A design method, device, equipment and medium of a high-speed synthetic aperture nozzle

Abstract

The application belongs to the technical field of nozzle design, and relates to a design method, device, equipment and medium of a high-speed synthetic aperture nozzle. The method comprises the following steps: obtaining a transonic three-order asymptotic solution of a nozzle by using an arbitrary nozzle profile design method, and obtaining a viscous-free profile of a reference nozzle by using a characteristic line method for flow field counter-design; solving ordinary differential equations by using a reference temperature method and a fourth-order Runge-Kutta method to obtain thickness distribution of a boundary layer along the profile of the reference nozzle profile; obtaining the reference nozzle according to the viscous-free profile of the reference nozzle and the thickness distribution of the boundary layer along the profile of the reference nozzle profile; designing an outlet section of a sub-nozzle, and obtaining the sub-nozzle by lofting a stream line tracking result based on the reference nozzle by using a stream line tracking method; and combining a plurality of sub-nozzles to obtain the high-speed synthetic aperture nozzle. The application can greatly shorten the length of the nozzle while ensuring the quality of the nozzle flow field.

Description

Technical Field

[0001] This application relates to the field of nozzle design technology, and in particular to a design method, apparatus, equipment and medium for a high-speed synthetic aperture nozzle. Background Technology

[0002] The development needs of high-speed aircraft have spurred the development of ground-based wind tunnel testing equipment. As aircraft speeds increase, the Mach number of wind tunnels needs to continuously increase to meet the testing requirements. As the core equipment of a wind tunnel, the nozzle is used to accelerate the flow, enabling the flow velocity to transition from low to high speeds, providing the high-speed flow field required for aircraft testing.

[0003] In existing technologies, wind tunnel nozzles employ a single-nozzle design, meaning a single nozzle structure is used to achieve a high-speed nozzle flow field. This single-nozzle design has undergone nearly a century of development, resulting in a well-established design methodology, good design accuracy, high technological maturity, and widespread engineering applications. Currently, wind tunnels both domestically and internationally utilize this design.

[0004] However, for high-speed nozzle flow fields, based on flow characteristics, the directional velocity is approximately the normal velocity multiplied by the Mach number. The nozzle length increases with increasing Mach number, meaning that the length of a high-speed nozzle is difficult to reduce. According to the relationship between the shortest nozzle length and Mach number, a nozzle with a diameter of 1 meter will have a minimum length of 10 meters at Mach 10. In reality, under the same conditions, the nozzle length is generally 1.5 to 2.0 times longer than the shortest length. A nozzle several meters long is difficult to construct, install, and incurs extremely high material and processing costs.

[0005] In summary, the existing single-nozzle design results in extremely long high-Mach number nozzles, which are difficult to construct, install, and costly, making them unsuitable for the current development needs of high-speed aircraft testing. Summary of the Invention

[0006] Therefore, it is necessary to provide a design method, apparatus, equipment, and medium for high-speed synthetic aperture nozzles to address the aforementioned technical problems, which can significantly shorten the nozzle length while ensuring the quality of the nozzle flow field.

[0007] A design method for a high-speed synthetic aperture nozzle includes:

[0008] By employing an arbitrary nozzle profile design method, the third-order asymptotic solution of the transonic velocity of the nozzle is obtained; based on the third-order asymptotic solution of the transonic velocity, the velocity along the sound velocity line of the nozzle is obtained; based on the velocity along the sound velocity line of the nozzle, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle.

[0009] The reference temperature method and the fourth-order Runge-Kutta method are used to solve the system of ordinary differential equations, which includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor. Solving the system of ordinary differential equations yields the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle.

[0010] The reference nozzle is obtained based on the non-adhesive profile of the reference nozzle and the thickness distribution of the boundary layer along the nozzle profile.

[0011] Design the sub-nozzle exit section, and based on the reference nozzle, use the streamline tracing method to loft the streamline tracing results to obtain the sub-nozzle;

[0012] Multiple sub-nozzles are combined to obtain a high-speed synthetic aperture nozzle.

