Ram air turbine disc parametric modeling and structure automatic optimization method

Abstract

The invention provides a ram air turbine disc parametric modeling and structure automatic optimization method, which comprises the following steps of: establishing a three-dimensional model of a ram air turbine disc, and establishing a strength optimization mathematical model of the ram air turbine disc, performing ram air turbine disc parameter optimization through the ram air turbine disc strength optimization mathematical model on the basis of a particle swarm optimization algorithm, performing assignment on the three-dimensional model of the ram air turbine disc on the basis of the optimized parameters to obtain the three-dimensional model of the ram air turbine disc for analysis, and performing heat transfer-strength coupling analysis on the three-dimensional model of the ram air turbine disc to obtain a heat transfer-strength coupling analysis result. The turbine disc stress and the turbine disc quality are obtained, the obtained turbine disc stress and the turbine disc quality are evaluated, whether the obtained turbine disc stress and the obtained turbine disc quality reach the optimization target or not is judged, if yes, optimization is ended, and if not, optimization operation continues. According to the method, parametric modeling and automatic structure optimization of the ram air turbine disc can be achieved, and design of the ram air turbine disc is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of impeller machinery, and in particular to a method for parameterized modeling and automatic structural optimization of a ram air turbine disk. Background Art

[0002] In the current pre-research plan, the maximum design speed of the aircraft is 4 to 6 Mach; while the maximum flight speed of traditional turbojet engines or small bypass ratio turbofan engines is difficult to exceed 3 Mach, so the turbine-ramjet combined cycle has become the current mainstream solution for hypersonic propulsion.

[0003] At high Mach numbers, the aircraft flies in ramjet mode, only the ramjet engine components work, and its turbine-based components basically stop working. The shaft power output provided by the turbine-based rotating components to the electromechanical system is reduced or disappears, making it difficult to maintain the shaft power requirements of the aircraft and its onboard equipment. Therefore, using the high-speed incoming flow of the aircraft during high-speed flight to drive the air turbine to expand and do work, and then drive the generator to generate electricity becomes one of the options.

[0004] The ram air turbine is a key component of the ram air turbine power generation system. Since the ram air turbine works in a high temperature and high speed environment, the turbine disc is subjected to large thermal stress and centrifugal force, and the working environment is relatively harsh. Therefore, designing a ram air turbine disc that meets the strength requirements is crucial for the safe operation of the ram air turbine system. The traditional design method of the ram air turbine disc requires manual modeling, simulation calculation, and repeated iterations to obtain a satisfactory solution, which is time-consuming.

[0005] Therefore, it is necessary to design a parametric modeling and automatic structural optimization method for ram air turbine disks. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a method for parameterized modeling and automatic structural optimization of a ram air turbine disk.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a method for parameterized modeling and automatic structural optimization of a ram air turbine disk, comprising:

[0009] The 3D model of the ram air turbine disk was established by CATIA based on the direct parametric method;

[0010] Establish a mathematical model for ram air turbine disk strength optimization;

[0011] Optimizing the parameters of the ram air turbine disk through the ram air turbine disk strength optimization mathematical model based on the particle swarm optimization algorithm to obtain the optimization parameters, assigning values ​​to the three-dimensional model of the ram air turbine disk based on the optimization parameters to obtain the three-dimensional model of the ram air turbine disk for analysis;

[0012] Conduct heat transfer-strength coupling analysis on the three-dimensional model of the ram air turbine disk used for analysis, and obtain the ram air turbine disk stress and ram air turbine disk mass calculated by heat transfer-strength coupling;

[0013] The obtained ram air turbine disk stress and ram air turbine disk mass are evaluated to determine whether they have reached the optimization target. If so, the optimization is terminated. If not, the ram air turbine disk parameters are optimized based on the particle swarm optimization algorithm through the ram air turbine disk strength optimization mathematical model.

