CN112287455A - Method for batch extraction of pneumatic loads of complex aircraft configuration - Google Patents
Method for batch extraction of pneumatic loads of complex aircraft configuration Download PDFInfo
- Publication number
- CN112287455A CN112287455A CN202011178100.5A CN202011178100A CN112287455A CN 112287455 A CN112287455 A CN 112287455A CN 202011178100 A CN202011178100 A CN 202011178100A CN 112287455 A CN112287455 A CN 112287455A
- Authority
- CN
- China
- Prior art keywords
- pneumatic
- discrete
- space
- data
- data set
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000605 extraction Methods 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 41
- 238000004364 calculation method Methods 0.000 claims abstract description 56
- 238000009826 distribution Methods 0.000 claims description 16
- 238000004088 simulation Methods 0.000 claims description 12
- 238000004458 analytical method Methods 0.000 claims description 11
- 238000012545 processing Methods 0.000 claims description 11
- 230000006870 function Effects 0.000 claims description 10
- 239000011159 matrix material Substances 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 5
- 125000004122 cyclic group Chemical group 0.000 claims description 3
- 239000012530 fluid Substances 0.000 claims description 3
- 238000013461 design Methods 0.000 description 12
- 230000008859 change Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 8
- 239000006185 dispersion Substances 0.000 description 6
- 238000012546 transfer Methods 0.000 description 4
- 238000012938 design process Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 238000010205 computational analysis Methods 0.000 description 1
- 238000013075 data extraction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003028 elevating effect Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000010845 search algorithm Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/15—Vehicle, aircraft or watercraft design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Automation & Control Theory (AREA)
- Aviation & Aerospace Engineering (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Image Generation (AREA)
Abstract
The invention relates to a complex airplane configuration pneumatic load batch extraction method, aiming at forming an efficient and reliable pneumatic load extraction process and method. The method is flexible, efficient and strong in adaptability, and can quickly finish batch extraction and formatted output of various complex airplane configuration pneumatic loads. And moreover, the precision of the extraction result and the reliability of the structural load calculation result can be ensured by adopting a high-fidelity geometric shape discretization mode and a high-precision spatial interpolation method.
Description
Technical Field
The invention belongs to the field of aircraft aerodynamics and strength calculation, and relates to a method for extracting an aerodynamic load result aiming at a complex aircraft configuration based on a space discrete point data set.
Background
The overall stress condition of the whole aircraft structure and the maximum stress state of each component are obtained through structural strength analysis in the aircraft design process, and a sufficient structural strength margin is reserved in the design on the basis of the overall stress condition and the maximum stress state so as to ensure the safety of the aircraft structure in actual flight. As an important basis for strength analysis and structural design, the accurate calculation of the aerodynamic load of the airplane not only can improve the reliability of the strength analysis and the structural design, but also is beneficial to reducing unnecessary structural weight on the airplane and improving the overall aerodynamic characteristics and the use economy of the airplane. Therefore, the load calculation is very important to the design of the airplane.
In the initial stage of aircraft design, calculation and check of the aerodynamic characteristics and the structural loads in batches are often performed according to different configurations, different rudder states and different flight attitudes in the whole flight envelope of the aircraft. Because the time difference between the pneumatic calculation and the structural load calculation of the RANS (Reynolds-Averaged Navier-Stokes) method is large in the single state calculation, the time required by the pneumatic calculation is often dozens or hundreds of times of that of the structural calculation. At this time, the real-time data transmission and calculation using pneumatics and structures is inefficient and difficult to adapt to engineering requirements. In addition, the working platforms of the pneumatic and structure solvers are sometimes inconsistent, large-scale calculation of the pneumatic characteristics of complex configurations is usually completed on a supercomputing platform, and the structural load solution is only performed on a workstation or a personal computer. The difference in platforms makes real-time two-way transfer of data between pneumatic and structural load calculation modules more difficult. In view of this, the present application proposes a more efficient solution, in which the whole aerodynamic and structural load calculation is divided into two stages, and the batch extraction and transfer of data are completed by a complex configuration aerodynamic load batch extraction method based on a spatial discrete point data set.
At present, many patents related to the aerodynamic loads have been published in China, such as Cheneli's "an analysis method for the aerodynamic loads" of the institute for designing a Sian aircraft, a company, the aviation industry, China, and "a method and a system for obtaining the aerodynamic loads of aircraft parts" of the Korean institute for designing an aircraft, a company, the Limited liability of commercial aircraft, China, and the like. However, the main focus of the methods is the specific analysis method of the aerodynamic load or the extraction method of the related pressure distribution and force coefficient, and no related patent relates to the batch extraction and processing method of the calculation result of the aerodynamic load of the complex airplane configuration.
