equal-height section of the fan blade to be designed, used to determine the hollow design domain and skin structure. For example, equal-height airfoil data can be obtained through software analysis or relevant parameter design specifications, etc., and this application does not specifically limit this. Preset skin thickness can be a pre-set thickness of the skin of the fan blade to be designed, used to determine the skin structure. Hollow design domain can be the area of ​​the fan blade to be designed where a hollow structure is designed. Skin structure can be the structure of the skin area of ​​the fan blade to be designed.

[0017] Import the airfoil data of each contour surface of the fan blade to be designed into the 3D modeling software. Use the spline curve function to connect the airfoil data points of each contour surface to generate a smooth airfoil curve, and sweep along the guide line in the direction of blade height to construct a 3D geometric model of the solid fan blade.

[0018] In one alternative embodiment, after constructing a three-dimensional geometric model of a solid fan blade, the solid fan blade model can be modally analyzed and its strength calculated using the finite element analysis software ANSYS (a technical term, a software name) to obtain key performance data such as its first natural frequency, mode shape, and stress distribution, which can then be used as a benchmark for subsequent design and verification.

[0019] In the modeling software, the contour lines of each section in the acquired contour surface airfoil data are offset inwards, with the offset distance being the preset skin thickness. The offset contour lines are then swept along the same guide line to determine the hollow design domain that conforms to the shape. Optionally, to reduce the risk of stress concentration during subsequent manufacturing and use, all edges of this hollow design domain need to be rounded.

[0020] By using Boolean operations, the solid blade model is subtracted from the hollow solid model. After the operation, the solid blade model is "hollowed out," leaving only the uniformly thick outer shell, which forms the skin structure that constitutes the aerodynamic profile of the blade.

[0021] S120. Perform frequency boosting topology optimization on the hollow design domain to obtain the target hollow structure.

[0022] The target hollow structure can be the structure obtained after topology optimization of the hollow design domain, maximizing the first-order natural frequency of the blade. For example, a topology optimization finite element model can be established using the hollow design domain as the design domain and the skin structure as the non-design domain. Based on the set optimization objectives and constraints, topology optimization of the hollow design domain can be performed using ANSYS software, ultimately obtaining the target hollow structure under given constraints. For example, maximizing the first-order natural modal frequency of the blade can be the optimization objective, resulting in a target hollow structure that maximizes the first-order frequency while achieving optimal material distribution within the cavity. Figure 1b This is a schematic diagram of the target hollow structure obtained after frequency boosting and topology optimization of a fan blade to be designed.

[0023] S130. Based on the bionic design of blade veins and stress distribution data, the target hollow structure is designed using the bionic design of blade veins to determine the target main vein structure and the target secondary vein structure.

[0024] Leaf vein biomimicry can be used to determine the target main vein structure and target secondary vein structure based on the veins of plant leaves. Biomimetic design provides a wealth of inspiration for lightweight structures. However, the current application of this concept in leaf design is mostly limited to introducing simple honeycomb or regular grid structures, failing to fully learn from and transform the more sophisticated and efficient structures that have evolved over millions of years in nature. For example, the hierarchical vein system of "main vein-secondary vein" commonly found in plant leaves demonstrates an excellent strategy for balancing lightweight and mechanical performance: the robust main vein acts as the core "main beam" to bear and transmit the main load, while the dense secondary veins form a multi-path and networked support system, effectively dispersing stress and significantly improving local stiffness, thereby achieving excellent overall structural performance with minimal material consumption.

[0025] The target main vein structure can be a main vein structure designed based on leaf vein biomimicry. The target secondary vein structure can be a secondary vein structure designed based on leaf vein biomimicry. Based on leaf vein biomimicry, the target main vein structure can be determined by designing the main vein in the target hollow structure, and the target secondary vein structure can be determined by designing the secondary vein in the target hollow structure based on stress distribution data.

[0026] The centerline representing the main load transfer path can be obtained through threshold segmentation, morphological processing, and skeleton extraction. Based on path length, connectivity, and branching characteristics, and combined with material distribution density or stress distribution weights, the skeleton is screened and smoothed through parametric curve fitting. Based on the smooth centerline, a preset cross-section is constructed and cross-section sweeping or variable cross-section lofting operations are performed along its path to reconstruct it into a solid structure with continuous geometric shape, thus forming a biomimetic "main vein" structure, i.e., the target main vein structure. The target main vein structure is located in the lower middle part of the hollow design domain of the blade, with a cavity region in the middle. The walls of the blade basin and the back side of the cavity region are connected by multiple connecting struts.

