Parametric Modeling Method for Civil Aircraft Wings Based on CLASSA Surface

Abstract

The present invention discloses a parametric modeling method for a civil aircraft wing based on a Class A surface, comprising the following steps: S1, adjusting the airfoil of an existing civil aircraft with reference to the Class A surface design principles to obtain the wing surface; S2, using the civil aircraft model in S1 as a reference model, obtaining key parameters by reference data and reasonable calculation; S3, creating different cross-sections and guide lines based on the two-dimensional wing data, and obtaining a primary wing by sweeping the wing surface; S4, analyzing the primary wing using the zebra crossing inspection method and Gaussian curvature analysis method to evaluate the quality of the Class A surface; S5, adding winglets to the primary wing to complete the civil aircraft wing design. Based on aircraft flight data parameters and Class A surface design, the present invention can design a wing with good aerodynamic performance and meeting Class A surface technology through parametric modeling.

Description

Technical Field

[0001] This invention relates to the field of civil aircraft wing parameter design technology, and in particular to a method for civil aircraft wing parameter modeling based on CLASS A surface. Background Technology

[0002] The design method of supercritical wings is very common in modern aircraft. After determining the aerodynamic layout requirements of the aircraft, the main wing parameters are also determined. The key to the C919's supercritical wing design is the comprehensive and high-precision optimization of the wing shape to improve aerodynamic efficiency. However, the surface of current civil aircraft wings has not yet reached ultra-high precision and ultra-smoothness, which means that the ability to uniformly integrate airflow still needs to be improved.

[0003] CLASS A surface reconstruction technology can be used to create highly complex, smooth, and precise surface models. This method is generally used in CAD and computer-aided drafting processes to generate the external surfaces of products such as automobiles, aircraft, and ships. Currently, CLASS A surfaces have not been applied to wing design. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for parametric modeling of civil aircraft wings based on CLASS A surfaces. Based on the aircraft flight data parameters and CLASS A surface design, a wing with good aerodynamic performance and meeting the requirements of CLASS A surface technology can be designed through parametric modeling.

[0005] The present invention solves the technical problem by adopting the following technical solution:

[0006] A method for modeling the parameters of a civil airliner wing based on a CLASS A surface includes the following steps:

[0007] S1. Based on the existing airfoil of a civil airliner, the airfoil is adjusted with reference to the CLASS A surface design principle to obtain the airfoil surface;

[0008] S2 uses the civil passenger aircraft model in S1 as a reference model, and obtains key parameters through reference data and reasonable calculations;

[0009] S3: Based on the two-dimensional data of the wing, different cross sections and guide lines are created, and the wing surface is swept to obtain the first-generation wing;

[0010] S4. The first-generation wing was analyzed using the zebra stripe inspection method and Gaussian curvature analysis method to evaluate the surface quality of CLASS A.

[0011] The S5 was developed by adding winglets to the first-generation wing, completing the design of the civil airliner wing.

[0012] Furthermore, key parameters in S2 include: root chord length, wingtip chord length, chord sweep angle, wingspan, and dihedral angle.

[0013] Furthermore, in S3, the specific method for obtaining the first-generation wing is as follows: Given the airfoil section lines and wing two-dimensional data, a design architecture with four control sections is used to construct the main body of the aircraft's aerodynamic shape, from the inside out: wing root control section, inner trailing edge turning control section, outer trailing edge turning control section, and outer wing control section. Subsequently, the data is adjusted and analyzed. Based on the trailing edge turning position, the proportions of the four wing surfaces are obtained, and the specific parameters of the four control sections are determined. Then, points at the leading edge of each wing section are selected and connected to form a guide line. The first-generation wing is obtained through a sweep function.

[0014] Furthermore, in S4, the first-generation wing was analyzed using the zebra stripe inspection method and Gaussian curvature analysis method. The specific methods for evaluating the quality of the CLASS A surface were as follows: After adjusting the light source direction, number of stripes, stripe width, and color conversion using the zebra stripe inspection method, it was observed that the zebra stripes were smooth and the transition was relatively rounded; through the Gaussian curvature analysis method, it was observed that the curvature of the entire wing surface was small, with a maximum value of only 0.000659 mm-1, and the transition was regular and stable, indicating that the quality of the CLASS A surface passed the acceptance test.

[0015] Furthermore, in S5, the method for creating winglets is as follows: Based on the first-generation wing, using the wing surface as a reference, and referring to the specific parameters of existing civil airliner winglets—tip root ratio, canard angle, and sweep angle—the specific parameters of the winglet tip surface are obtained; by creating a series of reference planes and reference normals, the winglet leading edge line is created; starting from the wingtip surface and using the winglet leading edge line as the sweep path, an endpoint surface with a ratio of 0.4 to the wingtip surface is set at the endpoint of the winglet leading edge line according to the tip root ratio; after clarifying the starting surface, endpoint surface, and sweep path, the winglet is created.