Disclosure of Invention
The technical problem solved by the invention is as follows: in order to make up for the defects of the prior art, the invention aims to form an efficient and reliable pneumatic load extraction process and method, based on a numerical simulation result obtained by an RANS method and a space discrete point data set obtained by discretization of the geometric shape of a model, a pneumatic load distribution database meeting a certain data format is obtained through searching and three-dimensional space interpolation and is used as input for finite element solution of a next structure.
The technical scheme of the invention is as follows: a method for extracting aerodynamic loads of complex airplane configurations in batches comprises the following steps: step 1: carrying out space discretization processing on the three-dimensional pneumatic shape of the unmanned aerial vehicle with a complex configuration to form an available space discrete point data set;
step 2: the numerical simulation calculation under different control plane deflection angles and different flight states at high and low speeds is completed to obtain corresponding object plane pressure distribution results stored in a PLOT3D format, and the numerical simulation calculation method comprises the following substeps:
step 2.1: dividing a structured computing grid aiming at different high and low speed configurations;
step 2.2: carrying out large-scale calculation analysis by using a computational fluid dynamics solver to obtain object plane aerodynamic load results in PLOT3D format in all states;
and step 3: a three-dimensional shape function space point interpolation method is compiled by adopting Fortran language, based on a space discrete point data set, a pressure coefficient result on each discrete point is extracted from an object plane result in a PLOT3D format by three-dimensional space point interpolation, and batch extraction work of pneumatic loads of all state numerical value calculation results is completed by cyclic interpolation calculation, and the method comprises the following substeps:
step 3.1: preparing an input file of a program, wherein the input file comprises a path stored by each PLOT3D format calculation result and corresponding state variables, including Mach number, flight altitude, attack angle, sideslip angle and each control surface deflection angle;
step 3.2: reading the object plane pneumatic load calculation result and the state variable in a PLOT3D format by utilizing a Fortran language writing program, and storing all object plane point coordinates and corresponding pneumatic loads as an array as an interpolation data source;
step 3.3: sequentially reading in the spatial discrete point data set coordinate matrix formed in the step 1 in an array form by using a Fortran language;
step 3.4: establishing a high-precision shape function three-dimensional space point interpolation method by using a Fortran language writing program;
step 3.5: circularly performing the step 3.2 to the step 3.4 until the interpolation extraction work of the object surface pneumatic load under all the states is completed;
and 4, step 4: and (3) exporting the pneumatic load data according to a format in a space discrete point data set by utilizing a Fortran language writing program, so that the object plane pneumatic load result in a PLOT3D format is changed into the pneumatic load data stored in an array format.
The further technical scheme of the invention is as follows: the step 1 comprises the following substeps:
step 1.1: the whole airplane is divided into 11 types of airframes, central connecting sections, nacelles, hangers, wings, horizontal tails, vertical tails, flaps, ailerons, elevators, rudders and the like, and the total number of the parts is 25;
step 1.2: selecting respective space discrete profiles and discrete point numbers for each type of components according to the value ranges given in the table 1;
step 1.3: carrying out discretization processing on the pneumatic appearance of each part according to the given section and the number of discrete points of each part;
step 1.4: and respectively deriving the three-dimensional space coordinate data of all the points by using the components as distinctions to form a space discrete point data set.
The further technical scheme of the invention is as follows: the specific principle selected in the step 1.2 is as follows: given enough profiles and discrete points to better represent the true aerodynamic profile of the part, too many profiles and discrete points can result in an overall computationally expensive process.
The further technical scheme of the invention is as follows: in step 1.4, all data are divided into P data matrices, and each matrix includes NiA data column, each data column having MiAnd (4) grouping the three-dimensional point data. Wherein P represents the number of parts, NiRepresenting the number of discrete wire frames, M, corresponding to a componentiThe number of discrete points in each line frame is shown, xj, yj, zj (j is 1,2, … M)i) The three-dimensional coordinates of the spatial point. The spatial discrete point data set is composed of P Ni×MiAnd (i ═ 1,2, … P) in the data matrix. For the fuselage component in this example, its discrete point data set contains 50 x 50 spatial points, which are used to describe its three-dimensional shape.