[0027] In the hollow design domain above the target main vein structure, the material in the topology optimization results is discretely distributed. Combining the first-order mode displacement cloud map of the solid blade model and the discrete material distribution trend in this region, a leaf vein-shaped rib is added to the hollow design domain above the target main vein structure as a biomimetic "secondary vein" structure, that is, the target secondary vein structure. The extension direction of the rib is from the low amplitude region to the high amplitude region, and it is connected to the blade base and the blade back.

[0028] S140. Based on the skin structure, target main vein structure, and target secondary vein structure, determine the target hollow blade structure of the fan blade to be designed.

[0029] By merging the skin structure, the target main vein structure, and the target secondary vein structure using Boolean syntax, a complete three-dimensional model of the hollow fan blade with vein-inspired design is formed, i.e., the target hollow blade structure. Advances in advanced manufacturing technologies have made it possible to design more complex and refined hollow fan blade structures. For example, the manufacturing technology for hollow fan blade structures can employ a superplastic forming / diffusion bonding combination process or additive manufacturing. The prototyping process for the target hollow blade structure is not limited to additive manufacturing or superplastic forming / diffusion bonding combinations.

[0030] It should be noted that all information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data used for analysis, etc.) involved in this disclosure are information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data comply with the relevant laws, regulations and standards of the relevant regions.

[0031] Among the key performance indicators of aero-engines, the thrust-to-weight ratio directly determines the flight efficiency, payload capacity, and economy of an aircraft, and lightweight design is the core approach to improving it. As one of the largest and most numerous rotating components in an engine, the fan blades account for a significant proportion of the overall engine weight. Therefore, effectively reducing the weight of the fan blades is of decisive significance for achieving overall weight reduction and performance leap in aero-engines.

[0032] Currently, hollow blade design has become the mainstream technology for lightweight blades and is widely used in engineering practice. Many advanced turbofan engines employ wide-chord hollow fan blades. However, existing mainstream hollow blade designs have certain limitations: their internal structure often fails to achieve optimal material distribution, resulting in low material utilization; simultaneously, while significantly reducing weight, these designs frequently face the problem of a decrease in the first-order natural frequency, thereby increasing the risk of resonance or aeroelastic instability under complex aerodynamic loads. Therefore, there is an urgent need to develop more advanced lightweight design methods to synergistically achieve significant weight reduction and superior mechanical properties.

[0033] Topology optimization is a structural optimization design method that optimizes material distribution to achieve a more efficient load-bearing structure during the structural conceptual design stage, but its application in hollow blades is limited. Furthermore, biomimetic design provides a wealth of inspiration for structural lightweighting. However, current applications of this concept in blade design are mostly limited to introducing simple honeycomb or regular grid structures, failing to fully learn from and transform the more sophisticated and efficient structures that have evolved over millions of years in nature. For example, the hierarchical venation system of "main vein-secondary vein" commonly found in plant leaves demonstrates an excellent strategy for balancing lightweighting and mechanical performance: the robust main vein acts as the core "main beam" to bear and transmit the main load, while the dense secondary veins form a multi-path, networked support system, effectively dispersing stress and significantly improving local stiffness, thus achieving excellent overall structural performance with minimal material consumption.

[0034] The technical solution of this embodiment obtains stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determines the design domain and skin structure based on the contour airfoil data and preset skin thickness; performs frequency-enhancing topology optimization on the hollow design domain to obtain the target hollow structure. By performing topology optimization on the frequency, the material distribution within the hollow blade design domain can be optimized, thereby increasing the first-order natural frequency of the structure; based on blade vein bionics and stress distribution data, performs blade vein bionics design on the target hollow structure to determine the target main vein structure and the target secondary vein structure. Based on the main vein and secondary vein structures in blade vein bionics, and considering the stress distribution data, the structural design within the target hollow structure can effectively improve the reliability of the subsequently determined target hollow blade structure; and determines the target hollow blade structure of the fan blade to be designed based on the skin structure, the target main vein structure, and the target secondary vein structure. Therefore, the technical solution of this application solves the problem that the hollow design of hollow fan blades cannot achieve optimal material distribution, has poor structural reliability, and faces the problem of reduced first-order natural frequency. It achieves the effect of optimizing the material distribution of hollow fan blades and improving the first-order natural frequency while satisfying structural reliability and manufacturability.

