Curved surface modeling method and system for distributed exhaust nozzle

Abstract

The invention provides a curved surface modeling method and system for a distributed exhaust nozzle, and belongs to the field of aerospace. The problem that an existing common nozzle modeling method is not suitable for compact and multi-mode aero-engines is solved. The method comprises the steps of obtaining various parameters of the exhaust nozzle; the contraction curved surface of the exhaust nozzle is divided into a circumferential contraction curved surface and a radial contraction curved surface; according to inlet and outlet constraint conditions, axial length and fluid dynamic characteristics of the distributed shrinkage nozzle, a Vickers curve is applied to obtain a design point of minimum flow loss, and a Vickers curve of a circumferential shrinkage curved surface is obtained; selecting Bezier curved surface control points according to the Vickers curve of the circumferential contraction curved surface; the Bezier curved surface is determined according to the Bezier curved surface control points; and carrying out topological optimization on the Bezier contraction curved surface to obtain a final model structure. The nozzle is mainly used in the nozzle design field.

Description

Technical Field

[0001] The invention belongs to the field of aerospace, and in particular relates to a surface modeling method for a distributed tail nozzle. Background Art

[0002] The tailpipe is a crucial component of an aircraft engine. It not only plays a central role in flight performance but also significantly impacts noise control, environmental pollution reduction, and engine efficiency. The tailpipe's design directly impacts the engine's thrust output, airflow control, and cooling system effectiveness, ultimately determining the overall performance and safety of the aircraft.

[0003] First, the tail nozzle accelerates airflow and effectively controls thrust direction, enabling the aircraft to better adapt to various flight conditions. The tail nozzle's design goal is not only to provide optimal thrust output but also to ensure engine durability, especially structural stability in high-temperature environments. Therefore, the tail nozzle's cooling system must have sufficient capacity to prevent overheating and damage to the engine's core components.

[0004] Currently, there are several common tail nozzle types, each designed and optimized for different application scenarios and performance requirements. The most common type is the circular nozzle, which has a relatively simple structure and is commonly found in turbojets and turbofan engines. The circular nozzle design allows airflow to pass smoothly and be accelerated to high speeds, making it suitable for aircraft such as civil airliners that require stable flight performance.

[0005] In addition, the adjustable nozzle is a very important design, which is widely used in fighter jets. By changing the shape of the inner wall of the nozzle, the adjustable nozzle can adjust the nozzle area, thereby controlling the speed and direction of the jet. This type of nozzle can adjust the thrust according to different flight conditions, improving the maneuverability and performance of the aircraft, especially in high-speed and supersonic flight. The vector nozzle is a more advanced design that allows the exhaust direction of the nozzle to be adjusted, thereby achieving precise control of the aircraft's pitch, yaw and roll. The design of the vector nozzle is usually found in fighter jets and vertical take-off and landing aircraft, and can provide higher flight control accuracy and flexibility.

[0006] Furthermore, the design of low-noise nozzles is a major innovation in the modern aviation industry, specifically designed to reduce engine noise pollution. With increasing environmental protection requirements, many commercial aircraft are increasingly focusing on noise control in their designs. Low-noise nozzles can reduce engine noise by optimizing airflow discharge, meeting the operational needs of civil airliners at urban airports and on busy routes.

[0007] However, traditional tail nozzle design methods are often no longer suitable for the specialized requirements of compact, multi-mode aircraft engines. These engines are designed to maximize space efficiency and adaptability across multiple flight modes. These engines integrate multiple propulsion methods to deliver optimal performance under varying flight conditions. However, due to limited space and numerous components, traditional tail nozzle designs cannot meet these requirements, especially when a fully retractable design is not feasible. Distributed tail nozzle design is crucial to addressing this issue. Summary of the Invention

[0008] In view of this, the present invention aims to propose a surface modeling method and system for a distributed tail nozzle, so as to solve the problem that the current common nozzle modeling methods are not suitable for compact, multi-mode aircraft engines.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a method for curved surface modeling of a distributed tail nozzle, the method comprising:

[0010] Step S1: Obtain various parameters of the tail nozzle, including: nozzle inlet and outlet dimensions, nozzle coverage angle range, nozzle length, and flow rate;