Effects of the invention
The invention has the technical effects that: the invention provides a complex-configuration pneumatic load batch extraction method. The method is flexible, efficient and strong in adaptability, and can quickly finish batch extraction and formatted output of various complex airplane configuration pneumatic loads. And moreover, the precision of the extraction result and the reliability of the structural load calculation result can be ensured by adopting a high-fidelity geometric shape discretization mode and a high-precision spatial interpolation method.
Drawings
Table 1 shows the number of sections and discrete points corresponding to each component of a complex configuration unmanned aerial vehicle.
FIG. 1 is a schematic diagram of an unmanned aerial vehicle layout form and geometric shape with a complex configuration
FIG. 2 is a schematic view of a detail of the spatial dispersion of the nacelle profile.
Fig. 3 is a schematic view of the wing and elevator profile space dispersion.
Fig. 4 is a schematic outline view of each part of the complex configuration after wire-frame discretization.
Fig. 5 is a schematic outline view of each part of the complex configuration after three-dimensional point discretization.
Fig. 6 is a data format of the generated spatially discrete point data set.
Fig. 7 shows the plane surface mesh used in the numerical simulation calculation, and also the mesh used in the interpolation of the numerical simulation object plane results.
FIG. 8 is a schematic diagram of spatial point interpolation during pneumatic load extraction.
FIG. 9 is a comparison of calculated and interpolated pressure coefficient profiles at a full span position where the airfoil surface is 83% times the plane of symmetry.
FIG. 10 is a comparison of calculated and interpolated pressure coefficient distribution curves at a station on the outboard nacelle surface 20% of the chord length of the nacelle from the leading edge.
FIG. 11 is a schematic diagram of a pneumatic load extraction process and method.
Reference numerals: the airplane body, the central connecting section, the inner nacelle and the hanging rack, the outer nacelle and the hanging rack, the wings, the horizontal tail, the vertical tail, the wing flap, the aileron and the elevating rudder,
-a rudder.
All the following parameters are taken as a reference coordinate system by a wind axis system.
Cp-object plane pressure coefficient; x-coordinate value in flow direction; y-coordinate value along wingspan direction of the aircraft; p is the total number of components contained in the airplane; n-the number of discrete wire frames corresponding to the component; m-the number of discrete points corresponding to each discrete wire frame on the component; (x1 y1 z1), (x2 y2 z2) -discrete point coordinates.
Detailed Description
Referring to fig. 1-11, a set of general pneumatic load extraction methods is established for batch processing and extraction of pneumatic load data of complex airplane configurations. By using the method, the pressure distribution characteristic data of each single component of the airplane in different flight states can be quickly and accurately obtained, and batch output is carried out according to a certain data format; the method has strong adaptability, is suitable for various complex airplane configurations, and only needs to update the discrete point data set after the configuration is changed without any change on the program and the method; the data extraction module adopts an advanced interpolation algorithm, and can fully ensure the consistency between the extracted pressure distribution data and the calculation result.
The invention discloses a complex configuration pneumatic load batch extraction method, which comprises the following specific implementation steps:
1. based on a geometric model obtained in the pneumatic shape design stage, firstly dispersing the geometric shape into wire frames according to a given data format, and then dispersing all the wire frames into space points according to the curvature change characteristics of the wire frame shape to form a space dispersion point data set grouped according to airplane parts;
2. obtaining a batch numerical simulation calculation result aiming at a complex airplane configuration, wherein the result mainly comprises a three-dimensional coordinate of a point on a configuration object surface and corresponding pressure distribution;
3. compiling a three-dimensional shape function space point interpolation method through Fortran language, and extracting pressure coefficient results on corresponding discrete points from object plane results through three-dimensional point coordinate search and space interpolation based on a space discrete point data set;
4. deriving data in a given format as input to the computation of the structural loads;
5. and carrying out batch structural load calculation and analysis, and providing design feedback for the optimal design of the structure and the pneumatic appearance according to the analysis result.
The invention achieves the above-mentioned objects by the following technical scheme.
In order to enable the pneumatic load batch extraction method to have universality, the core part of the whole extraction method adopts a modularized design idea. The pneumatic load extraction program has high independence, and the main input of the pneumatic load extraction program is divided into a numerical calculation result and a space discrete point data set. The advantage of processing in this way is that the method for extracting aerodynamic loads can be applied to various types of complex aircraft configurations, and after the configuration is changed, only the numerical calculation result and the discrete point data set need to be updated, and no change needs to be made to the program and the method. Meanwhile, the engineering practicability of the pneumatic load extraction method is further improved due to the modularized design. In the design process, analysis and processing of different rudder deflection states or different flight attitudes can be easily added on the basis of the original configuration, and the workload cannot be greatly increased.