[0014] Preferably, a three-dimensional model of the ram air turbine disk is established by CATIA based on a direct parameterization method, specifically:

[0015] A three-dimensional model of a ram air turbine disk is established through secondary development of CATIA based on a direct parameterization method, wherein the characteristic parameters involved in establishing the three-dimensional model of the ram air turbine disk include the axial width L1 of the hub surface, the height L2 of the rim surface, the half-thickness L3 of the thinnest part of the disk body, the distance L4 from the thinnest part of the disk body to the axis, the step size L5, the axial half-width L6 of the disk, the thickness L7 of the disk bottom, the radius L8 of the rotating shaft, the rounding radius R1 of the front neck of the rim, the rounding radius R2 of the rear neck of the rim, the rounding radius R3 of the disk waist, the front neck angle C1 of the rim, the rear neck angle C2 of the rim, the expansion angle C3 of the disk body and the step angle C4.

[0016] Preferably, a ram air turbine disk strength optimization mathematical model is established, specifically:

[0017] Select optimization parameters, wherein the cross section of the ram air turbine disk is defined to be axisymmetric, that is, the front neck angle C1 of the rim is equal to the rear neck angle C2 of the rim, and the front neck fillet radius R1 of the rim is equal to the rear neck fillet radius R2 of the rim; define the hub surface axial width L1, step size L5, shaft radius L8 and step angle C4 to be fixed values;

[0018] The design variables are defined as eight, namely, the rim surface height X1, the half thickness of the thinnest part of the disc body X2, the axial half width of the disc X3, the disc bottom thickness X4, the rim front neck fillet radius X5, the disc waist fillet radius X6, the rim front neck angle X7 and the disc body expansion angle X8;

[0019] The constraint condition in the mathematical model of ram air turbine disk strength optimization is defined as strength constraint, which requires that the maximum equivalent stress of the ram air turbine disk does not exceed the ultimate strength of the material, and the objective function requires the disk mass to be minimum.

[0020] The mathematical model for ram air turbine disk strength optimization is established and expressed as:

[0021] for X=[X1,X2,X3,X4,X5,X6,X7,X8] T

[0022] min m(X)

[0023] sts v b

[0024] Where m(X) is the mass of the ram air turbine disk, s v is the maximum equivalent stress of the ram air turbine disk, s b is the allowable stress of the material.

[0025] Preferably, the ram air turbine disk parameters are optimized by using a ram air turbine disk strength optimization mathematical model based on a particle swarm optimization algorithm to obtain optimized parameters, and the three-dimensional model of the ram air turbine disk is assigned values ​​based on the optimized parameters to obtain a three-dimensional model of the ram air turbine disk for analysis, specifically:

[0026] Based on the particle swarm optimization algorithm, the parameters of the ram air turbine disk are optimized through the ram air turbine disk strength optimization mathematical model, the optimization parameters are output, and the combination of the optimization parameters is sent to CATIA to assign values ​​to the established three-dimensional model of the ram air turbine disk, and the three-dimensional model of the ram air turbine disk for analysis is output.

[0027] Preferably, a heat transfer-strength coupling analysis is performed on the three-dimensional model of the ram air turbine disk used for analysis to obtain the ram air turbine disk stress and the ram air turbine disk mass calculated by the heat transfer-strength coupling, specifically:

[0028] The three-dimensional model of the ram air turbine disk for analysis is imported into the ABAQUS platform, and the material properties, rotational speed and thermal boundary conditions of the ram air turbine disk are given for calculation. Through the secondary development of ABAQUS, the heat transfer-strength coupling analysis function is encapsulated as the strengthAnalyze() function, and the volume measurement function is encapsulated as the volumeCalculate() function. By calling the strengthAnalyze() function and the volumeCalculate() function, the ram air turbine disk stress and the ram air turbine disk mass calculated by the heat transfer-strength coupling are output.

[0029] ​Preferably, the material of the ram air turbine disk is given as K418, the rotation speed is defined as the design rotation speed of the ram air turbine disk, the thermal boundary condition input is a given hub surface temperature T1, and the disk core temperature is T1-150°C.