[0011] Step S2: dividing the contraction surface of the tail nozzle into a circumferential contraction surface and a radial contraction surface;

[0012] Step S3: Based on the inlet and outlet constraints, axial length, and fluid dynamic characteristics of the distributed convergent nozzle, the Vickers curve is applied to obtain the design point with minimum flow loss, and the Vickers curve of the circumferential convergent surface is obtained;

[0013] Step S4: selecting Bezier surface control points according to the Vickers curve of the circumferential contraction surface;

[0014] Step S5: determining the Bezier surface according to the Bezier surface control points;

[0015] Step S6: Perform topology optimization on the Bezier shrinkage surface to obtain the final model structure.

[0016] Furthermore, a preferred embodiment is proposed, wherein step S2 further comprises: decomposing the circumferential contraction surface into a plurality of planes along the radial direction, and decomposing the radial contraction surface into a plurality of planes along the circumferential direction.

[0017] Furthermore, a preferred embodiment is proposed, in which the Vickers curve in step S3 is:

[0018]

[0019] Among them, r is the circumferential offset distance corresponding to the design horizontal coordinate, rt is the tail nozzle outlet size, l1 is the tail nozzle length, l1 is the tail nozzle length, C=(r 0 / r t ) 2 , r0 is the inlet size of the tail nozzle, and x is the horizontal coordinate.

[0020] Furthermore, a preferred embodiment is proposed, wherein step S4 includes:

[0021] After obtaining the Vickers curve of the circumferential contraction surface, the corresponding plane equation is determined at each radial position, the curve is divided into five equal parts along the axial direction, and points are selected at the same axial position to finally obtain 8×5 control points;

[0022] For the radial contraction surface, the Vickers curve of the five planes decomposed along the circumferential direction is used to select the reference curve. The curve is divided into three equal parts in the axial direction, and points are selected at the same axial position to finally obtain 5×3 control points.

[0023] Furthermore, a preferred embodiment is proposed, wherein step S5 includes:

[0024]

[0025] Among them, S(u,v) is a point on the surface, u and v are the parameters of the surface, and P ij is the control point, B i,m (u) and B j,n (v) is the Bezier basis function, i is the index in the u direction, and j is the index in the v direction.

[0026] Furthermore, a preferred method is proposed, in which step S6 includes: maximizing the fluid dynamics performance of the tail nozzle and achieving the goal of minimizing flow losses by adjusting the positions of the control points and optimizing the shape of the curved surface.

[0027] Based on the same inventive concept, the present invention also proposes a surface shaping system for a distributed tail nozzle, the system comprising:

[0028] The parameter acquisition unit is used to obtain various parameters of the tail nozzle, including: the inlet and outlet dimensions of the nozzle, the coverage angle range of the nozzle, the length of the nozzle, and the flow rate;

[0029] A contraction surface classification unit is used to divide the contraction surface of the tail nozzle into a circumferential contraction surface and a radial contraction surface;

[0030] A Vickers curve acquisition unit for a circumferentially convergent surface is used to apply the Vickers curve to obtain a design point with minimum flow loss based on inlet and outlet constraints, axial length, and fluid dynamics characteristics of the distributed convergent nozzle, thereby acquiring the Vickers curve of the circumferentially convergent surface;

[0031] A Bezier surface control point acquisition unit, used for selecting Bezier surface control points according to the Vickers curve of the circumferential contraction surface;

[0032] A Bezier surface acquisition unit, used for determining a Bezier surface according to Bezier surface control points;

[0033] The topology optimization unit is used to perform topology optimization on the Bezier shrinkage surface to obtain the final model structure.

[0034] Based on the same inventive concept, the present invention also proposes a computer device, including a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a surface modeling method for a distributed tail nozzle according to any one of the above items.