In order to realize the formatted output of the pneumatic load data, the geometrical shape of the airplane is discretized into space points according to a given format, and a space discrete point data set grouped according to airplane components is formed and used as a template for the interpolation of the subsequent calculation result.
In order to enable the discrete space points to accurately describe the geometric shape of an object plane, firstly, a space wire frame capable of better describing the main layout form and the geometric characteristics of components is obtained through high-fidelity discretization of the geometric shape of each component of the airplane, then, point discretization is further carried out on the space wire frame, and local encryption processing is carried out according to the curvature change characteristics of the wire frame shape so as to better simulate regions with larger curvature changes, such as the leading edge of the wing.
In order to ensure the consistency of the pneumatic load extraction data and the calculation result, a neighborhood search algorithm and a high-precision shape function interpolation method are utilized in the extraction method to extract the pressure coefficient result on the corresponding space discrete point from the object plane result.
In order to realize batch data processing, an input file is required to be given to a pneumatic load extraction program, and the input file mainly comprises a path stored by each calculation result and corresponding state variables, including Mach number, flight altitude, attack angle, sideslip angle and deflection angle of each control surface; based on the method, the extraction program can automatically call the numerical simulation calculation result and the corresponding space discrete point data set according to the input file, and quickly finish object plane interpolation and data formatting output.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are further described in detail below with reference to the accompanying drawings and specific examples.
The present embodiment is described and illustrated in detail with respect to the batch extraction work and flow of a complex unmanned proof mechanical pneumatic load.
Step 1: carrying out space discretization processing on the three-dimensional pneumatic shape of the unmanned aerial vehicle with a complex configuration to form an available space discrete point data set;
step 1.1: the unmanned aerial vehicle in this embodiment adopts a special layout form of four-engine, two-fuselage, and a pi-shaped empennage, and a schematic diagram of the geometric shape thereof is shown in fig. 1. Firstly, dividing the whole airplane into 11 types of fuselages, central connecting sections, nacelles, hangers, wings, horizontal tails, vertical tails, flaps, ailerons, elevators, rudders and the like, wherein the total number of the parts is 25;
step 1.2: selecting respective space discrete profiles and discrete point numbers for each type of components according to the value ranges given in the table 1; the specific selection principle is as follows: enough sections and discrete points are given to better represent the real pneumatic appearance of the part, and the number of the sections and the discrete points is excessive, so that the overall calculation amount is excessive;
step 1.3: and carrying out discretization processing on the pneumatic appearance of each part according to the given section and the discrete point number of each part. As shown in fig. 2, for parts of the fuselage, nacelle, etc. where the curvature changes are relatively gentle, the spatial sections are arranged uniformly in the flow direction and the discrete points are arranged uniformly on each section; as shown in fig. 3, spatial cross sections of the wing, the horizontal vertical fin, the control surface, and the like are uniformly arranged along the root to the tip of the wing, and a leading edge portion having a large curvature change is subjected to a certain encryption process when points are arranged on the cross sections. After the discretization process of all the components is completed, the full machine profile, represented by a discrete line box as shown in fig. 4, and the full machine profile, represented by a spatially discrete point in fig. 5, are obtained. It can be seen that the main characteristics and contours of the three-dimensional geometrical shapes of the parts of the complex configuration are well preserved through the discrete mode;
step 1.4: after the spatial point dispersion of the whole machine is completed, three-dimensional spatial coordinate data of all the points are respectively derived by parts for distinguishing, and a spatial discrete point data set is formed. The specific data format of the data set is shown in FIG. 6, where all data is divided into P dataMatrices, each matrix including NiA data column, each data column having MiAnd (4) grouping the three-dimensional point data. Wherein P represents the number of parts, NiRepresenting the number of discrete wire frames, M, corresponding to a componentiThe number of discrete points in each line frame is shown, xj, yj, zj (j is 1,2, … M)i) The three-dimensional coordinates of the spatial point. The spatial discrete point data set is composed of P Ni×MiAnd (i ═ 1,2, … P) in the data matrix. For the fuselage component in this example, its discrete point data set contains 50 x 50 spatial points, which are used to describe its three-dimensional shape.