[0035] Example 2 Figure 2a This is a flowchart of a method for determining the structure of a hollow fan blade provided in Embodiment 2 of this application. The technical solution of this embodiment is further refined based on the above technical solution.

[0036] Furthermore, the phrase "based on blade vein bionics and stress distribution data, design the target hollow structure using blade vein bionics to determine the target main vein structure and target secondary vein structure" is refined to: "Based on stress distribution data and density field data of the target hollow structure, perform reverse modeling of the target hollow structure through geometric reconstruction and geometric enhancement to obtain the target main vein structure; based on the secondary veins in blade vein bionics, design the secondary veins in the non-target main vein structure regions of the target hollow structure to obtain the target secondary vein structure," thereby optimizing the target hollow structure based on blade vein bionics.

[0037] See Figure 2a The method for determining the structure of a hollow fan blade, as shown, includes: S210. Obtain the stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determine the hollow design domain and skin structure based on the contour airfoil data and preset skin thickness.

[0038] S220. Perform frequency boosting topology optimization on the hollow design domain to obtain the target hollow structure.

[0039] S230. Based on the stress distribution data and the density field data of the target hollow structure, the target hollow structure is reverse-modeled through geometric reconstruction and geometric enhancement to obtain the target main vein structure.

[0040] Density field data can be the density field data of the material distribution of the target hollow structure, used for inverse modeling of the target hollow structure. Density field data can be obtained after topology optimization of the hollow design domain. Geometric reconstruction can involve determining the centerline representing the main load transfer path through morphological processing, reconstructing it into a solid structure with a continuous geometric shape, thus forming a biomimetic "main vein" structure, used to obtain the target main vein structure. Geometric enhancement can involve geometrically enhancing the stress concentration locations of the target hollow structure using stress distribution data, used to obtain the target main vein structure. For example, inverse modeling of the target hollow structure can involve geometrically reconstructing the target hollow structure based on density field data, and then geometrically enhancing the geometric coincidence result based on stress distribution data to obtain the target main vein structure.

[0041] In one optional embodiment, based on stress distribution data and density field data of the target hollow structure, the target hollow structure is reverse-modeled through geometric reconstruction and geometric enhancement to obtain the target main vein structure. This includes: threshold segmentation of the target hollow structure based on a preset density threshold and density field data of the target hollow structure to obtain a material concentration region; morphological processing of the material concentration region to obtain the main vein region; skeleton extraction and geometric reconstruction of the main vein region to obtain an initial main vein structure; and geometric enhancement of the initial main vein structure based on stress distribution data to obtain the target main vein structure.

[0042] The preset density threshold can be a pre-defined threshold for threshold segmentation of the density field. For example, the preset density threshold can be determined by a professional technician based on experimentation or experience; this application does not impose specific limitations on this. The material concentration region can be the area in the target hollow structure where the material distribution density is greater than the preset density threshold, used to obtain the main vein region. Threshold segmentation processing is performed on the density field data according to the preset density threshold, converting the continuous density distribution into a binary material region, and the material concentration region is extracted based on the preset density threshold.

[0043] Morphological processing is a method in image processing used to remove isolated noise points and enhance structural connectivity. For example, morphological processing may include opening and closing operations. The main vein region can be a continuous material distribution region within a material concentration area, used to obtain the initial main vein structure.

[0044] Skeleton extraction is an image processing method used to extract the skeletal structure of a subject to obtain an initial main vein structure. Skeleton extraction of the main vein region yields a spatial skeleton structure representing the central location of material distribution. Optionally, after skeleton extraction, the skeleton can be further filtered based on path length, connectivity, and branching features to extract the dominant load-bearing path running from the leaf root to the middle of the leaf, serving as the centerline of the biomimetic "main vein" structure.

[0045] After skeleton extraction, the results are geometrically reconstructed to obtain the initial main vein structure. This initial main vein structure can be the initial result of the biomimetic "main vein" obtained after sequentially extracting the skeleton and geometrically reconstructing the main vein region. For example, geometric reconstruction of the skeleton extraction results can involve parametric curve fitting and smoothing, followed by cross-sectional sweeping or variable cross-section lofting operations based on a smooth centerline, reconstructing it into a solid structure with a continuous geometric shape. This solid structure is mainly distributed in the lower part of the hollow design domain of the blade. For example, parametric curve fitting can use spline curves or NURBS curves to achieve continuous representation.