[0035] Based on the same inventive concept, the present invention also proposes a computer-readable storage medium, which stores a computer program. When the computer program is run by a processor, it executes the steps of the surface modeling method of a distributed tail nozzle as described in any one of the above.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] This invention proposes a surface modeling method for distributed tail nozzles, particularly suitable for compact and multi-mode aircraft engines. Traditional nozzle design methods are generally unsuitable for the space and performance requirements of such engines. However, through the surface modeling of distributed tail nozzles, this invention enables more precise and efficient nozzle design within limited space, meeting the requirements of different operating modes. By applying Vickers curves to optimize the design of the circumferentially converging surface, this method can effectively reduce flow losses. During nozzle design, flow losses directly affect engine efficiency and performance. By minimizing flow losses and optimizing the aerodynamic performance of the nozzle, the overall nozzle efficiency and engine thrust output are improved. Using Bezier surface control points to precisely design the tail nozzle surface enables high-precision control of the nozzle surface shape. This is particularly important for nozzles requiring highly accurate geometry, especially in different modes. A refined surface design ensures smoother airflow through the nozzle, reducing unnecessary turbulence and drag. By topologically optimizing the Bezier surface, this method not only considers fluid performance but also enhances the structural strength and stability of the nozzle. Topology optimization can improve the structural design of the nozzle while ensuring fluid dynamics performance, making it more adaptable to different working conditions and operating conditions, and improving the reliability and durability of the nozzle.

[0038] The present invention proposes a surface modeling method for a distributed tail nozzle. By rationally dividing the contraction surface into circumferential and radial surfaces, combined with fluid dynamic characteristics and topological optimization, the tail nozzle can be designed quickly and efficiently. This systematic design process helps improve design efficiency, reduce manual intervention and debugging time, and accelerate the development process of aircraft engine nozzles. Nozzle design needs to take into account the different requirements under multiple operating modes. Through distributed design and fine optimization, the present invention enables the nozzle to adapt to different injection states, such as high and low speeds, and different thrust requirements, thereby improving the overall performance of the engine.

[0039] The method proposed in the present invention is not only applicable to nozzle design in the aerospace field, but can also be applied to other fields involving circumferentially contracting surfaces, such as fluid conveying pipelines, chemical equipment, etc., and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 This is a schematic diagram of the distributed convergent tail nozzle structure according to the first embodiment, wherein 1 represents the inlet of the distributed nozzle, 2 represents the inlet constraint of the distributed nozzle, 3 represents the outlet of the distributed nozzle, 4 represents the outlet constraint of the distributed nozzle, 5 represents the circumferential surface of the distributed nozzle, and 6 represents the radial convergent surface of the distributed nozzle;

[0042] Figure 2 This is a schematic diagram of a plane that equally divides the distributed tail nozzle according to the tenth embodiment along the radial and circumferential directions, wherein: Figure 2 (a) is a schematic diagram of a plane divided equally along the radial direction. Figure 2 (b) is a schematic diagram of a plane divided equally along the circumferential direction;

[0043] Figure 3 is the wall cross section of one side of the distributed tail nozzle at a certain radial and circumferential position described in the tenth embodiment, wherein: Figure 3 (a) is a schematic diagram of a radial cross section. Figure 3 (b) is a schematic diagram of a circumferential cross section;

[0044] Figure 4 This is the Bezier surface control point distribution diagram described in the tenth embodiment, wherein: Figure 4 (a) is a schematic diagram of the control points of the circumferential contraction surface. Figure 4 (b) is a schematic diagram of the control points of the radial contraction surface, and 7 and 8 represent the Bezier surface control points on the circumferential and radial contraction surfaces, respectively. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features therein can be combined with each other in the absence of conflict, and the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0046] Implementation method 1, see Figure 1 This embodiment describes a method for curved surface modeling of a distributed tail nozzle, the method comprising:

[0047] Step S1: Obtain various parameters of the tail nozzle, including: nozzle inlet and outlet dimensions, nozzle coverage angle range, nozzle length, and flow rate;

[0048] Step S2: dividing the contraction surface of the tail nozzle into a circumferential contraction surface and a radial contraction surface;

[0049] Step S3: Based on the inlet and outlet constraints, axial length, and fluid dynamic characteristics of the distributed convergent nozzle, the Vickers curve is applied to obtain the design point with minimum flow loss, and the Vickers curve of the circumferential convergent surface is obtained;

[0050] Step S4: selecting Bezier surface control points according to the Vickers curve of the circumferential contraction surface;

[0051] Step S5: determining the Bezier surface according to the Bezier surface control points;

[0052] Step S6: Perform topology optimization on the Bezier shrinkage surface to obtain the final model structure.