Step 2: numerical simulation calculation under different control plane deflection angles and different flight states at high and low speeds is completed, and corresponding object plane pressure distribution results stored in a PLOT3D format are obtained;
step 2.1: and dividing the structured computing grids aiming at different high and low speed configurations. Full machine surface mesh as shown in fig. 7, the three-dimensional mesh points of the surface are the basis for the next step of spatial interpolation. It can be seen that the grid has a large difference in density and point distribution from the surface discrete points in the dataset;
step 2.2: and (4) carrying out large-scale calculation analysis by using a computational fluid dynamics solver to obtain the object plane aerodynamic load results in PLOT3D format in all states.
And step 3: a Fortran language is adopted to write a three-dimensional shape function space point interpolation method, based on a space discrete point data set, a pressure coefficient result on each discrete point is extracted from an object plane result in a PLOT3D format through three-dimensional space point interpolation, and batch extraction work of pneumatic loads of all state numerical value calculation results is completed through cyclic interpolation calculation;
step 3.1: preparing an input file of a program, wherein the input file mainly comprises a path stored by each PLOT3D format calculation result and corresponding state variables, including Mach number, flight altitude, attack angle, sideslip angle and each control surface deflection angle;
step 3.2: reading the object plane pneumatic load calculation result and the state variable in a PLOT3D format by utilizing a Fortran language writing program, and storing all object plane point coordinates and corresponding pneumatic loads as an array as an interpolation data source;
step 3.3: sequentially reading in the spatial discrete point data set coordinate matrix formed in the step 1 in an array form by using a Fortran language;
step 3.4: and establishing a high-precision shape function three-dimensional space point interpolation method by using a Fortran language writing program. As shown in fig. 8, for each three-dimensional point in the spatial discrete point data set, an interpolation relationship is established between spatial points of different coordinates by the spatial interpolation method, so that the aerodynamic load result on the object plane grid point is interpolated to the three-dimensional point. FIGS. 9 and 10 are comparisons of calculated and interpolated pressure coefficient distribution curves at positions where the wing surface is 83% of the full span length of the aircraft from the plane of symmetry and at positions where the outboard nacelle surface is 20% of the nacelle chord length from the leading edge. Therefore, the interpolation data is basically consistent with the original calculation result, the pressure distribution characteristics of the local station can be better reflected, and the requirement of structural load calculation on the data precision can be completely met;
step 3.5: and (5) circularly performing the step 3.2 to the step 3.4 until the interpolation extraction work of the object plane pneumatic load under all the states is completed.
And 4, step 4: exporting the pneumatic load data according to a format of a space discrete point data set by utilizing a Fortran language writing program, namely supplementing a column of load data after three-dimensional point coordinates to change the load data into (x y z Cp), so that an object plane pneumatic load result in a PLOT3D format is changed into pneumatic load data stored in an array format;
table 1 shows the number of the sections and discrete points corresponding to each component of an unmanned aerial vehicle with a complex configuration, and the corresponding value ranges. The full machine geometry is also discretized according to the parameters given in the table and forms a usable set of spatial discrete point data.
Fig. 1 is a schematic view of the layout form and the geometric shape of an unmanned aerial vehicle with a complex configuration, wherein the configuration comprises 11 types of fuselages, central connecting sections, nacelles, pylons, wings, horizontal tails, vertical tails, flaps, ailerons, elevators, rudders and the like, and the total number of the components is 25.
Fig. 2 and 3 are detailed schematic diagrams of nacelle profile space dispersion and wing and elevator profile space dispersion, respectively. The aircraft with complex configuration comprises various types of components, and for the components with gentle curve change of the nacelle, the point distribution on the wire frame can adopt an approximately uniform distribution mode; for the part of the wing with the severe change of the curvature of the leading edge, proper encryption is needed to better simulate the change of the shape.
Fig. 4 is a schematic outline view of each part of the complex configuration after wire-frame discretization. Fig. 5 is a schematic external view of each part of the complex configuration after three-dimensional space point discretization is further performed on each part of the complex configuration on the basis of fig. 4. It can be seen that the main features and contours of the three-dimensional geometric shapes of the various components of the complex configuration are well preserved after spatial discretization based on the parameters in table 1.