[0046] Optionally, geometric reinforcement of the initial main vein structure can be achieved by increasing material distribution at the leading and trailing edges of the target hollow structure leaf root to perform local geometric reinforcement.

[0047] Based on the stress distribution characteristics of the blade under working load, the initial main vein structure is locally geometrically reinforced at high stress concentration areas such as the leading and trailing edges in the blade root region. For example, the geometric reinforcement can be achieved by increasing the local material thickness or expanding the cross-sectional dimensions to reduce the stress concentration and improve the structural durability, thereby obtaining the target main vein structure.

[0048] The target main vein structure can be connected to the inner wall of the blade skin structure via multiple connecting struts distributed along the spanwise direction. For example, the connecting struts can be cylindrical structures to ensure effective load transfer between the main vein structure and the blade base and abaxial surface. After the connecting struts are parameterized as cylinders, the stiffness and weight of the structure can be optimized by adjusting the diameter and number of cylinders. Finally, the optimal cylindrical support distribution structure is selected by analyzing the parameter influence mechanism. Figure 2b This is a schematic diagram of the connecting support of a cylindrical structure for a target main vein structure.

[0049] By threshold segmenting the target hollow structure based on a preset density threshold and density field data, a material concentration region is obtained. This material concentration region is the main load region. Determining the target main vein structure within this region allows it to bear and transmit the main load. Morphological processing is then performed on the material concentration region to obtain the main vein region. Skeleton extraction and geometric reconstruction are then performed on the main vein region to obtain the initial main vein structure. Based on stress distribution data, the initial main vein structure is geometrically reinforced to obtain the target main vein structure. Through morphological processing, skeleton extraction, and geometric reconstruction, a continuous and smooth initial main vein structure is obtained, optimizing the material distribution. Finally, geometric reinforcement of the initial main vein structure is performed using stress distribution data to reduce stress concentration and improve structural durability, thereby enhancing the reliability of the target main vein structure.

[0050] S240. Based on the secondary veins in leaf vein bionics, secondary veins are designed for the non-target main vein structure region in the target hollow structure to obtain the target secondary vein structure.

[0051] Secondary veins are the multi-path and networked support system of leaf veins in leaf vein biomimetics. Designing secondary veins in the non-target main vein structural areas of the target hollow structure can effectively disperse stress and significantly improve local stiffness, thereby achieving excellent overall structural performance with minimal material consumption. For example, the target secondary vein structure can be a leaf vein-inspired rib. For example, the target secondary vein structure can take the form of one of the following: radiating parallel veins, bifurcated veins, or palmate network veins.

[0052] In one optional embodiment, based on the secondary veins in leaf vein bionics, secondary vein design is performed on the non-target main vein structure region in the target hollow structure to obtain the target secondary vein structure, including: based on the radiating parallel vein structure of the secondary veins in leaf vein bionics, secondary vein design is performed on the non-target main vein structure region in the target hollow structure to obtain the target secondary vein structure connecting the target main vein structure and the skin structure.

[0053] In the target hollow structure region above the target main vein structure, the topology optimization results show a discretized and fragmented material distribution. Secondary vein design aims to transform this discretization trend into a manufacturable reinforced structure. Specifically, secondary vein design can involve combining the obtained first-order modal displacement cloud map of the solid blade with the discrete material distribution in that region, and designing ribs that mimic the secondary veins of a leaf to form a "secondary vein" structure, i.e., the target secondary vein structure.

[0054] The first-order mode displacement cloud map and the discrete material distribution in the region can be obtained by importing the airfoil data of each contour surface of the fan blade to be designed into a three-dimensional modeling software to construct a three-dimensional geometric model of the solid fan blade, and then performing modal analysis and strength calculation on the solid fan blade model.

[0055] Discrete material distribution often exhibits irregular, tentacle-like trend lines. Based on the radiating parallel vein structure of secondary veins in blade biomimicry, multiple rib centerlines are designed extending in roughly opposite directions, using these tentacle-like trend lines as a foundation. These centerlines converge at a point on the main vein structure, while simultaneously determining the approximate span angle range of the rib centerlines. Starting from this point, several rib centerlines are set within the defined span angle range, and the ribs are drawn using these centerlines as a reference. In the spanwise direction, one end of the rib connects to the target main vein structure, while the other end and its chordally aligned side connect to the inner wall surface of the blade skin structure. For example... Figure 2c This is a schematic diagram of the centerline of a rib. Figure 2c The dashed line is the bisector of the span angle, the solid line is the center line of the rib, and the angle between the center lines of the two outermost ribs is the span angle.