[0053] The method proposed in this embodiment is particularly suitable for compact and multi-mode aircraft engines. Traditional nozzle design methods are generally not adapted to the space and performance requirements of such engines. However, this embodiment, through the curved surface modeling of the distributed tail nozzle, can achieve more precise and efficient nozzle design within a limited space, meeting the requirements of different operating modes. By applying the Vickers curve to optimize the design of the circumferential convergence surface, this method can effectively reduce flow losses. During the nozzle design process, flow losses directly affect the efficiency and performance of the engine. By minimizing flow losses and optimizing the aerodynamic performance of the nozzle, the overall nozzle efficiency and engine thrust output are improved. Using Bezier surface control points to precisely design the tail nozzle surface enables high-precision nozzle surface shape control. This is particularly important for nozzles that require highly accurate geometry, especially in different modes. A refined surface design ensures smoother airflow through the nozzle, reducing unnecessary turbulence and drag. By topologically optimizing the Bezier surface, this method not only considers fluid performance but also enhances the structural strength and stability of the nozzle. Topology optimization can improve the structural design of the nozzle while ensuring fluid dynamics performance, making it more adaptable to different working conditions and operating conditions, and improving the reliability and durability of the nozzle.

[0054] The method proposed in this embodiment rationally divides the contracting surface into circumferential and radial surfaces, combines fluid dynamics characteristics with topology optimization, and can quickly and efficiently design the tail nozzle. This systematic design process helps improve design efficiency, reduce manual intervention and debugging time, and accelerate the development process of aircraft engine nozzles. Nozzle design needs to take into account the different requirements of multiple operating modes. In this embodiment, through distributed design and fine optimization, the nozzle can adapt to different injection states, such as high and low speeds, and different thrust requirements, thereby improving the overall performance of the engine.

[0055] Implementation method 2. This implementation method further limits the surface modeling method of a distributed tail nozzle described in implementation method 1, and step S2 also includes: decomposing the circumferential contraction surface into several planes along the radial direction, and decomposing the radial contraction surface into several planes along the circumferential direction.

[0056] In this implementation, decomposing the circumferentially converging surface into several planes along the radial direction and the radially converging surface into several planes along the circumferential direction facilitates more accurate modeling of the complex curved surface structure of the distributed tail nozzle. This decomposition method effectively captures the shape changes of the tail nozzle in different directions, ensuring higher modeling accuracy.

[0057] By decomposing a surface into several planes, complex surface problems can be transformed into calculations between multiple planes. This not only simplifies the surface modeling process but also reduces computational complexity, thereby improving computational efficiency. This method can effectively reduce processing difficulty, especially when computing resources are limited.

[0058] Implementation method 3: This implementation method further limits the surface modeling method of a distributed tail nozzle described in implementation method 1. The Vickers curve in step S3 is:

[0059]

[0060] Among them, r is the circumferential offset distance corresponding to the design horizontal coordinate, r t is the tail nozzle outlet size, l1 is the tail nozzle length, l1 is the tail nozzle length, C=(r 0 / r t ) 2 , r0 is the inlet size of the tail nozzle, and x is the horizontal coordinate.

[0061] In this embodiment, the Vickers curve accurately describes the geometric changes of the tail nozzle along the design axis through the relationship between the horizontal coordinate x and the circumferential offset r. According to the design requirements, the circumferential offset at different positions is precisely controlled to ensure the flow efficiency and stability of the jet. Furthermore, the shape of the curved surface is defined according to the inlet and outlet dimensions of the tail nozzle and the length of the tail nozzle, so that the design of the curved surface is more in line with actual engineering requirements. The flexibility of the Vickers curve allows for independent design and adjustment according to different areas of the nozzle (inlet and outlet), thereby optimizing the path and streamlines of the airflow through the tail nozzle.

[0062] Embodiment 4: This embodiment further limits the surface modeling method of a distributed tail nozzle described in embodiment 1. Step S4 includes:

[0063] After obtaining the Vickers curve of the circumferential contraction surface, the corresponding plane equation is determined at each radial position, the curve is divided into five equal parts along the axial direction, and points are selected at the same axial position to finally obtain 8×5 control points;

[0064] For the radial contraction surface, the Vickers curve of the five planes decomposed along the circumferential direction is used to select the reference curve. The curve is divided into three equal parts in the axial direction, and points are selected at the same axial position to finally obtain 5×3 control points.