[0016] Furthermore, it also includes: S6, which uses Fluent to test the aerodynamic performance of a completed civil aircraft wing design.

[0017] The present invention discloses a method for modeling the parameters of a civil airliner wing based on a CLASS A surface, which has the following beneficial effects:

[0018] (1) For surface-based structural design, CLASS A surface is more suitable for the drag reduction characteristics of aircraft skin;

[0019] (2) The wing modeling method based on CLASS A surface is easier to implement than the traditional wing design method;

[0020] (3) Compared with the original wing surface, the passenger aircraft wing with CLASS A surface design has better aerodynamic performance in terms of airflow variation and more uniform pressure distribution. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention;

[0022] Figure 2 This is a schematic diagram of the wing surface of the present invention;

[0023] Figure 3 This is a two-dimensional data diagram of the wing of the present invention;

[0024] Figure 4 This is the initial wing design drawing for this invention;

[0025] Figure 5 This is a schematic diagram of the wing with winglets added according to the present invention;

[0026] Figure 6 This is a pressure cloud diagram of the wing of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] refer to Figure 1 This invention discloses a method for designing civil aircraft wings based on CLASS A surfaces. Based on the design principles of CLASS A surfaces, the method creates a wing surface using existing airfoil data. Then, by incorporating some existing wing structural parameters, the wing surface is swept along a design path to obtain a passenger aircraft wing that satisfies the CLASS A surface design. The design method includes the following steps:

[0029] S1, based on the existing BOEING 737 MIDSPAN AIRFOIL airfoil, the airfoil is adjusted with reference to the CLASS A surface design principle. A circular arc is used to connect the trailing edge transition, with a curvature of 0.085mm⁻¹, resulting in the airfoil surface, as shown below. Figure 2 As shown.

[0030] S2, referring to existing data of similar aircraft, obtains a two-dimensional data plane, such as... Figure 3As shown. This invention selects the Boeing 737 passenger aircraft, which is widely used in the current civil aviation market, as the reference model. The main reference data are: fuselage width, wingspan, wing root chord length, wingtip chord length, sweep angle, and dihedral angle. By using the reference data and making reasonable calculations, the length of a single wingspan is obtained using the wingspan and fuselage width, resulting in the following key parameters: wing root chord length 7880mm, wingtip chord length 1250mm, chord sweep angle 25.02°, single wingspan 15280mm, and dihedral angle 6°.

[0031] S3, based on the wing's 2D data, creates different sections and guide lines, and obtains the initial wing through sweeping. Given the obtained airfoil section lines and wing 2D data, a design architecture with four control sections is used to construct the main body of the aircraft's aerodynamic shape, from the inside out: wing root control section; inner trailing edge bend control section; outer trailing edge bend control section; and outer wing control section. Subsequent data adjustments and analysis determine the proportions of the four wing surfaces based on the trailing edge bend position, defining the specific parameters of the four control surfaces. Then, points on the leading edge of each wing section are selected and connected to form a guide line. The initial wing is then obtained through sweeping, as shown below. Figure 4 As shown. The wing is a crucial component of an aircraft, generating lift for flight. It typically consists of two airfoils, left and right, arranged symmetrically on either side of the fuselage. Draw a wing model based on existing wing designs.

[0032] S4. The quality of the CLASS A surface of the first-generation wing was evaluated using the zebra stripe inspection method and Gaussian curvature analysis. After adjusting the light source direction, number of stripes, stripe width, and color transition, the zebra stripe inspection showed smooth lines and a relatively rounded transition. Gaussian curvature analysis revealed a small curvature across the entire wing surface, with a maximum value of only 0.000659 mm⁻¹, and a smooth, regular transition, indicating that the CLASS A surface quality passed acceptance.

[0033] The S5, by adding winglets to the original wing, completed the design of the civil airliner wing, such as... Figure 5As shown. Based on the initial wing design, using the wing surface as a reference, and referencing and approximating the specific parameters of a certain passenger aircraft's winglet: a tip-to-root ratio of 0.4, an outward cant of 25°, and a sweep angle of 25°, the specific parameters of the winglet's tip surface are obtained. By creating a series of reference planes and reference normals, the leading edge line of the winglet with an outward cant of 25° and a sweep angle of 25° is created. Starting from the wingtip surface and using the winglet's leading edge line as the sweep path, an endpoint surface with a ratio of 0.4 to the wingtip surface is set at the endpoint of the winglet's leading edge line. After clarifying the starting surface, endpoint surface, and sweep path, the winglet is created using the sweep function in CATIA. A winglet is a device installed at the wingtip to improve airflow, increasing wing lift, reducing wing drag, and improving airflow conditions on the wing surface.