[0013] In one embodiment, the velocity along the sound velocity line of the nozzle is obtained based on the third-order transonic asymptotic solution, including:

[0014]

[0015]

[0016] In the formula, The dimensionless velocity of the flow direction is a variable with respect to the x and y coordinates; The first-order perturbation coefficient component represents the dimensionless perturbation velocity of the flow direction. For the second-order perturbation coefficient component of the dimensionless perturbation velocity flowing towards the direction, The third-order perturbation coefficient component is the velocity of the dimensionless perturbation flowing towards the direction. The spanwise dimensionless velocity is a variable with respect to the x and y coordinates; For the first-order perturbation coefficient component of the spanwise dimensionless perturbation velocity. For the second-order perturbation coefficient component of the spanwise dimensionless perturbation velocity, The third-order perturbation coefficient component of the spanwise dimensionless perturbation velocity; It is the critical speed of sound; The relative radius of curvature of the throat; is the specific heat ratio of the gas.

[0017] In one embodiment, based on the velocity along the nozzle's sound velocity line, a flow field inverse design is performed using the characteristic line method to obtain the inviscid profile of the reference nozzle, including:

[0018] ;

[0019] ;

[0020] In the formula, The y-axis coordinate is x-axis coordinate For the flow direction angle, For the flow angle increment, Mach number, For Mach number increment, For flow type, is the specific heat ratio of the gas.

[0021] In one embodiment, solving a system of ordinary differential equations to obtain the boundary layer thickness distribution along the nozzle profile of the reference nozzle includes:

[0022] ;

[0023] ;

[0024] ;

[0025] In the formula, For momentum loss thickness, The y-axis coordinate is x-axis coordinate Mach number, For compressible boundary layer shape factor, Specific heat ratio of gases The coefficient of compressible friction is For the wall angle, The coefficient of friction for incompressible flow is 1. For incompressible flow Reynolds number, is the shape factor of the incompressible flow boundary layer.

[0026] In one embodiment, the governing equations for the streamline tracing method are:

[0027] ;

[0028] In the formula, The y-axis coordinate is x-axis coordinate For spanwise velocity, The velocity is the direction of flow.

[0029] In one embodiment, the sub-nozzle exit cross-section is designed, including:

[0030] The sub-nozzle exit cross-section is designed to be square, equilateral triangle, or regular hexagonal.

[0031] In one embodiment, multiple sub-nozzles are combined to obtain a high-speed synthetic aperture nozzle, including:

[0032] Multiple sub-nozzles are combined to form an array, resulting in a high-speed synthetic aperture nozzle.

[0033] A design device for a high-speed synthetic aperture nozzle includes:

[0034] The first module is used to obtain the third-order asymptotic solution of the transonic nozzle using an arbitrary nozzle profile design method; based on the third-order asymptotic solution of the transonic nozzle, the velocity on the sound velocity line of the nozzle is obtained; based on the velocity on the sound velocity line of the nozzle, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle.

[0035] The second module is used to solve a set of ordinary differential equations using the reference temperature method and the fourth-order Runge-Kutta method. The set of ordinary differential equations includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor. Solving the set of ordinary differential equations yields the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle.

[0036] The third module is used to obtain the reference nozzle based on the non-adhesive profile of the reference nozzle and the thickness distribution of the boundary layer along the nozzle profile.

[0037] The fourth module is used to design the exit section of the sub-nozzle, and based on the reference nozzle, it uses the streamline tracing method to loft the streamline tracing results to obtain the sub-nozzle;

[0038] The fifth module is used to combine multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle.

[0039] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the above-described method.

[0040] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0041] This application has the following beneficial effects: The design method, apparatus, equipment, and medium for the aforementioned high-speed synthetic aperture nozzle adopt the concept of synthetic aperture (it should be noted that synthetic aperture is not the actual physical aperture, but rather a combination of small apertures arranged periodically to form a large aperture). It designs an array nozzle, breaking down a large-size nozzle into a small-size synthetic aperture array nozzle. This significantly shortens the length of the high-speed nozzle while ensuring the quality of the nozzle flow field. A large-size high-speed nozzle is obtained using a small-size reference nozzle; in other words, a large-size high-speed flow field can be provided with only a very short nozzle. Furthermore, it significantly reduces construction difficulty and cost, simplifies installation, and has enormous practical value and broad application prospects in high-speed wind tunnel testing and aircraft applications. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating a design method for a high-speed synthetic aperture nozzle in one embodiment;