[0056] Optionally, the thickness of the ribs gradually decreases from the connection point with the target main vein structure to the connection point with the skin structure; the ribs are parameterized using the rib root thickness, rib top thickness, number of ribs, and span angle as parameters; the optimal rib distribution structure is determined by analyzing the influence mechanism of the rib parameters. The analysis of the influence mechanism of the rib parameters includes the stiffness influence mechanism and the weight influence mechanism.

[0057] The thickness of the injected parallel vein structure is designed in a gradient form, gradually thinning from the connection root with the target main vein structure to the connection top with the skin structure to optimize weight distribution. The specific geometric parameters of the ribs can be parametrically modeled and optimized. For example, geometric parameters may include rib root thickness, rib top thickness, number of ribs, and span angle.

[0058] By analyzing the influence mechanism of rib parameters on stiffness and weight, the optimal rib distribution structure is determined. For example, the specific geometric parameters of the ribs can be a root thickness of 3 mm (millimeters, a unit of length), a top thickness of 1 mm, a total of 7 ribs, and a span angle of 75 degrees.

[0059] Preferably, the design process should consider the adaptability to manufacturing processes. For example, for additive manufacturing processes, the minimum feature size of the rib structure should not be less than the minimum forming size of additive manufacturing (not less than 0.6 mm); the overhang angle of the internal structure should meet the requirements of additive manufacturing processes (not less than 45 degrees); and the edges of the structure should be rounded to reduce stress concentration.

[0060] By designing a secondary vein structure based on the secondary vein biomimetic of blade veins, a secondary vein structure is created for the non-target main vein structure region in the target hollow structure. This results in a target secondary vein structure that connects the target main vein structure and the skin structure. This increases the effective stress dispersion of the target secondary vein structure and significantly improves the local stiffness, thereby achieving excellent overall structural performance with minimal material consumption.

[0061] In one optional embodiment, after designing secondary veins in the non-target main vein structure region of the target hollow structure based on secondary vein biomimicry to obtain the target secondary vein structure, the method further includes: adding a powder clearing channel structure facing the target main vein structure between two adjacent target secondary vein structures.

[0062] The powder cleaning channel structure can be designed to meet the requirements of additive manufacturing processes, serving as a channel for powder cleaning. For example... Figure 2d This is a schematic diagram of a target hollow blade structure including a powder-cleaning channel. Figure 2dIn diagram 2d, 1 represents the blade skin structure, 2 represents the target main vein structure, 3 represents the ribs in the target secondary vein structure, 4 represents the supporting cylinder within the target main vein structure, 5 represents the closed cavity between the ribs, and 6 represents the powder removal channel structure. As can be observed in diagram 2d, the adjacent ribs form a closed cavity with the main vein structure 2. Therefore, the powder removal channel structure 6 needs to be added to facilitate the smooth discharge of metal powder after manufacturing.

[0063] At the lowest point of the root of the closed cavity 5 formed between every two adjacent ribs 3, facing the leaf root, a powder removal channel 6 is designed. This channel 6 connects the closed cavity 5 with the larger cavity area where the target main vein structure 2 is located below. The cross-sectional shape of the powder removal channel structure can be designed as a funnel shape that gradually narrows from the closed cavity to the target main vein structure, so that the metal powder can be smoothly discharged after manufacturing.

[0064] By adding a powder clearing channel structure facing the target main vein structure between two adjacent target secondary vein structures, and taking into account the requirements of additive manufacturing process, it is possible to facilitate the smooth discharge of metal powder after manufacturing.

[0065] S250. Based on the skin structure, target main vein structure, and target secondary vein structure, determine the target hollow blade structure of the fan blade to be designed.

[0066] The technical solution of this embodiment reverse models the target hollow structure based on stress distribution data and density field data of the target hollow structure through geometric reconstruction and geometric enhancement to obtain the target main vein structure. Considering the stress distribution data and density field data of the target hollow structure, the target main vein structure can serve as the core "main beam" to bear and transmit the main load. Based on the secondary veins in blade vein bionics, secondary vein design is performed on the non-target main vein structure areas in the target hollow structure to obtain the target secondary vein structure. The target secondary vein structure forms a multi-path and networked support system in imitation of the secondary veins in blade vein bionics, which effectively disperses stress and significantly improves local stiffness, thereby improving the reliability of the subsequently determined target hollow blade structure.