[0034] S6, using Fluent, conducted aerodynamic performance tests on the completed design of a civil airliner wing. This wind tunnel test analyzed the aircraft's aerodynamic shape during cruise at a low angle of attack. The test conditions were: speed 200 m / s, angle of attack 2°, ideal atmospheric conditions, and temperature 15°C. The convergence condition for this calculation was: when the residual is less than 10⁻³, lift and drag tend to stabilize. We can particularly observe that the changes in the three pressures from front to back are very uniform, such as... Figure 6 (a) Figure 6 (b) and Figure 6 As shown in (c), Figure 6 (a) shows the wing pressure cloud diagram under total pressure. Figure 6 (b) shows the wing pressure cloud diagram under medium dynamic pressure, such as Figure 6 (c) shows the pressure cloud diagram of the wing under static pressure, which clearly shows that the pressure distribution on the model surface is uniform and the transition is smooth.

[0035] This invention will design a wing with good aerodynamic performance and meet the requirements of CLASS A surface technology by parametric modeling based on passenger aircraft flight data parameters and CLASS A surface design. The feasibility and effectiveness of the design and optimization methods in this paper will be verified by wind tunnel experiments.

[0036] For surface-based structural design, CLASS A surfaces are better suited to the drag-reduction characteristics of aircraft skin; wing modeling based on CLASS A surfaces is easier to implement than traditional wing design methods; compared to traditional wing surfaces, passenger aircraft wings designed with CLASS A surfaces exhibit better aerodynamic performance in managing airflow changes and more uniform pressure distribution. The application of CLASS A surfaces in the aviation field has profound significance for improving aircraft performance, efficiency, and aesthetics. CLASS A surfaces will bring more innovation and breakthroughs to the aviation industry.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for modeling the parameters of a civil passenger aircraft wing based on a CLASS A surface, characterized in that, Includes the following steps: S1. Based on the existing airfoil of a civil airliner, the airfoil is adjusted with reference to the CLASS A curved surface design principle. The transition part at the trailing edge is connected by a circular arc with a curvature of 0.085mm-1, thus obtaining the airfoil surface. S2 uses the civil airliner model in S1 as a reference model. Key parameters are obtained through reference data and reasonable calculations, including: wing root chord length, wingtip chord length, chord sweep angle, single wingspan, and dihedral angle. S3: Based on the two-dimensional data of the wing, different cross sections and guide lines are created, and the wing surface is swept to obtain the first-generation wing; The specific method for obtaining the first-generation wing is as follows: Given the airfoil section lines and two-dimensional wing data, a design architecture with four control sections is used to construct the main body of the aircraft's aerodynamic shape, from the inside out: wing root control section, inner trailing edge turning control section, outer trailing edge turning control section, and outer wing control section. Subsequently, the data is adjusted and analyzed. Based on the trailing edge turning position, the proportions of the four wing surfaces are obtained, and the specific parameters of the four control sections are determined. Then, points on the leading edge of each wing section are selected and connected to form a guide line. The first-generation wing is obtained through a sweep function. S4. The first-generation wing was analyzed using the zebra stripe inspection method and Gaussian curvature analysis method to evaluate the surface quality of CLASS A. The S5 was developed by adding winglets to the first-generation wing, completing the design of the civil airliner wing.

2. The method for modeling civil aircraft wings based on CLASS A surfaces according to claim 1, characterized in that, In S4, the first-generation wing was analyzed using the zebra stripe inspection method and Gaussian curvature analysis method. The specific methods for evaluating the quality of the CLASS A surface were as follows: After adjusting the light source direction, number of stripes, stripe width, and color conversion using the zebra stripe inspection method, it was observed that the zebra stripes were smooth and the transition was relatively rounded; through the Gaussian curvature analysis method, it was observed that the curvature of the entire wing surface was small, with a maximum value of only 0.000659 mm-1, and the transition was regular and stable, indicating that the quality of the CLASS A surface passed the acceptance test.

3. The method for modeling civil aircraft wings based on CLASS A surfaces according to claim 2, characterized in that, In S5, the method for creating winglets is as follows: Based on the first-generation wing, using the wing surface as a reference, and referring to the specific parameters of existing civil airliner winglets—tip root ratio, canard angle, and sweep angle—the specific parameters of the winglet tip surface are obtained; by creating a series of reference planes and reference normals, the winglet leading edge line is created; starting from the wingtip surface and using the winglet leading edge line as the sweep path, an endpoint surface with a ratio of 0.4 to the wingtip surface is set at the endpoint of the winglet leading edge line according to the tip root ratio; after clarifying the starting surface, endpoint surface, and sweep path, the winglet is created.

4. The method for modeling civil aircraft wings based on CLASS A surfaces according to claim 3, characterized in that, Also includes: S6 uses Fluent to test the aerodynamic performance of a completed civil aircraft wing design.

Images