Fig. 6 is a data format of the generated spatially discrete point data set. Wherein, P represents the number of components, N represents the number of wire frames corresponding to a certain component, M represents the number of discrete points on each wire frame, and (x y z) is the three-dimensional coordinate of the space point. The spatial discrete point data set is composed of P data matrices of Ni × Mi (i ═ 1,2, … P). For the fuselage component in this example, its discrete point data set contains 50 x 50 spatial points, which are used to describe its three-dimensional shape.
Fig. 7 shows the plane surface mesh used in the numerical simulation calculation, and also the mesh used in the interpolation of the numerical simulation object plane results. The grid has a large difference between the density and the point distribution and the surface discrete points in the data set, so that a high-precision spatial interpolation method needs to be adopted to ensure the consistency of an interpolation result and a CFD calculation result.
FIG. 8 is a schematic diagram of spatial point interpolation during pneumatic load extraction. The curved surface represents the structured surface mesh employed by the aircraft configuration in the CFD computation, and the dots represent spatially discrete points in the dataset. In the actual data interpolation transfer process, firstly, a relation between a surface grid point and a space discrete point is established based on a shape function three-dimensional space point interpolation method, and then, the interpolation transfer of data on the space point is carried out by utilizing the interpolation method.
FIG. 9 is a comparison of calculated and interpolated pressure coefficient profiles at a full span position where the airfoil surface is 83% times the plane of symmetry. FIG. 10 is a comparison of calculated and interpolated pressure coefficient distribution curves at a station on the outboard nacelle surface 20% of the chord length of the nacelle from the leading edge. The interpolation data is basically consistent with the original calculation result, the pressure distribution characteristics of the local station can be better reflected, and the requirement of structural load calculation on data accuracy can be completely met.
FIG. 11 is a schematic diagram of a pneumatic load extraction process and method. Firstly, a space discrete point data set grouped according to airplane components is obtained by dispersing space points of the geometrical shape of the airplane configuration and is used as a reference for aerodynamic load interpolation and data output. Meanwhile, the object plane aerodynamic load results in different flight states are obtained through batch numerical calculation. And then, the pneumatic load data results of all the component surfaces can be obtained through interpolation and data transmission by utilizing a shape function three-dimensional space point interpolation method written by Fortran, and the results are output according to a given format for computational analysis of the structural load. The obtained calculation result can provide feedback information for the subsequent optimization design of the airplane structure and the aerodynamic shape.
Fig. 11 shows a schematic diagram of the pneumatic load extraction process and method, and it can be seen that the extraction method mainly has two inputs, which are the result of numerical calculation and the set of spatial discrete point data based on the pneumatic profile. For the same aircraft geometric configuration, the pneumatic load extraction work of all states can be finished only by generating a space discrete point data set once. Moreover, if the pneumatic appearance is locally changed in the later design process, only the spatial discrete point data of the related components need to be updated. In conclusion, the load extraction method provided by the invention has high universality, can quickly and efficiently finish the extraction work of mass pneumatic load data, and can greatly improve the efficiency of pneumatic and structural comprehensive iterative design.
It should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: modifications to the above-described embodiments are possible, or equivalents may be substituted for some of the features of the embodiments described above, and such modifications or substitutions are intended to be included within the scope of the present invention.
TABLE 1
Claims (4)
1. A complex airplane configuration aerodynamic load batch extraction method is characterized by comprising the following steps:
step 1: carrying out space discretization processing on the three-dimensional pneumatic shape of the unmanned aerial vehicle with a complex configuration to form an available space discrete point data set;
step 2: the numerical simulation calculation under different control plane deflection angles and different flight states at high and low speeds is completed to obtain corresponding object plane pressure distribution results stored in a PLOT3D format, and the numerical simulation calculation method comprises the following substeps:
step 2.1: dividing a structured computing grid aiming at different high and low speed configurations;
step 2.2: carrying out large-scale calculation analysis by using a computational fluid dynamics solver to obtain object plane aerodynamic load results in PLOT3D format in all states;
and step 3: a three-dimensional shape function space point interpolation method is compiled by adopting Fortran language, based on a space discrete point data set, a pressure coefficient result on each discrete point is extracted from an object plane result in a PLOT3D format by three-dimensional space point interpolation, and batch extraction work of pneumatic loads of all state numerical value calculation results is completed by cyclic interpolation calculation, and the method comprises the following substeps:
step 3.1: preparing an input file of a program, wherein the input file comprises a path stored by each PLOT3D format calculation result and corresponding state variables, including Mach number, flight altitude, attack angle, sideslip angle and each control surface deflection angle;
step 3.2: reading the object plane pneumatic load calculation result and the state variable in a PLOT3D format by utilizing a Fortran language writing program, and storing all object plane point coordinates and corresponding pneumatic loads as an array as an interpolation data source;
step 3.3: sequentially reading in the spatial discrete point data set coordinate matrix formed in the step 1 in an array form by using a Fortran language;
step 3.4: establishing a high-precision shape function three-dimensional space point interpolation method by using a Fortran language writing program;
step 3.5: circularly performing the step 3.2 to the step 3.4 until the interpolation extraction work of the object surface pneumatic load under all the states is completed;
and 4, step 4: and (3) exporting the pneumatic load data according to a format in a space discrete point data set by utilizing a Fortran language writing program, so that the object plane pneumatic load result in a PLOT3D format is changed into the pneumatic load data stored in an array format.