[0065] In this embodiment, the control points of the curved surface are not only divided according to the radial and circumferential contraction curves, but the distribution of control points is also refined by equally dividing the curve in the axial direction. By adjusting the shape of the tail nozzle curved surface, the geometric characteristics of the surface at different locations meet the design requirements.

[0066] In this implementation, by decomposing and processing the Vickers curve separately in the circumferential and radial directions, designers can optimize the curved surfaces in different directions based on the specific geometric requirements of the tail nozzle. This distributed approach helps flexibly address the complex geometric variations that may occur in actual tail nozzle applications and meet diverse design needs.

[0067] This method simplifies the surface calculation process by bisecting the curve and selecting corresponding points at each axial position. It also optimizes control points in the axial, radial, and circumferential directions, avoiding overly complex calculations and improving computational efficiency. This method is suitable for engineering designs that require rapid generation of complex geometric shapes, saving time and computing resources.

[0068] In this embodiment, by selecting points at multiple axial positions, the smoothness and accuracy of the tail nozzle surface are ensured. In particular, when performing segmented processing in the axial and radial directions, geometric errors caused by uneven distribution of control points can be avoided, thereby improving the design accuracy of the tail nozzle.

[0069] Embodiment 5: This embodiment further limits the surface modeling method of a distributed tail nozzle described in embodiment 1. Step S5 includes:

[0070]

[0071] Among them, S(u,v) is a point on the surface, u and v are the parameters of the surface, and P ij is the control point, B i,m (u) and B j,n (v) is the Bezier basis function, which is used to control the linear combination of points to define the shape of the surface, i is the index in the u direction, and j is the index in the v direction.

[0072] This implementation uses Bezier surface control points and Bezier basis functions to provide very precise control over the surface shape. By selecting control points, the curvature, smoothness, and other geometric features of the surface can be flexibly adjusted, enabling highly customized tailpipe surface design.

[0073] Implementation method six: This implementation method further limits the surface modeling method of a distributed tail nozzle described in implementation method one. Step S6 includes: ensuring the maximization of the tail nozzle fluid dynamics performance and achieving the goal of minimum flow loss by adjusting the control point position and optimizing the shape of the surface.

[0074] By adjusting the position of control points and optimizing the curved surface shape, the nozzle's airflow path can be precisely adjusted, ensuring better guidance and smoothness of the airflow as it passes through the nozzle. This not only helps reduce unnecessary turbulence but also reduces flow resistance, thereby improving the nozzle's overall performance. Optimizing the nozzle's curved surface shape helps minimize energy losses in the flow. By reducing irregularities and vortices in the flow, air resistance is reduced, further improving the nozzle's efficiency. Reduced flow losses directly improve the aircraft's fuel efficiency and speed.

[0075] Embodiment 7: A distributed tail nozzle curved surface shaping system according to this embodiment includes:

[0076] The parameter acquisition unit is used to obtain various parameters of the tail nozzle, including: the inlet and outlet dimensions of the nozzle, the coverage angle range of the nozzle, the length of the nozzle, and the flow rate;

[0077] A contraction surface classification unit is used to divide the contraction surface of the tail nozzle into a circumferential contraction surface and a radial contraction surface;

[0078] A Vickers curve acquisition unit for a circumferentially convergent surface is used to apply the Vickers curve to obtain a design point with minimum flow loss based on inlet and outlet constraints, axial length, and fluid dynamics characteristics of the distributed convergent nozzle, thereby acquiring the Vickers curve of the circumferentially convergent surface;

[0079] A Bezier surface control point acquisition unit, used for selecting Bezier surface control points according to the Vickers curve of the circumferential contraction surface;

[0080] A Bezier surface acquisition unit, used for determining a Bezier surface according to Bezier surface control points;

[0081] The topology optimization unit is used to perform topology optimization on the Bezier shrinkage surface to obtain the final model structure.

[0082] Embodiment 8. A computer device described in this embodiment includes a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a surface modeling method for a distributed tail nozzle described in any one of embodiments 1 to 6.