[0030] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0031] The present invention provides a method for parameterized modeling and automatic structural optimization of a ram air turbine disk. The method comprises establishing a three-dimensional model of a ram air turbine disk through CATIA based on a direct parameterization method, establishing a ram air turbine disk strength optimization mathematical model, optimizing the parameters of the ram air turbine disk through the ram air turbine disk strength optimization mathematical model based on a particle swarm optimization algorithm, obtaining optimization parameters, assigning values ​​to the three-dimensional model of the ram air turbine disk based on the optimization parameters, obtaining a three-dimensional model of the ram air turbine disk for analysis, performing heat transfer-strength coupling analysis on the three-dimensional model of the ram air turbine disk for analysis, obtaining the ram air turbine disk stress calculated by the heat transfer-strength coupling and the ram air turbine disk stress. The quality of the wheel disc is evaluated by evaluating the obtained ram air turbine disc stress and ram air turbine disc quality to determine whether they have reached the optimization goal. If so, the optimization is terminated. If not, the ram air turbine disc parameter optimization is continued through the ram air turbine disc strength optimization mathematical model based on the particle swarm optimization algorithm. The method realizes automation for mechanical operation links, such as mesh division and numerical transfer, which greatly speeds up the speed and is not prone to errors. The method realizes the establishment and use of parameterized models, saving the time used for establishing and adjusting models. The method supports automatic setting of examples, which only needs to be set manually once, and the template can be automatically applied in subsequent calculations, reducing the number of repeated operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 A flow chart of a method provided by an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of a technical route provided for an embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram of the structure of the ram air turbine disc of the present invention;

[0036] Figure 4A stress distribution cloud diagram of a ram air turbine disk provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The object of the present invention is to provide a method for parametric modeling and automatic structural optimization of a ram air turbine disk, which can realize parametric modeling and automatic structural optimization of a ram air turbine disk and facilitate the design of the ram air turbine disk.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Figure 1 A flow chart of a method provided by an embodiment of the present invention, Figure 2 A schematic diagram of a technical route provided by an embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the present invention provides a method for parameterized modeling and automatic structural optimization of a ram air turbine disk, comprising:

[0041] Step 100: Establishing a three-dimensional model of the ram air turbine disk through CATIA based on a direct parameterization method;

[0042] Step 200: Establishing a ram air turbine disk strength optimization mathematical model;

[0043] Step 300: Optimizing the parameters of the ram air turbine disk using the ram air turbine disk strength optimization mathematical model based on a particle swarm optimization algorithm to obtain optimized parameters, assigning values ​​to the three-dimensional model of the ram air turbine disk based on the optimized parameters to obtain the three-dimensional model of the ram air turbine disk for analysis;

[0044] Step 400: performing heat transfer-strength coupling analysis on the three-dimensional model of the ram air turbine disk for analysis, and obtaining the ram air turbine disk stress and the ram air turbine disk mass calculated by heat transfer-strength coupling;

[0045] Step 500: Evaluate the obtained ram air turbine disk stress and ram air turbine disk mass to determine whether they have reached the optimization target. If so, terminate the optimization. If not, continue to optimize the ram air turbine disk parameters based on the particle swarm optimization algorithm through the ram air turbine disk strength optimization mathematical model.

[0046] It should be noted that Figure 2 The optimizer described in is the ram air turbine disc strength optimization mathematical model described in the present invention;

[0047] In step 100, a three-dimensional model of the ram air turbine disk is established by CATIA based on a direct parameterization method, specifically:

[0048] The 3D model of the ram air turbine disk was established through secondary development of CATIA based on direct parametric method;

[0049] That is, the turbine disk is directly designed with customized feature parameters. Through CATIA secondary development, the functions of drawing points, drawing lines, drawing circles, creating sketches, opening / saving files, etc. in CATIA are encapsulated into the catiaModel() function. After calling this function, the three-dimensional model of the turbine disk can be automatically established based on the set model parameters.

[0050] The advantage of the direct parameterization method over the parameterization method based on modification is that the complete turbine disk modeling can be realized through the given characteristic parameters. The model established by the direct parameterization method is more flexible and applicable, and can realize the modeling of turbine disks of different sizes and shapes.

[0051] Among them, the structural schematic diagram of the ram air turbine disc is as follows Figure 3 As shown, the characteristic parameters involved in establishing the three-dimensional model of the ram air turbine disk include the axial width L1 of the hub surface, the height L2 of the rim surface, the half-thickness L3 of the thinnest part of the disk body, the distance L4 from the thinnest part of the disk body to the axis, the step size L5, the axial half-width L6 of the disk, the thickness L7 of the disk bottom, the radius of the rotating shaft L8, the fillet radius R1 of the front neck of the rim, the fillet radius R2 of the rear neck of the rim, the fillet radius R3 of the disk waist, the front neck angle C1 of the rim, the rear neck angle C2 of the rim, the expansion angle C3 of the disk body and the step angle C4.

[0052] In step 200, a ram air turbine disk strength optimization mathematical model is established, specifically:

[0053] In order to reduce the design space and the number of iterations required for optimization, some parameters are selected to be fixed, and the cross-section of the ram air turbine disk is defined to be axisymmetric, that is, the front neck angle C1 of the rim is equal to the rear neck angle C2 of the rim, and the front neck fillet radius R1 of the rim is equal to the rear neck fillet radius R2 of the rim;

[0054] The rotation axis radius L8 is defined as a fixed value, which is given by the overall structural design of the ram air turbine power generation system;

[0055] The axial width L1 of the hub surface takes a fixed value, generally the axial chord length of the blade plus 3-5mm;

[0056] After the wheel disc diameter is determined, the step size L5 and the step angle C4 also take fixed values;

[0057] The design variables are defined as eight, namely, the rim surface height X1, the half thickness of the thinnest part of the disc body X2, the axial half width of the disc X3, the disc bottom thickness X4, the rim front neck fillet radius X5, the disc waist fillet radius X6, the rim front neck angle X7 and the disc body expansion angle X8;

[0058] The constraint condition in the mathematical model of ram air turbine disk strength optimization is defined as strength constraint, which requires that the maximum equivalent stress of the ram air turbine disk does not exceed the ultimate strength of the material, and the objective function requires the disk mass to be minimum.

[0059] The mathematical model for ram air turbine disk strength optimization is established and expressed as:

[0060] for X=[X1,X2,X3,X4,X5,X6,X7,X8] T

[0061] min m(X)

[0062] sts v b

[0063] Where m(X) is the mass of the ram air turbine disk, s v is the maximum equivalent stress of the ram air turbine disk, s b is the allowable stress of the material.

[0064] In step 300, the ram air turbine disk parameters are optimized by using the ram air turbine disk strength optimization mathematical model based on the particle swarm optimization algorithm to obtain the optimization parameters, and the three-dimensional model of the ram air turbine disk is assigned based on the optimization parameters to obtain the three-dimensional model of the ram air turbine disk for analysis, specifically:

[0065] Based on the particle swarm optimization algorithm, the ram air turbine disk parameters are optimized through the ram air turbine disk strength optimization mathematical model, the optimization parameters are output, the combination of the optimization parameters is sent to CATIA, the established 3D model of the ram air turbine disk is assigned, and the 3D model of the ram air turbine disk for analysis is output;

[0066] ​The present invention provides an embodiment, wherein the height range of the given wheel rim surface is 1mm-5mm, the initial value is 3.939mm, the half thickness range of the thinnest part of the disc body is 1mm-10mm, the initial value is 4.151mm, the half width range of the wheel disc axial direction is 5mm-50mm, the initial value is 22.157mm, the disc bottom thickness range is 2mm-20mm, the initial value is 7.878mm, the wheel rim front neck fillet radius range is 2mm-20mm, the initial value is 5.00mm, the disc waist fillet radius range is 2mm-20mm, the initial value is 7.878mm, the wheel rim front neck angle range is 80°-120°, the initial value is 100°, and the disc body expansion angle range is 1°-30°, the initial value is 4.764°;