2. The method for batch extraction of aerodynamic loads of complex aircraft configuration according to claim 1, wherein the step 1 comprises the following substeps:
step 1.1: the whole airplane is divided into 11 types of airframes, central connecting sections, nacelles, hangers, wings, horizontal tails, vertical tails, flaps, ailerons, elevators, rudders and the like, and the total number of the parts is 25;
step 1.2: selecting respective space discrete profiles and discrete point numbers for each type of components according to the value ranges given in the table 1;
step 1.3: carrying out discretization processing on the pneumatic appearance of each part according to the given section and the number of discrete points of each part;
step 1.4: and respectively deriving the three-dimensional space coordinate data of all the points by using the components as distinctions to form a space discrete point data set.
3. The method for batch extraction of aerodynamic loads of complex aircraft configurations as claimed in claim 2, wherein the specific principle selected in the step 1.2 is as follows: given enough profiles and discrete points to better represent the true aerodynamic profile of the part, too many profiles and discrete points can result in an overall computationally expensive process.
4. The method for batch extraction of aerodynamic loads of complex aircraft configuration according to claim 2, wherein in step 1.4, all data are divided into P data matrices, and each matrix comprises NiA data column, each data column having MiAnd (4) grouping the three-dimensional point data. Wherein P represents the number of parts, NiRepresenting the number of discrete wire frames, M, corresponding to a componentiThe number of discrete points in each line frame is shown, xj, yj, zj (j is 1,2, … M)i) The three-dimensional coordinates of the spatial point. The spatial discrete point data set is composed of P Ni×MiAnd (i ═ 1,2, … P) in the data matrix. For the fuselage component in this example, its discrete point data set contains 50 x 50 spatial points, which are used to describe its three-dimensional shape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011178100.5A CN112287455A (en) | 2020-10-29 | 2020-10-29 | Method for batch extraction of pneumatic loads of complex aircraft configuration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011178100.5A CN112287455A (en) | 2020-10-29 | 2020-10-29 | Method for batch extraction of pneumatic loads of complex aircraft configuration |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112287455A true CN112287455A (en) | 2021-01-29 |
Family
ID=74372710
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011178100.5A Pending CN112287455A (en) | 2020-10-29 | 2020-10-29 | Method for batch extraction of pneumatic loads of complex aircraft configuration |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112287455A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102012953A (en) * | 2010-11-04 | 2011-04-13 | 西北工业大学 | CFD (computational fluid dynamics)/CSD (circuit switch data) coupled solving nonlinear aeroelasticity simulation method |
| US20130191087A1 (en) * | 2011-10-28 | 2013-07-25 | Airbus Operations Sas | Method of calculating dynamic pressure at the level of an aircraft surface |
| CN105205293A (en) * | 2015-11-05 | 2015-12-30 | 中国商用飞机有限责任公司 | Method and system for acquiring aerodynamic load of aircraft component |
| US20160011073A1 (en) * | 2013-12-05 | 2016-01-14 | The Boeing Company | Load Estimation System for Aerodynamic Structures |
| CN109325279A (en) * | 2018-09-10 | 2019-02-12 | 中国航发北京航空材料研究院 | A kind of method of discrete aircraft aerodynamic loading parametrization |
| CN109711048A (en) * | 2018-12-26 | 2019-05-03 | 北京航空航天大学 | It is a kind of to consider pneumatic and structure polymorphic type design variable Wing design method |
| CN109918694A (en) * | 2018-11-12 | 2019-06-21 | 中航通飞研究院有限公司 | A kind of Aircraft Load calculation method based on discretization load model |
-
2020