[0043] Figure 2 This is a schematic diagram of a reference nozzle in one embodiment;

[0044] Figure 3 This is a schematic diagram of an embodiment where the sub-nozzle exit cross-section is square;

[0045] Figure 4 This is a schematic diagram of an embodiment where the sub-nozzle exit cross-section is an equilateral triangle;

[0046] Figure 5 This is a schematic diagram of an embodiment where the sub-nozzle exit cross-section is a regular hexagon;

[0047] Figure 6 This is an isometric view of a sub-nozzle in one embodiment;

[0048] Figure 7 This is a front view of the outlet of a sub-nozzle in one embodiment;

[0049] Figure 8 This is an isometric view of a high-speed synthetic aperture nozzle in one embodiment;

[0050] Figure 9 This is a front view of the exit of a high-speed synthetic aperture nozzle in one embodiment;

[0051] Figure 10 The image shows a simulation of the outlet flow field of a high-speed synthetic aperture nozzle in one embodiment.

[0052] Figure 11 This is a structural block diagram of a design device for a high-speed synthetic aperture nozzle in one embodiment;

[0053] Figure 12 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0055] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0056] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0057] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0058] This application provides a design method for a high-speed synthetic aperture nozzle, such as... Figure 1 The flowchart shown, in one embodiment, includes:

[0059] Step 101: Using an arbitrary nozzle profile design method, obtain the third-order asymptotic solution of the transonic velocity of the nozzle; based on the third-order asymptotic solution of the transonic velocity, obtain the velocity on the sound velocity line of the nozzle; based on the velocity on the sound velocity line of the nozzle, use the characteristic line method to perform flow field inverse design to obtain the inviscid profile of the reference nozzle.

[0060] Specifically:

[0061] By employing an arbitrary nozzle profile design method, the transonic third-order asymptotic solution for the nozzle is obtained;

[0062] Based on the third-order asymptotic solution of transonic velocity, the velocity along the sound velocity line of the nozzle is obtained:

[0063]

[0064]

[0065] In the formula, The dimensionless velocity of the flow direction is a variable with respect to the x and y coordinates; The first-order perturbation coefficient component represents the dimensionless perturbation velocity of the flow direction. For the second-order perturbation coefficient component of the dimensionless perturbation velocity flowing towards the direction, The third-order perturbation coefficient component is the velocity of the dimensionless perturbation flowing towards the direction. The spanwise dimensionless velocity is a variable with respect to the x and y coordinates; For the first-order perturbation coefficient component of the spanwise dimensionless perturbation velocity. For the second-order perturbation coefficient component of the spanwise dimensionless perturbation velocity, The third-order perturbation coefficient component of the spanwise dimensionless perturbation velocity; It is the critical speed of sound; The relative radius of curvature of the throat; Specific heat ratio of gases;

[0066] Based on the velocity along the sound velocity line of the nozzle, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle:

[0067] ;

[0068] ;

[0069] In the formula, The y-axis coordinate is x-axis coordinate For the flow direction angle, For the flow angle increment, Mach number, For Mach number increment, For flow type, is the specific heat ratio of the gas.

[0070] In this step, an arbitrary nozzle profile design method is used to obtain the third-order asymptotic solution of the transonic velocity of the nozzle, which is existing technology and will not be described in detail here.

[0071] Step 102: Using the reference temperature method and the fourth-order Runge-Kutta method, solve the set of ordinary differential equations, which includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor. Solve the set of ordinary differential equations to obtain the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle.

[0072] Specifically:

[0073] The reference temperature method and the fourth-order Runge-Kutta method are used to solve the system of ordinary differential equations, which includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor.

[0074] Among them, the von Kármán momentum integral relationship is:

[0075] ;

[0076] Semi-empirical formula for the coefficient of friction:

[0077] ;

[0078] Semi-empirical relation of shape factor:

[0079] ;

[0080] In the formula, For momentum loss thickness, The y-axis coordinate is x-axis coordinate Mach number, For compressible boundary layer shape factor, Specific heat ratio of gases The coefficient of compressible friction is For the wall angle, The coefficient of friction for incompressible flow is 1. For incompressible flow Reynolds number, The shape factor of the incompressible flow boundary layer;

[0081] Solving the system of ordinary differential equations yields the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle.