[0067] The output optimization parameters are: rim surface height of 3.411mm, half thickness of the thinnest part of the disk body of 3.383mm, axial half width of the disk of 21.195mm, disk bottom thickness of 6.919mm, rim front neck fillet radius of 5.082mm, disk waist fillet radius of 7.536mm, rim front neck angle of 100°, and disk body expansion angle of 4.457°. Based on the optimization parameters, the three-dimensional model of the ram air turbine disk is assigned to obtain the three-dimensional model of the ram air turbine disk for analysis.

[0068] In step 400, a heat transfer-strength coupling analysis is performed on the three-dimensional model of the ram air turbine disk for analysis to obtain the ram air turbine disk stress and the ram air turbine disk mass calculated by the heat transfer-strength coupling, specifically:

[0069] The three-dimensional model of the ram air turbine disk used for analysis is imported into the ABAQUS platform, and the material properties, rotation speed and thermal boundary conditions of the ram air turbine disk are given for calculation. Through the secondary development of ABAQUS, the heat transfer-strength coupling analysis function is encapsulated as the strengthAnalyze() function, and the volume measurement function is encapsulated as the volumeCalculate() function. By calling the strengthAnalyze() function and the volumeCalculate() function, the ram air turbine disk stress and the ram air turbine disk mass calculated by the heat transfer-strength coupling are output;

[0070] The material of the ram air turbine disk is given as K418, the rotation speed is defined as the design rotation speed of the ram air turbine disk, which is 40000 rpm in this embodiment, and the thermal boundary condition input is a given hub surface temperature T1, and a disk core temperature of T1-150°C, wherein the wheel rim temperature is 768K and the disk core temperature is 618K in this embodiment;

[0071] Based on this embodiment, through multiple rounds of iterative optimization, the wheel mass that meets the optimization target is 2.1kg, and the maximum equivalent stress of the wheel is 742.2Mpa, which is less than the allowable stress of the material under the temperature condition of 890Mpa. Among them, the parameter change table of the ram air turbine disk optimization result is shown in Table 1, and the performance parameter change table of the ram air turbine disk strength optimization result is shown in Table 2. The present invention also provides a stress distribution cloud diagram of the ram air turbine disk as shown in Figure 4 shown.

[0072] Table 1 Impeller strength optimization result parameter change table

[0073]

[0074] Table 2 Performance parameter changes of impeller strength optimization results

[0075]

[0076] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0077] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for parametric modeling and automatic structural optimization of a ram air turbine disk, characterized in that: include: The 3D model of the ram air turbine disk was established by CATIA based on the direct parametric method; Establish a mathematical model for ram air turbine disk strength optimization; Optimizing the parameters of the ram air turbine disk through the ram air turbine disk strength optimization mathematical model based on the particle swarm optimization algorithm to obtain the optimization parameters, assigning values ​​to the three-dimensional model of the ram air turbine disk based on the optimization parameters to obtain the three-dimensional model of the ram air turbine disk for analysis; Conduct heat transfer-strength coupling analysis on the three-dimensional model of the ram air turbine disk used for analysis, and obtain the ram air turbine disk stress and ram air turbine disk mass calculated by heat transfer-strength coupling; The obtained ram air turbine disk stress and ram air turbine disk mass are evaluated to determine whether they have reached the optimization target. If so, the optimization is terminated. If not, the ram air turbine disk parameters are optimized based on the particle swarm optimization algorithm through the ram air turbine disk strength optimization mathematical model.