[0067] Example 3 Figure 3a This is a flowchart of a method for determining the structure of a hollow fan blade provided in Embodiment 3 of this application. The technical solution of this embodiment is further refined based on the above technical solution.

[0068] Furthermore, the phrase "to perform frequency-enhancing topology optimization on the hollow design domain to obtain the target hollow structure" is refined to: "Within the hollow design domain, topology optimization is performed on the finite element model to maximize the first-order natural mode frequency of the blade as the optimization objective, and the weight reduction rate is not lower than the preset weight reduction threshold as the constraint condition, to obtain the target hollow structure." The target hollow structure is obtained through topology optimization.

[0069] See Figure 3a The method for determining the structure of a hollow fan blade, as shown, includes: S310. Obtain the stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determine the hollow design domain and skin structure based on the contour airfoil data and preset skin thickness.

[0070] S320. Within the hollow design domain, topology optimization finite element model is used to maximize the first-order natural mode frequency of the blade as the optimization objective and the weight reduction rate is not lower than the preset weight reduction threshold as the constraint condition to perform topology optimization and obtain the target hollow structure.

[0071] Topology optimization finite element models can use mathematical algorithms to find the optimal material distribution within a given design space, and can be used to optimize the design of a hollow design domain to obtain the target hollow structure. The preset weight reduction threshold can be a pre-defined minimum weight reduction value. For example, the preset weight reduction threshold can be determined by professional technicians based on experience or set according to preset design requirements; this application does not specifically limit this.

[0072] A topology optimization finite element model is established, using the hollow design domain as the design domain and the skin structure as the non-design domain. Topology optimization is performed with the goal of maximizing the first-order natural modal frequency of the blades and the constraint that the weight reduction rate is not lower than a preset weight reduction threshold. For example, topology optimization can be performed using ANSYS software. After topology optimization, the optimal material distribution diagram of the hollow design domain, which maximizes the first-order frequency under given constraints, is obtained; this is the target hollow structure. Figure 3b This is a schematic diagram of a target hollow structure within a hollow design domain. (Example) Figure 3c This is a schematic diagram of a target main vein structure.

[0073] S330. Based on blade vein bionics and stress distribution data, the target hollow structure is designed using blade vein bionics to determine the target main vein structure and the target secondary vein structure.

[0074] S340. Based on the skin structure, target main vein structure, and target secondary vein structure, determine the target hollow blade structure of the fan blade to be designed.

[0075] The technical solution of this embodiment is to perform topology optimization within the hollow design domain, with the optimization objective being to maximize the first-order natural modal frequency of the blade and the constraint that the weight reduction rate is not lower than a preset weight reduction threshold, to obtain the target hollow structure and improve the first-order natural modal frequency of the target hollow structure.

[0076] Example 4 Figure 4The diagram shown is a schematic representation of a hollow fan blade structure determination device according to Embodiment 4 of this application. This embodiment is applicable to the lightweight design of fan blades for aero engines. The specific structure of the hollow fan blade structure determination device is as follows: The hollow design domain and skin determination module 410 is used to acquire stress distribution data, contour airfoil data and preset skin thickness of the fan blade to be designed, and to determine the hollow design domain and skin structure based on the contour airfoil data and preset skin thickness. Hollow design domain optimization module 420 is used to perform frequency-enhancing topology optimization on the hollow design domain to obtain the target hollow structure; The target hollow structure optimization module 430 is used to perform blade vein biomimetic design on the target hollow structure based on blade vein biomimetic and stress distribution data, and to determine the target main vein structure and the target secondary vein structure. The target hollow blade structure determination module 440 is used to determine the target hollow blade structure of the fan blade to be designed based on the skin structure, the target main vein structure, and the target secondary vein structure.