[0083] Implementation method nine: A computer-readable storage medium described in this implementation method stores a computer program, and when the computer program is executed by a processor, the steps of a surface modeling method for a distributed tail nozzle as described in any one of implementation methods one to six are executed.

[0084] Implementation Method 10: See Figures 2 to 4This embodiment provides a specific example of the surface modeling method of a distributed tail nozzle described in embodiment 1, and is also used to explain embodiments 2 to 6. Specifically:

[0085] The purpose of this embodiment is to provide a method for shaping the convergence curve of a distributed tail nozzle, which can accurately control the convergence characteristics of the tail nozzle, optimize the flow of air in the nozzle, improve the propulsion efficiency and thrust of the engine, and enhance the adaptability of the tail nozzle to variable working conditions, thereby improving the flight performance and stability of the aircraft. The convergence dimensions of the distributed tail nozzle include:

[0086] (1) One-dimensional design of distributed nozzle: According to the actual application scenario, determine the inlet and outlet dimensions of the circumferentially convergent nozzle, the coverage angle range of the distributed nozzle, the nozzle length, the flow rate, and other related geometric constraints.

[0087] (2) The contraction surface of the distributed tail nozzle is divided into a circumferential contraction surface and a radial contraction surface: First, the circumferential contraction surface is decomposed into 8 planes along the radial direction. These planes are evenly distributed along the radial direction, such as Figure 2 (a); then decompose the radial contraction surface into 5 planes along the circumference, and these planes are evenly distributed along the circumference, as shown in Figure 2 (b) shown.

[0088] (3) At each radial and circumferential position, based on the inlet and outlet constraints and axial length of the distributed convergent nozzle, combined with the Vickers curve, several points with minimum flow loss can be obtained. The formula of the Vickers curve is:

[0089]

[0090] Among them, r0 is the inlet size of the tail nozzle, r t is the tail nozzle outlet size, l1 is the tail nozzle length, C=(r 0 / r t ) 2 , x is the horizontal coordinate, and r is the circumferential offset distance corresponding to the designed horizontal coordinate.

[0091] (4) Selection of Bezier surface control points: When defining a Bezier surface, a set of control points is usually used to describe the shape of the surface. For the selection of control points for the circumferential contraction surface, the equations of the planes obtained at 8 different radial positions on the circumferential contraction surface are determined. The obtained Vickers curve is divided into 5 equal parts along the axial direction, and points are taken at the same axial position to obtain 8 points on 8 planes, and finally 8*5 control points are obtained, such as Figure 4(a); Similarly, for the selection of control points on the radial contraction surface, the Vickers curves of each plane obtained at 5 different circumferential positions on the radial contraction surface are used as the basis, the obtained Vickers curve is divided into 3 equal parts along the axial direction, and points are taken at the same axial position to obtain 5 points on 5 planes, and finally 5*3 control points are obtained, as shown in FIG. Figure 4 (b) shown.

[0092] (5) Determination of Bezier surface: The 8*5 and 5*3 points obtained from the above circumferential contraction surface and radial contraction surface are used as the control points of the circumferential Bezier contraction surface and radial Bezier contraction surface respectively, combined with the expression of the Bezier surface:

[0093]

[0094] Among them, S(u,v) is a point on the surface, u and v are the parameters of the surface, and P ij is the control point, B i,m (u) and B j,n (v) is the Bezier basis function, which is used to define the shape of the surface by the linear combination of control points. i and j are the indices in the u and v directions respectively. The circumferential and radial contraction surfaces of the distributed tail nozzle can be obtained.

[0095] (6) The final model structure can be obtained by topologically optimizing the obtained radial and circumferential Bezier shrinkage surfaces.

[0096] The present invention proposes a modeling method for a distributed tail nozzle contraction surface. The above design method can achieve the following effects:

[0097] By dividing the circumferential contraction surface and the radial contraction surface and taking points, the control points of the Bezier surface are obtained. These control points can be used to more accurately describe the shapes of the circumferential contraction surface and the radial contraction surface.

[0098] Accurate calculation methods for circumferential and radial contraction surfaces help to more accurately predict the flow characteristics of the airflow in the nozzle during the nozzle design process, reduce phenomena such as separation zones that increase flow losses, and improve the thrust and efficiency of the engine.