[0082] In this step, the reference temperature method and the fourth-order Runge-Kutta method are existing technologies and will not be described in detail here.

[0083] Step 103: Based on the non-adhesive profile of the reference nozzle and the thickness distribution of the boundary layer along the nozzle profile, the reference nozzle is obtained.

[0084] In this step, how to obtain the reference nozzle based on the inviscid profile and boundary layer thickness distribution is existing technology and will not be elaborated here.

[0085] The designed reference nozzle is as follows: Figure 2 As shown.

[0086] Step 104: Design the sub-nozzle exit section, and based on the reference nozzle, use the streamline tracing method to loft the streamline tracing results to obtain the sub-nozzle.

[0087] Specifically:

[0088] Using the streamline tracing method, the sub-nozzle exit cross-sectional shape is designed to be rectangular or square (e.g., ...). Figure 3 As shown), equilateral triangle (as shown) Figure 4 (as shown) or a regular hexagon (such as) Figure 5 As shown in the figure, to generate a uniform nozzle flow field;

[0089] Based on the exit cross-sectional shape of the sub-nozzle and the two-dimensional profile of the reference nozzle, a streamline tracing method is used to loft the streamline tracing results to obtain the sub-nozzle; the governing equations of the streamline tracing method are:

[0090] ;

[0091] In the formula, The y-axis coordinate is x-axis coordinate For spanwise velocity, The velocity is the direction of flow.

[0092] In this step, the sub-nozzle outlet cross-section is designed to be square to obtain a more universal nozzle structure and improve processing convenience; the sub-nozzle outlet cross-section is designed to be equilateral triangle to obtain a more stable nozzle structure; and the sub-nozzle outlet cross-section is designed to be regular hexagonal to obtain a thinner flow field corner region and a more uniform flow field.

[0093] It should be noted that the streamline tracing method and the lofting of the streamline tracing results are existing technologies and will not be elaborated here.

[0094] Taking a square exit cross-section of the sub-nozzle as an example, the designed sub-nozzle is as follows: Figure 6 and Figure 7 As shown.

[0095] Step 105: Combine multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle.

[0096] Specifically:

[0097] Multiple sub-nozzles are combined to form an array, so that the axes of all sub-nozzles are parallel to each other and the exit cross-sections of all sub-nozzles are coplanar, thus obtaining a high-speed synthetic aperture nozzle.

[0098] In this step, there is no limit to the number of sub-nozzles forming the array; the number can be set according to the actual situation. The more sub-nozzles there are, the larger the exit area and the greater the weight reduction.

[0099] It should be noted that how to combine multiple nozzles is existing technology and will not be elaborated here. For example, the design of the fixing frame includes multiple arrays of open grids, and a sub-nozzle is set in each open grid to combine multiple sub-nozzles.

[0100] The designed high-speed synthetic aperture nozzle, such as Figure 8 and Figure 9 As shown.

[0101] In this embodiment, the exit cross-sectional shape of a single sub-nozzle is assumed to be square, with a side length of [missing information]. The export area is , length is The spacing between the sub-nozzles is Then it forms The exit area of ​​the high-speed synthetic aperture nozzle after arraying is The length is the same as the length of a single sub-nozzle. If a single sub-nozzle is enlarged proportionally, so that its exit area reaches... Then its length will be , is the length of the high-speed synthetic orifice nozzle In other words, compared to a single nozzle of the same outlet size in the prior art, this application is [number] times larger; that is, compared to [number] nozzles of the same outlet size in the prior art. The individual nozzles form a high-speed synthetic aperture nozzle, and its length is expected to be shortened. The weight can be reduced by times. The construction cost can be reduced by a factor of two. times.

[0102] The aforementioned design method for high-speed synthetic aperture nozzles employs the concept of synthetic aperture (it should be noted that synthetic aperture is not the actual physical aperture, but rather a combination of small apertures arranged periodically to form a large aperture). It designs an array nozzle, breaking down a large-size nozzle into a small-size synthetic aperture array nozzle. This significantly shortens the length of the high-speed nozzle while ensuring the quality of the nozzle flow field. A large-size high-speed nozzle is obtained using a small-size reference nozzle; in other words, a large-size high-speed flow field can be provided with only a very short nozzle. Furthermore, it significantly reduces construction difficulty and cost, simplifies installation, and has immense practical value and broad application prospects in high-speed wind tunnel testing and aircraft applications.

[0103] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but may be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0104] In one specific embodiment, 25 sub-nozzles with a square exit cross-section are used to form a 5-way sub-nozzle system. Taking a 5-dimensional array as an example, a high-speed synthetic aperture nozzle is designed.

[0105] The exit area of ​​a single sub-nozzle is The length is 262.5 mm, the spacing between the sub-nozzles is 1 mm, and the exit area of ​​the high-speed synthetic aperture nozzle formed by the array is... The length is the same as that of a single sub-nozzle, which is 262.5 mm; if a single sub-nozzle is enlarged proportionally, so that its exit area reaches... If the length is 1342.5 mm, it will be approximately 5.1 times the length of a high-speed synthetic aperture nozzle. In other words, compared with a single nozzle of the same outlet size in the prior art, the high-speed synthetic aperture nozzle composed of 25 sub-nozzles in this application can be shortened by about 5.1 times, reduced in weight by about 5.1 times, and reduced in construction cost by about 5.1 times.

[0106] Computational fluid dynamics methods are used to calculate the flow field of a large-sized synthetic aperture nozzle, such as... Figure 10 As shown, the flow field of the synthetic aperture nozzle is uniform, which meets the requirements of aircraft testing and verifies the feasibility of the method in this application.

[0107] This application also provides an apparatus, such as Figure 11 As shown, in one embodiment, it includes: a first module 1101, a second module 1102, a third module 1103, a fourth module 1104, and a fifth module 1105, wherein:

[0108] The first module is used to obtain the third-order asymptotic solution of the transonic nozzle using an arbitrary nozzle profile design method; based on the third-order asymptotic solution of the transonic nozzle, the velocity on the sound velocity line of the nozzle is obtained; based on the velocity on the sound velocity line of the nozzle, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle.

[0109] The second module is used to solve a set of ordinary differential equations using the reference temperature method and the fourth-order Runge-Kutta method. The set of ordinary differential equations includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor. Solving the set of ordinary differential equations yields the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle.

[0110] The third module is used to obtain the reference nozzle based on the non-adhesive profile of the reference nozzle and the thickness distribution of the boundary layer along the nozzle profile.

[0111] The fourth module is used to design the exit section of the sub-nozzle, and based on the reference nozzle, it uses the streamline tracing method to loft the streamline tracing results to obtain the sub-nozzle;

[0112] The fifth module is used to combine multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle.

[0113] Specific limitations regarding the design apparatus for a high-speed synthetic aperture nozzle can be found in the above description of the design method for a high-speed synthetic aperture nozzle, and will not be repeated here. Each module in the above apparatus can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0114] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 12 As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a design method for a high-speed synthetic aperture nozzle. The display screen can be an LCD screen or an e-ink display screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0115] Those skilled in the art will understand that Figure 12 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0116] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the method described above.

[0117] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0118] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0119] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended application documents.

Claims

1. A design method for a high-speed synthetic aperture nozzle, characterized in that, include: By employing an arbitrary nozzle profile design method, the transonic third-order asymptotic solution for the nozzle is obtained; The velocity along the sound velocity line of the nozzle is obtained based on the third-order asymptotic solution of transonic velocity. Based on the velocity along the sound velocity line of the nozzle, the flow field is reverse-designed using the characteristic line method to obtain the inviscid profile of the reference nozzle; Based on the velocity along the nozzle's sound velocity line, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle, including: In the formula, The y-axis coordinate is x-axis coordinate For the flow direction angle, For the flow angle increment, Mach number, For Mach number increment, For flow type, Specific heat ratio of gases; The reference temperature method and the fourth-order Runge-Kutta method are used to solve the system of ordinary differential equations, which includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor. Solving the system of ordinary differential equations yields the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle. The reference nozzle is obtained based on the non-adhesive profile of the reference nozzle and the thickness distribution of the boundary layer along the nozzle profile. Design the sub-nozzle exit cross-section, and based on the reference nozzle, use the streamline tracing method to loft the streamline tracing results to obtain the sub-nozzle; design the sub-nozzle exit cross-section, including: designing the sub-nozzle exit cross-section as a square, equilateral triangle or regular hexagon; Combining multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle; combining multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle includes: combining multiple sub-nozzles to form an array to obtain a high-speed synthetic aperture nozzle.

2. The design method for a high-speed synthetic aperture nozzle according to claim 1, characterized in that, Based on the third-order asymptotic solution of transonic velocity, the velocities along the sound velocity line of the nozzle are obtained, including: In the formula, The dimensionless velocity of the flow direction is a variable with respect to the x and y coordinates; The first-order perturbation coefficient component represents the dimensionless perturbation velocity of the flow direction. For the second-order perturbation coefficient component of the dimensionless perturbation velocity of the flow direction, The third-order perturbation coefficient component is the velocity of the dimensionless perturbation flowing towards the direction. The spanwise dimensionless velocity is a variable with respect to the x and y coordinates; For the first-order perturbation coefficient component of the spanwise dimensionless perturbation velocity. For the second-order perturbation coefficient component of the spanwise dimensionless perturbation velocity, The third-order perturbation coefficient component of the spanwise dimensionless perturbation velocity; It is the critical speed of sound; The relative radius of curvature of the throat; is the specific heat ratio of the gas.

3. The design method for a high-speed synthetic aperture nozzle according to claim 2, characterized in that, Solving the system of ordinary differential equations yields the boundary layer thickness distribution along the nozzle profile of the reference nozzle, including: In the formula, For momentum loss thickness, The y-axis coordinate is x-axis coordinate Mach number, For compressible boundary layer shape factor, Specific heat ratio of gases The coefficient of compressible friction, For the wall angle, The coefficient of friction for incompressible flow is... For incompressible flow Reynolds number, is the shape factor of the incompressible flow boundary layer.

4. The design method for a high-speed synthetic aperture nozzle according to claim 3, characterized in that, The governing equations for the streamline tracing method are: In the formula, The y-axis coordinate is x-axis coordinate For spanwise velocity, The velocity is the direction of flow.

5. A design device for a high-speed synthetic aperture nozzle, characterized in that, The design method of a high-speed synthetic aperture nozzle according to any one of claims 1 to 4 includes: The first module is used to obtain the third-order asymptotic solution of the transonic nozzle using an arbitrary nozzle profile design method; based on the third-order asymptotic solution, the velocity along the sound velocity line of the nozzle is obtained; based on the velocity along the sound velocity line of the nozzle, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle; based on the velocity along the sound velocity line of the nozzle, the flow field is inversely designed using the characteristic line method to obtain the inviscid profile of the reference nozzle, including: In the formula, The y-axis coordinate is x-axis coordinate For the flow direction angle, For the flow angle increment, Mach number, For Mach number increment, For flow type, Specific heat ratio of gases; The second module is used to solve a set of ordinary differential equations using the reference temperature method and the fourth-order Runge-Kutta method. The set of ordinary differential equations includes the von Kármán momentum integral relation, the semi-empirical relation of the friction coefficient, and the semi-empirical relation of the shape factor. Solving the set of ordinary differential equations yields the thickness distribution of the boundary layer along the nozzle profile of the reference nozzle. The third module is used to obtain the reference nozzle based on the non-adhesive profile of the reference nozzle and the thickness distribution of the boundary layer along the nozzle profile. The fourth module is used to design the sub-nozzle exit cross-section, and based on the reference nozzle, uses the streamline tracing method to loft the streamline tracing results to obtain the sub-nozzle; the sub-nozzle exit cross-section is designed, including: designing the sub-nozzle exit cross-section as a square, equilateral triangle or regular hexagon; The fifth module is used to combine multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle; combining multiple sub-nozzles to obtain a high-speed synthetic aperture nozzle includes: combining multiple sub-nozzles to form an array to obtain a high-speed synthetic aperture nozzle.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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