[0077] The technical solution of this embodiment obtains stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determines the design domain and skin structure based on the contour airfoil data and preset skin thickness; performs frequency-enhancing topology optimization on the hollow design domain to obtain the target hollow structure. By performing topology optimization on the frequency, the material distribution within the hollow blade design domain can be optimized, thereby increasing the first-order natural frequency of the structure; based on blade vein bionics and stress distribution data, performs blade vein bionics design on the target hollow structure to determine the target main vein structure and the target secondary vein structure. Based on the main vein and secondary vein structures in blade vein bionics, and considering the stress distribution data, the structural design within the target hollow structure can effectively improve the reliability of the subsequently determined target hollow blade structure; and determines the target hollow blade structure of the fan blade to be designed based on the skin structure, the target main vein structure, and the target secondary vein structure. Therefore, the technical solution of this application solves the problem that the hollow design of hollow fan blades cannot achieve optimal material distribution, has poor structural reliability, and faces the problem of reduced first-order natural frequency. It achieves the effect of optimizing the material distribution of hollow fan blades and improving the first-order natural frequency while satisfying structural reliability and manufacturability.

[0078] Optionally, the target hollow structure optimization module 430 includes: The target main vein structure determination unit is used to reverse model the target hollow structure through geometric reconstruction and geometric enhancement based on stress distribution data and density field data of the target hollow structure to obtain the target main vein structure; The target secondary vein structure determination unit is used to design secondary veins in the non-target main vein structure region of the target hollow structure based on the secondary veins in leaf vein bionics, so as to obtain the target secondary vein structure.

[0079] Optionally, the target main structure determination unit includes: The material concentration region is used to obtain sub-units, which are used to perform threshold segmentation of the target hollow structure based on a preset density threshold and the density field data of the target hollow structure to obtain the material concentration region; The main vein region is divided into sub-units, which are used to perform morphological processing on the concentrated material region to obtain the main vein region; The initial main vein structure is used to obtain sub-units, which are used to extract the skeleton and reconstruct the geometry of the main vein region to obtain the initial main vein structure. The target main vein structure is used to obtain sub-units, which are used to geometrically enhance the initial main vein structure based on stress distribution data, thus obtaining the target main vein structure.

[0080] Optionally, the target secondary vein structure determination unit includes: The target secondary vein structure yields sub-units, which are used to design secondary vein structures based on secondary vein biomimicry in leaf veins. These sub-units are then used to design secondary vein structures in the non-target main vein structure region of the target hollow structure, resulting in the target secondary vein structure that connects the target main vein structure and the skin structure.

[0081] Optionally, the target hollow structure optimization module 430 also includes: The powder clearing channel structure adds a unit for adding a powder clearing channel structure facing the target main vein structure between two adjacent target secondary vein structures.

[0082] Optional, the hollow design domain optimization module 420 includes: The target hollow structure is obtained as a unit, which is used to perform topology optimization within the hollow design domain through a finite element model. The optimization objective is to maximize the first-order natural modal frequency of the blade, and the constraint is that the weight reduction rate is not lower than a preset weight reduction threshold. The target hollow structure is then obtained.

[0083] The fan blade structure determination device provided in this application embodiment can execute the fan blade structure determination method provided in any embodiment of this application, and has the corresponding functional modules and beneficial effects for executing the fan blade structure determination method.

[0084] According to embodiments of the present invention, the present invention also provides an electronic device, a readable storage medium, and a computer program product.

[0085] Example 5 Figure 5 This is a schematic diagram of the structure of an electronic device provided in Embodiment 5 of this application, as shown below. Figure 5As shown, the electronic device includes a processor 510, a memory 520, an input device 530, and an output device 540; the number of processors 510 in the electronic device can be one or more. Figure 5 Taking a processor 510 as an example; the processor 510, memory 520, input device 530, and output device 540 in the electronic device can be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0086] The memory 520, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the hollow fan blade structure determination method in this embodiment (e.g., hollow design domain and skin determination module 410, hollow design domain optimization module 420, target hollow structure optimization module 430, and target hollow blade structure determination module 440). The processor 510 executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory 520, thereby implementing the aforementioned fan blade structure determination method.

[0087] The memory 520 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory 520 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 520 may further include memory remotely located relative to the processor 510, which can be connected to the electronic device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0088] Input device 530 can be used to receive input character information and generate key signal inputs related to user settings and function control of the electronic device. Output device 540 may include display devices such as a display screen.

[0089] Example 6 Embodiment Six of this application also provides a storage medium containing computer-executable instructions. When executed by a computer processor, the computer-executable instructions are used to perform a method for determining the structure of a hollow fan blade. The method includes: acquiring stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed; determining a hollow design domain and skin structure based on the contour airfoil data and preset skin thickness; performing frequency-boosting topology optimization on the hollow design domain to obtain a target hollow structure; performing blade vein biomimetic design on the target hollow structure based on blade vein biomimetic and stress distribution data to determine the target main vein structure and target secondary vein structure; and determining the target hollow blade structure of the fan blade to be designed based on the skin structure, the target main vein structure, and the target secondary vein structure.