[0099] Those skilled in the art will appreciate that embodiments of the present disclosure may be provided as methods, systems, or computer program products. Thus, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0100] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including the instruction device, which implements the function specified in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0101] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and are not intended to limit its scope of protection. Although the present disclosure has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present disclosure, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the disclosed claims.

Claims

1. A surface modeling method for a distributed tail nozzle, characterized in that: The method comprises: Step S1: Obtain various parameters of the tail nozzle, including: nozzle inlet and outlet dimensions, nozzle coverage angle range, nozzle length, and flow rate; Step S2: dividing the contraction surface of the tail nozzle into a circumferential contraction surface and a radial contraction surface; Step S3: Based on the inlet and outlet constraints, axial length, and fluid dynamic characteristics of the distributed convergent nozzle, the Vickers curve is applied to obtain the design point with minimum flow loss, and the Vickers curve of the circumferential convergent surface is obtained; Step S4: selecting Bezier surface control points according to the Vickers curve of the circumferential contraction surface; Step S5: determining the Bezier surface according to the Bezier surface control points; Step S6: Perform topology optimization on the Bezier shrinkage surface to obtain the final model structure.

2. The method for curved surface modeling of a distributed tail nozzle according to claim 1, characterized in that: The step S2 further includes: decomposing the circumferential contraction curved surface into a plurality of planes along the radial direction, and decomposing the radial contraction curved surface into a plurality of planes along the circumferential direction.

3. The method for curved surface modeling of a distributed tail nozzle according to claim 1, characterized in that: The Vickers curve in step S3 is: Among them, r is the circumferential offset distance corresponding to the design horizontal coordinate, r t is the tail nozzle outlet size, l1 is the tail nozzle length, l1 is the tail nozzle length, C=(r0 / r t ) 2 , r0 is the inlet size of the tail nozzle, and x is the horizontal coordinate.

4. The method for curved surface modeling of a distributed tail nozzle according to claim 1, characterized in that: The step S4 comprises: After obtaining the Vickers curve of the circumferential contraction surface, the corresponding plane equation is determined at each radial position, the curve is divided into five equal parts along the axial direction, and points are selected at the same axial position to finally obtain 8×5 control points; For the radial contraction surface, the Vickers curve of the five planes decomposed along the circumferential direction is used to select the reference curve. The curve is divided into three equal parts in the axial direction, and points are selected at the same axial position to finally obtain 5×3 control points.

5. The method for curved surface modeling of a distributed tail nozzle according to claim 1, characterized in that: The step S5 comprises: Among them, S(u,v) is a point on the surface, u and v are the parameters of the surface, and P ij is the control point, B i,m (u) and B j,n (v) is the Bezier basis function, i is the index in the u direction, and j is the index in the v direction.

6. The method for curved surface modeling of a distributed tail nozzle according to claim 1, characterized in that: The step S6 includes: maximizing the fluid dynamics performance of the tail nozzle and achieving the goal of minimizing flow loss by adjusting the positions of the control points and optimizing the shape of the curved surface.

7. A surface modeling system for a distributed tail nozzle, characterized in that: The system comprises: The parameter acquisition unit is used to obtain various parameters of the tail nozzle, including: the inlet and outlet dimensions of the nozzle, the coverage angle range of the nozzle, the length of the nozzle, and the flow rate; A contraction surface classification unit is used to divide the contraction surface of the tail nozzle into a circumferential contraction surface and a radial contraction surface; A Vickers curve acquisition unit for a circumferentially convergent surface is used to apply the Vickers curve to obtain a design point with minimum flow loss based on inlet and outlet constraints, axial length, and fluid dynamics characteristics of the distributed convergent nozzle, thereby acquiring the Vickers curve of the circumferentially convergent surface; A Bezier surface control point acquisition unit, used for selecting Bezier surface control points according to the Vickers curve of the circumferential contraction surface; A Bezier surface acquisition unit, used for determining a Bezier surface according to Bezier surface control points; The topology optimization unit is used to perform topology optimization on the Bezier shrinkage surface to obtain the final model structure.

8. A computer device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a surface modeling method for a distributed tail nozzle according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the steps of a surface modeling method for a distributed tail nozzle according to any one of claims 1 to 6.

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