2. The method according to claim 1, characterized in that The 3D model of the ram air turbine disk is established by CATIA based on the direct parametric method, specifically: A three-dimensional model of a ram air turbine disk is established through secondary development of CATIA based on a direct parameterization method, wherein the characteristic parameters involved in establishing the three-dimensional model of the ram air turbine disk include the axial width L1 of the hub surface, the height L2 of the rim surface, the half-thickness L3 of the thinnest part of the disk body, the distance L4 from the thinnest part of the disk body to the axis, the step size L5, the axial half-width L6 of the disk, the thickness L7 of the disk bottom, the radius L8 of the rotating shaft, the rounding radius R1 of the front neck of the rim, the rounding radius R2 of the rear neck of the rim, the rounding radius R3 of the disk waist, the front neck angle C1 of the rim, the rear neck angle C2 of the rim, the expansion angle C3 of the disk body and the step angle C4.

3. The method according to claim 2, characterized in that A mathematical model for ram air turbine disk strength optimization is established, specifically: Select optimization parameters, wherein the cross section of the ram air turbine disk is defined to be axisymmetric, that is, the front neck angle C1 of the rim is equal to the rear neck angle C2 of the rim, and the front neck fillet radius R1 of the rim is equal to the rear neck fillet radius R2 of the rim; define the hub surface axial width L1, step size L5, shaft radius L8 and step angle C4 to be fixed values; The design variables are defined as eight, namely, the rim surface height X1, the half thickness of the thinnest part of the disc body X2, the axial half width of the disc X3, the disc bottom thickness X4, the rim front neck fillet radius X5, the disc waist fillet radius X6, the rim front neck angle X7 and the disc body expansion angle X8; The constraint condition in the mathematical model of ram air turbine disk strength optimization is defined as strength constraint, which requires that the maximum equivalent stress of the ram air turbine disk does not exceed the ultimate strength of the material, and the objective function requires the disk mass to be minimum. The mathematical model for ram air turbine disk strength optimization is established and expressed as: for X=[X1,X2,X3,X4,X5,X6,X7,X8] T min m(X) s.t.s v <s b Where m(X) is the mass of the ram air turbine disk, s v is the maximum equivalent stress of the ram air turbine disk, s b is the allowable stress of the material.

4. The method according to any one of claims 1, 2 or 3, characterized in that: Based on the particle swarm optimization algorithm, the ram air turbine disk parameters are optimized through the ram air turbine disk strength optimization mathematical model to obtain the optimization parameters. Based on the optimization parameters, the three-dimensional model of the ram air turbine disk is assigned values ​​to obtain the three-dimensional model of the ram air turbine disk for analysis, which is specifically: Based on the particle swarm optimization algorithm, the parameters of the ram air turbine disk are optimized through the ram air turbine disk strength optimization mathematical model, the optimization parameters are output, and the combination of the optimization parameters is sent to CATIA to assign values ​​to the established three-dimensional model of the ram air turbine disk, and the three-dimensional model of the ram air turbine disk for analysis is output.

5. The method according to any one of claims 1, 2, 3 or 4, characterized in that: A heat transfer-strength coupling analysis is performed on the three-dimensional model of the ram air turbine disk used for analysis, and the ram air turbine disk stress and ram air turbine disk mass calculated by heat transfer-strength coupling are obtained, specifically: The three-dimensional model of the ram air turbine disk for analysis is imported into the ABAQUS platform, and the material properties, rotational speed and thermal boundary conditions of the ram air turbine disk are given for calculation. Through the secondary development of ABAQUS, the heat transfer-strength coupling analysis function is encapsulated as the strengthAnalyze() function, and the volume measurement function is encapsulated as the volumeCalculate() function. By calling the strengthAnalyze() function and the volumeCalculate() function, the ram air turbine disk stress and the ram air turbine disk mass calculated by the heat transfer-strength coupling are output.

6. The method according to claim 5, characterized in that The material of the ram air turbine disk is given as K418, the rotation speed is defined as the design rotation speed of the ram air turbine disk, the thermal boundary condition input is a given hub surface temperature T1, and the disk core temperature is T1-150°C.

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