[0090] Of course, the computer-executable instructions provided in the embodiments of this application are not limited to the method operations described above, but can also perform related operations in the hollow fan blade structure determination method provided in any embodiment of this application.

[0091] Based on the above description of the implementation methods, those skilled in the art can clearly understand that this application can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0092] It is worth noting that in the embodiments of the hollow fan blade structure determination device described above, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of this application.

[0093] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for determining the structure of hollow fan blades, characterized in that, include: Obtain stress distribution data, contour airfoil data, and preset skin thickness of the fan blade to be designed, and determine the hollow design domain and skin structure based on the contour airfoil data and the preset skin thickness; Frequency-boosting topology optimization is performed on the hollow design domain to obtain the target hollow structure; Based on the bionic design of blade veins and the stress distribution data, the target hollow structure is designed using the bionic design of blade veins to determine the target main vein structure and the target secondary vein structure. Based on the skin structure, the target main vein structure, and the target secondary vein structure, the target hollow blade structure of the fan blade to be designed is determined.

2. The method according to claim 1, characterized in that, Based on blade venation biomimicry and the stress distribution data, a blade venation biomimicry design is performed on the target hollow structure to determine the target main vein structure and the target secondary vein structure, including: Based on the stress distribution data and the density field data of the target hollow structure, the target hollow structure is reverse-modeled through geometric reconstruction and geometric enhancement to obtain the target main vein structure; Based on the secondary veins in leaf vein bionics, secondary veins are designed for the non-target main vein structure region in the target hollow structure to obtain the target secondary vein structure.

3. The method according to claim 2, characterized in that, The process involves reverse modeling the target hollow structure based on the stress distribution data and the density field data of the target hollow structure, through geometric reconstruction and geometric enhancement, to obtain the target main vein structure, including: The target hollow structure is segmented based on a preset density threshold and the density field data of the target hollow structure to obtain a material concentration region; Morphological processing is performed on the concentrated area of ​​the material to obtain the main vein region; The skeleton of the main vein region is extracted and geometrically reconstructed to obtain the initial main vein structure. Based on the stress distribution data, the initial main vein structure is geometrically enhanced to obtain the target main vein structure.

4. The method according to claim 2, characterized in that, The secondary vein design, based on the biomimetic principles of leaf veins, involves designing secondary veins in the non-target main vein structure region of the target hollow structure to obtain the target secondary vein structure, including: Based on the secondary vein ejection parallel vein structure in leaf vein bionics, secondary vein design is performed on the non-target main vein structure region in the target hollow structure to obtain the target secondary vein structure connecting the target main vein structure and the skin structure.

5. The method according to claim 2, characterized in that, In the secondary vein design based on leaf vein biomimicry, after designing secondary vein structures in the non-target main vein area of ​​the target hollow structure to obtain the target secondary vein structure, the method further includes: A powder clearing channel structure is added between two adjacent target secondary vein structures, facing the target main vein structure.

6. The method according to claim 1, characterized in that, The step of performing frequency-boosting topology optimization on the hollow design domain to obtain the target hollow structure includes: Within the hollow design domain, a topology optimization finite element model is used to maximize the first-order natural mode frequency of the blade as the optimization objective and to obtain the target hollow structure by ensuring that the weight reduction rate is not lower than a preset weight reduction threshold.

7. A device for determining the structure of hollow fan blades, characterized in that, include: The hollow design domain and skin determination module is used to acquire stress distribution data, contour airfoil data and preset skin thickness of the fan blade to be designed, and to determine the design domain and skin structure based on the contour airfoil data and the preset skin thickness. The hollow design domain optimization module is used to perform frequency-enhancing topology optimization on the hollow design domain to obtain the target hollow structure. The target hollow structure optimization module is used to perform blade vein bionic design on the target hollow structure based on blade vein bionics and the stress distribution data, and to determine the target main vein structure and the target secondary vein structure. The target hollow blade structure determination module is used to determine the target hollow blade structure of the fan blade to be designed based on the skin structure, the target main vein structure, and the target secondary vein structure.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the hollow fan blade structure determination method as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the hollow fan blade structure determination method as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method for determining the hollow fan blade structure as described in any one of claims 1-6.

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