- 2020-10-29 CN CN202011178100.5A patent/CN112287455A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102012953A (en) * | 2010-11-04 | 2011-04-13 | 西北工业大学 | CFD (computational fluid dynamics)/CSD (circuit switch data) coupled solving nonlinear aeroelasticity simulation method |
| US20130191087A1 (en) * | 2011-10-28 | 2013-07-25 | Airbus Operations Sas | Method of calculating dynamic pressure at the level of an aircraft surface |
| US20160011073A1 (en) * | 2013-12-05 | 2016-01-14 | The Boeing Company | Load Estimation System for Aerodynamic Structures |
| CN105205293A (en) * | 2015-11-05 | 2015-12-30 | 中国商用飞机有限责任公司 | Method and system for acquiring aerodynamic load of aircraft component |
| CN109325279A (en) * | 2018-09-10 | 2019-02-12 | 中国航发北京航空材料研究院 | A kind of method of discrete aircraft aerodynamic loading parametrization |
| CN109918694A (en) * | 2018-11-12 | 2019-06-21 | 中航通飞研究院有限公司 | A kind of Aircraft Load calculation method based on discretization load model |
| CN109711048A (en) * | 2018-12-26 | 2019-05-03 | 北京航空航天大学 | It is a kind of to consider pneumatic and structure polymorphic type design variable Wing design method |
Non-Patent Citations (4)
| Title |
|---|
| 仓宇: "混合翼身融合构型飞行器气动外形一体化设计与优化", 中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑, pages 031 - 114 * |
| 任碧宁, 白文, 朱培烨, 周天孝: "开放式气动力数值模拟系统研究", 航空学报, no. 06, pages 481 - 484 * |
| 王骥飞: "高超声速飞行器气动外形一体化设计方法研究", 中国博士学位论文全文数据库 工程科技Ⅱ辑, pages 031 - 29 * |
| 韩鹏，刘晓晨，胡赞远，闫中午: "一种用于获得飞机部件气动载荷的网格向量法", 空气动力学学报, vol. 36, no. 4, pages 571 - 576 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109711048B (en) | Wing design method considering aerodynamic and structural multi-type design variables | |
| CN110704953B (en) | Analysis method for design sensitivity of static air elastic energy of high-aspect-ratio wing | |
| Sobieczky et al. | Supercritical airfoil and wing design | |
| Burdette et al. | Aerostructural design optimization of an adaptive morphing trailing edge wing | |
| CN109902359A (en) | The housing construction optimum design method of unmanned plane race, Flying-wing | |
| Barabanov et al. | Substantiation of choosing rational appearance of nose of aircraft with the use of mathematical modeling | |
| CN109977526B (en) | Method for adjusting finite element model of wing based on three-dimensional CST technology | |
| CN115358001A (en) | Aerodynamic stealth comprehensive optimization method for front edge radius of flying wing layout aircraft | |
| Lane et al. | A surface parameterization method for airfoil optimization and high lift 2D geometries utilizing the CST methodology | |
| CN114154434A (en) | Multi-constraint refined pneumatic optimization design method for layout of tailless flying wing | |
| Woodward | USSAERO computer program development, versions B and C | |
| Ronzheimer et al. | Aircraft wing optimization using high fidelity closely coupled CFD and CSM methods | |
| CN112287455A (en) | Method for batch extraction of pneumatic loads of complex aircraft configuration | |
| Bernstein et al. | Fast aerodynamic model for design technology | |
| Ishikawa et al. | Natural laminar flow Wing design for a low-boom supersonic aircraft | |
| Brooks et al. | UCRM: an aerostructural model for the study of flexible transonic aircraft wings | |
| Wang et al. | Static aeroelastic analysis of flexible aircraft with large deformations | |
| Joe et al. | Rapid generation of parametric aircraft structural models | |
| Anemaat et al. | Geometry design assistant for airplane preliminary design | |
| CN112711810A (en) | Method for processing gusty dynamic load file | |
| Long et al. | Multi-objective multidisciplinary optimization of long-endurance UAV wing using surrogate model in modelcenter | |
| Ronzheimer | Aircraft geometry parameterization with high-end CAD-software for design optimization | |
| Taylor et al. | The NASA Common Research Model: a Geometry-Handling Perspective | |
| CN113536458B (en) | Quick geometric modeling method of deformable wing based on class shape function transformation | |
| Voß | Comparison between VLM and CFD maneuver loads calculation at the example of a flying wing configuration |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |