A design method, device, equipment and medium of a supersonic convergent-divergent nozzle

Abstract

The application belongs to the technical field of nozzle design, and relates to a design method, device, equipment and medium of a supersonic point convergence nozzle. The method comprises the following steps: obtaining design parameters of the supersonic point convergence nozzle, obtaining a point convergence flow control equation, a characteristic line equation of supersonic flow and a compatibility equation, and obtaining a left-running characteristic line at a nozzle outlet and a right-running characteristic line at a nozzle throat by using an improved Euler method; taking the left-running characteristic line at the nozzle outlet, the right-running characteristic line at the nozzle throat and a symmetry axis of the nozzle as boundary conditions, and obtaining a point convergence nozzle flow field by using a characteristic line method; obtaining a supersonic surface of the supersonic point convergence nozzle by using a mass conservation formula along the right-running characteristic line at the nozzle throat in the obtained point convergence nozzle flow field; designing a converging section of the supersonic point convergence nozzle, connecting the converging section with the supersonic surface of the supersonic point convergence nozzle, and then correcting to obtain a supersonic viscous point convergence nozzle. The application can provide supersonic point convergence flow.

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 supersonic point-collecting nozzle. Background Technology

[0002] The forward-looking window of a warhead is crucial for high-speed aircraft. For example, it can be used for optical detection, target search, tracking, and identification; it can also be used for infrared detection, capturing the infrared radiation of a target and using the infrared temperature difference between the target and its surroundings to detect and track the target; and it can also be used for radar detection, transmitting and receiving radar waves, enabling the aircraft to range, measure speed, and locate targets in complex weather and electromagnetic environments.

[0003] As the speed of a high-speed aircraft increases, the warhead experiences greater air friction, resulting in higher temperatures. At different altitudes, the temperature generally ranges from 200K to 300K. However, as the Mach number of the aircraft increases, the flow at the warhead's leading edge stagnates, causing the total temperature to increase rapidly. For example, at Mach 6, the temperature at the warhead's leading edge can reach 1500K. The forward-looking window cannot directly withstand the high temperatures generated by the high-speed flow, which could lead to thermal damage to structures such as the optical window glass. Therefore, cooling is necessary. Supersonic film cooling is the optimal solution for cooling the forward-looking window of high-speed aircraft warheads because of its low temperature, high speed, high momentum, and excellent blocking effect on the hot airflow. Furthermore, the cooling process does not affect the optical, infrared, and radar performance of the forward-looking window.

[0004] Supersonic air film requires the use of supersonic nozzles. After nearly a century of development, the fundamental theories and methods of supersonic nozzle design have been continuously updated and improved. Existing design methods offer good accuracy, high technological maturity, and wide engineering applications.

[0005] In existing technologies, the conventional design method for supersonic nozzles is as follows: An arbitrary nozzle profile design method (such as a third-order transonic asymptotic solution) is used to design a reference nozzle. Then, using the characteristic line method, the inviscid profile of the reference nozzle is obtained through flow field inverse design. The reference temperature method and the fourth-order Runge-Kutta method are used to solve a system of ordinary differential equations, thereby obtaining the boundary layer thickness distribution along the nozzle profile. The designed supersonic film nozzle profile is as follows: Figure 1 As shown, existing supersonic nozzle design methods are applicable to planar flow or axisymmetric flow, with the flow direction pointing downstream of the x-axis (e.g., Figure 1 (middle arrow direction).

[0006] However, as Figure 2 As shown, for the forward viewing window of the warhead, the direction of the film gas flow is towards the center point of the warhead (e.g., Figure 2(In the direction of the middle arrow), this is physically a supersonic point sink flow, and currently no literature discloses a supersonic nozzle design method that can achieve supersonic point sink flow; furthermore, from Figure 2 It can also be seen that the x-axis is the warhead's rotation axis and the r-axis is the radial direction. The coordinate system and the flow direction are different from the existing supersonic nozzle design methods, which leads to the supersonic point-collecting nozzle design method being different from the existing supersonic nozzle design methods.

[0007] In summary, existing supersonic nozzle design methods cannot achieve supersonic point flow and are not suitable for cooling the forward-looking window of a warhead. Summary of the Invention

[0008] Therefore, it is necessary to provide a design method, apparatus, equipment, and medium for a supersonic point-collector nozzle to address the aforementioned technical problems. This method and medium can design a supersonic point-collector nozzle to provide supersonic point flow for cooling the forward-looking optical window of a warhead, thus meeting the cooling requirements of the warhead's forward-looking window.

[0009] A design method for a supersonic point-jet nozzle includes:

[0010] By obtaining the design parameters of the supersonic point sink nozzle, the control equation for the point sink flow is obtained through mass conservation; by obtaining the design parameters of the supersonic point sink nozzle, the characteristic line equation and compatibility equation for the supersonic flow are obtained.

[0011] Based on the flow control equations, characteristic line equations, and compatibility equations of the point sink, the improved Euler method is used to obtain the leftward characteristic line of the nozzle exit; based on the flow control equations, characteristic line equations, and compatibility equations of the point sink, the improved Euler method is used to obtain the rightward characteristic line of the nozzle throat.

[0012] Using the leftward characteristic line at the nozzle exit, the rightward characteristic line at the nozzle throat, and the nozzle's axis of symmetry as boundary conditions, the flow field of the point sink nozzle is obtained using the characteristic line method.

[0013] Within the obtained flow field of the point sink nozzle, the supersonic profile of the supersonic point sink nozzle is obtained by using the mass conservation equation along the rightward characteristic line of the nozzle throat.

[0014] Design the contraction section of the supersonic point nozzle and connect it with the supersonic profile of the supersonic point nozzle to obtain a non-sticky point nozzle; perform viscosity correction on the non-sticky point nozzle to obtain a supersonic sticky point nozzle.

[0015] In one embodiment, the design parameters of the supersonic point sink nozzle are obtained, and the point sink flow control equations are derived from mass conservation, including:

[0016] The design parameters of the supersonic point nozzle are obtained, and the mass conservation equation is derived from the law of mass conservation.

[0017] By obtaining the isentropic flow parameters of the point sink, and substituting them into the mass conservation equation, the governing equations of the point sink flow are obtained.

[0018] In one embodiment, the point sink flow field parameters are obtained from the isentropic flow of the point sink, and then substituted into the mass conservation equation to obtain the governing equations of the point sink flow, including:

[0019] The flow field parameters of the point sink are obtained by isentropically analyzing the flow at the point sink:

[0020] ;

[0021] ;

[0022] ;

[0023] ;

[0024] ;

[0025] In the formula, For static temperature, For total temperature, For static pressure, For total pressure, Specific heat ratio of gases Mach number, The gas constant is... Speed ​​of sound;

[0026] Substituting the flow field parameters of the point sink into the mass conservation equation, we obtain the relationship between the Mach number and the radius:

[0027] ;

[0028] Based on the relationship between Mach number and radius, the flow control equations for the point sink are obtained:

[0029] ;

[0030] In the formula, Radial coordinates, The radial coordinates are in a critical state. For airflow density, The airflow density at the critical state. airflow x Towards speed, airflow in a critical state x Towards speed, Position 1 Position two, For position one, the Mach number is... Let be the Mach number at position two.

[0031] In one embodiment, the design parameters of the supersonic point nozzle are obtained to derive the characteristic line equation and compatibility equation for supersonic flow, including:

[0032] ;

[0033] ;

[0034] In the formula, airflow The velocity component in the direction, airflow The velocity component in the direction, For the speed of sound, The slope of the characteristic line. For the flow direction angle, It is the Mach angle.

[0035] In one embodiment, based on the point sink flow control equation, characteristic line equation, and compatibility equation, a modified Euler method is used to obtain the leftward-moving characteristic line of the nozzle exit; based on the point sink flow control equation, characteristic line equation, and compatibility equation, a modified Euler method is used to obtain the rightward-moving characteristic line of the nozzle throat, including:

[0036] Based on the flow control equation, characteristic line equation, and compatibility equation of the sink, and combined with the nozzle exit Mach number, the improved Euler method is used to obtain the leftward characteristic line of the nozzle exit.

[0037] Based on the flow control equations, characteristic line equations, and compatibility equations of the nozzle sink, and combined with the Mach number at the nozzle throat, the rightward characteristic line of the nozzle throat is obtained using the improved Euler method.

[0038] In one embodiment, the converging section of the supersonic point nozzle is designed, including:

[0039] ;

[0040] In the formula, x-axis coordinate The height of the contraction section entrance. The height of the larynx. Radial coordinates, This is the length of the contraction segment.

[0041] In one embodiment, viscous modification of a non-viscous nozzle includes:

[0042] ;

[0043] In the formula, To provide the coordinates of the adhesive surface of the corrected nozzle. The coordinates of the non-adhesive surface of the nozzle; For displacement thickness, The angle of the wall surface for the non-adhesive surface.

[0044] A design device for a supersonic point-jet nozzle includes:

[0045] The first module is used to obtain the design parameters of the supersonic point sink nozzle, and obtain the control equation of the point sink flow from the mass conservation; and obtain the characteristic line equation and compatibility equation of the supersonic flow from the design parameters of the supersonic point sink nozzle.

[0046] The second module is used to obtain the leftward characteristic line of the nozzle exit using the improved Euler method based on the point sink flow control equation, characteristic line equation, and compatibility equation; and to obtain the rightward characteristic line of the nozzle throat using the improved Euler method based on the point sink flow control equation, characteristic line equation, and compatibility equation.

[0047] The third module is used to obtain the flow field of the point sink nozzle by using the leftward characteristic line of the nozzle exit, the rightward characteristic line of the nozzle throat, and the axis of symmetry of the nozzle as boundary conditions and the characteristic line method.

[0048] The fourth module is used to obtain the supersonic profile of the supersonic point-collector nozzle by using the mass conservation formula along the rightward characteristic line of the nozzle throat within the obtained point-collector nozzle flow field.

[0049] The fifth module is used to design the contraction section of the supersonic point nozzle and connect it with the supersonic profile of the supersonic point nozzle to obtain a non-sticky point nozzle; the non-sticky point nozzle is then modified for viscosity to obtain a supersonic sticky point nozzle.

[0050] 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.

[0051] 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.

[0052] The aforementioned design method, apparatus, equipment, and medium for supersonic point sink nozzles are based on the physical nature of supersonic point sink flow. A point sink flow control equation is established, and combined with the characteristic line equation and compatibility equation, the characteristic line method for supersonic flow is used to design a supersonic point sink nozzle. This nozzle can provide uniform supersonic point sink flow and a ring-shaped gas film with the correct flow direction to cool the forward-looking optical window of the aircraft warhead, meeting the cooling requirements of the warhead's forward-looking window. Furthermore, the nozzle exit flow field is uniform. Attached Figure Description

[0053] Figure 1A schematic diagram of the supersonic film nozzle profile designed using existing technology;

[0054] Figure 2 A schematic diagram of the supersonic point jet nozzle for the forward-looking window of the warhead, which is currently required.

[0055] Figure 3 This is a flowchart illustrating a design method for a supersonic point jet nozzle in one embodiment.

[0056] Figure 4 This is a schematic diagram of the leftward characteristic line of the outlet of a supersonic point jet nozzle in one embodiment.

[0057] Figure 5 This is a schematic diagram of the rightward characteristic line of the throat of a supersonic point jet nozzle in one embodiment.

[0058] Figure 6 This is a schematic diagram illustrating viscosity correction for a non-sticky nozzle in one embodiment;

[0059] Figure 7 This is a schematic diagram of the profile of a supersonic viscous nozzle in one embodiment;

[0060] Figure 8 Mach number contour plot of the supersonic point nozzle flow field in a specific embodiment;

[0061] Figure 9 This is a diagram showing the Mach number distribution at the nozzle exit of a supersonic point-mass nozzle in a specific embodiment.

[0062] Figure 10 This is a structural block diagram of a design device for a supersonic point jet nozzle in one embodiment;

[0063] Figure 11 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] This application provides a design method for a supersonic point jet nozzle, such as Figure 3 The flowchart shown, in one embodiment, includes:

[0069] Step 301: Obtain the design parameters of the supersonic point sink nozzle, and obtain the control equation of the point sink flow by mass conservation; obtain the characteristic line equation and compatibility equation of the supersonic flow by obtaining the design parameters of the supersonic point sink nozzle.

[0070] Specifically:

[0071] Conventional supersonic nozzles, except for the boundary layer at the wall, exhibit potential flow, which can be scaled. Unlike conventional supersonic nozzles, supersonic point sink nozzles, due to the presence of a rotational axis, experience changes in mass flow rate, Mach number, and wave-damping performance due to scaling. Therefore, the design parameters of the supersonic point sink nozzle must be obtained in advance based on the requirements of the engineering application, specifically including:

[0072] ① Design Mach number ;

[0073] ② Point-of-use nozzle exit height ;

[0074] ③ Width of nozzle outlet spray slot ;

[0075] ④ Nozzle length ;

[0076] ⑤ Thermodynamic parameters: specific heat ratio of gas Total temperature Total pressure ;

[0077] Based on the design parameters of the supersonic point sink nozzle, the mass conservation equation is obtained by mass conservation; the point sink flow field parameters are obtained by isentropic point sink flow; and the point sink flow control equation is obtained based on the mass conservation equation and the point sink flow field parameters.

[0078] Based on the design parameters of the supersonic point nozzle, the characteristic line equation and compatibility equation of the supersonic flow are obtained by using the gas dynamics equation of supersonic steady inviscid flow in an axisymmetric coordinate system and the method of characteristics.

[0079] More specifically:

[0080] Based on the design parameters of the supersonic point sink nozzle, for point sink flow, the mass conservation law is as follows:

[0081] ;

[0082] The geometric relationship is:

[0083] ;

[0084] Substituting the geometric relationships into the law of conservation of mass, we obtain the equation for the conservation of mass:

[0085] ;

[0086] In the formula, For airflow density, The airflow density at the critical state. airflow x Towards speed, airflow in a critical state x Towards speed, For the flow cross-sectional area, The cross-sectional area of ​​the flow at the critical state. Radial coordinates, These are the radial coordinates at the critical state; it should be noted that being at the critical state means... The state;

[0087] The flow field parameters of the point sink are obtained by isentropically analyzing the flow at the point sink:

[0088] ;

[0089] ;

[0090] ;

[0091] ;

[0092] ;

[0093] In the formula, For static temperature, For total temperature, For static pressure, For total pressure, Specific heat ratio of gases Mach number, The gas constant is... Speed ​​of sound;

[0094] Substituting the flow field parameters of the point sink into the mass conservation equation, we obtain the relationship between the Mach number and the radius:

[0095] ;

[0096] Based on the relationship between Mach number and radius, the flow control equations for the point sink are obtained:

[0097] ;

[0098] In the formula, Position 1 Position two, For position one, the Mach number is... The Mach number for position two;

[0099] Based on the design parameters of the supersonic point nozzle, the gas dynamics equation for supersonic steady inviscid flow in an axisymmetric coordinate system is:

[0100] ;

[0101] Using the method of characteristics, the equations of the characteristic lines are obtained as follows:

[0102] ;

[0103] The compatibility equation is:

[0104] ;

[0105] In the formula, airflow The velocity component in the direction, airflow The velocity component in the direction, For the speed of sound, The slope of the characteristic line. For the flow direction angle, It is the Mach angle.

[0106] In this step, the method of characteristics is existing technology and will not be described in detail here.

[0107] Step 302: Based on the point sink flow control equation, characteristic line equation, and compatibility equation, the improved Euler method is used to obtain the leftward characteristic line of the nozzle exit; based on the point sink flow control equation, characteristic line equation, and compatibility equation, the improved Euler method is used to obtain the rightward characteristic line of the nozzle throat.

[0108] Specifically:

[0109] Based on the flow control equations, characteristic line equations, and compatibility equations of the point sink, and combined with the nozzle exit Mach number (i.e., the design Mach number), the improved Euler method (which is the existing technology) is used to obtain the leftward characteristic line of the nozzle exit.

[0110] Based on the flow control equations, characteristic line equations, and compatibility equations of the point sink, and combined with the Mach number at the nozzle throat, the improved Euler method (which is the existing technology) is used to obtain the rightward characteristic line of the nozzle throat.

[0111] The improved Euler method used in this step is existing technology and will not be elaborated upon here.

[0112] The leftward characteristic line of the nozzle exit obtained by the design is as follows: Figure 4 As shown, the rightward characteristic line of the nozzle throat obtained by the design is as follows: Figure 5 As shown. It should be noted that, due to the influence of the point sink flow, the closer the flow is to the x-axis of rotation, the lower the velocity, the smaller the Mach number, the larger the Mach angle, and the larger the slope of the characteristic line. This means that the leftward characteristic line at the nozzle exit and the rightward characteristic line at the nozzle throat are not straight characteristic lines, but curved.

[0113] Step 303: Using the leftward characteristic line at the nozzle exit, the rightward characteristic line at the nozzle throat, and the nozzle's axis of symmetry as boundary conditions, the characteristic line method is used to obtain the flow field of the point sink nozzle.

[0114] Specifically:

[0115] Using the leftward characteristic line at the nozzle exit, the rightward characteristic line at the nozzle throat, and the nozzle's axis of symmetry as boundary conditions, the flow field is inversely designed using the characteristic line method based on the nozzle exit height, nozzle slit width, nozzle length, characteristic line equation, and compatibility equation, thus obtaining the flow field of the nozzle.

[0116] In this step, the axis of symmetry of the nozzle is the r-axis.

[0117] It should be noted that how to calculate the flow field using the method of characteristics under boundary conditions is an existing technology and will not be elaborated here.

[0118] Step 304: Within the obtained point-collector nozzle flow field, along the rightward characteristic line of the nozzle throat, the supersonic profile of the supersonic point-collector nozzle is obtained using the mass conservation equation.

[0119] The mass conservation equation is expressed as:

[0120] ;

[0121] In the formula, This refers to the nozzle mass flow rate. Where is the nozzle wall radius. For airflow density, airflow The velocity component in the direction, The coordinates are x-axis coordinates.

[0122] In this step, how to obtain the nozzle profile by following the feature line and using the mass conservation formula is existing technology and will not be elaborated here.

[0123] Step 305: Design the contraction section of the supersonic point nozzle and connect it with the supersonic profile of the supersonic point nozzle to obtain a non-sticky point nozzle; perform viscosity correction on the non-sticky point nozzle to obtain a supersonic sticky point nozzle.

[0124] The design includes the contraction section of the supersonic point jet nozzle:

[0125] ;

[0126] In the formula, x-axis coordinate The height of the contraction section entrance. The height of the larynx. Radial coordinates, The length of the contraction segment;

[0127] Adhesion correction for non-sticky nozzles:

[0128] ;

[0129] In the formula, To provide the coordinates of the adhesive surface of the corrected nozzle. The coordinates of the non-adhesive surface of the nozzle; For displacement thickness, The angle of the wall surface for the non-adhesive surface.

[0130] In this step, viscosity correction is as follows: Figure 6 As shown (where 1 is the inviscid surface, 2 is the viscous surface, and 3 is the modified boundary layer), the designed supersonic viscous nozzle is as follows: Figure 7 As shown.

[0131] The above-mentioned design method for supersonic point sink nozzles starts from the physical essence of supersonic point sink flow, establishes the point sink flow control equation, and combines the characteristic line equation and compatibility equation. Using the characteristic line method of supersonic flow, a supersonic point sink nozzle is designed, which can provide uniform supersonic point sink flow and provide an annular gas film with the correct flow direction to cool the forward-looking optical window of the aircraft warhead. It can meet the cooling requirements of the forward-looking window of the warhead, and the flow field at the nozzle exit is uniform.

[0132] 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 in this document, there is no strict order in which these steps are executed, and they can be performed in other orders. Furthermore, 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 completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0133] In one specific embodiment, a supersonic point jet nozzle was designed and verified using computational fluid dynamics methods to obtain numerical simulation results of the supersonic point jet nozzle flow field.

[0134] like Figure 8 As shown, the supersonic point-collecting nozzle achieves speeds from low to supersonic, providing a uniform point-collecting airflow and ensuring uniform flow at the nozzle exit.

[0135] like Figure 9 As shown, the Mach number distribution at the exit of the supersonic point nozzle is almost a straight line, which helps to better match the external flow field, reduce drag, or avoid flow separation.

[0136] This application also provides a design device for a supersonic point jet nozzle, such as... Figure 10 As shown, in one embodiment, it includes: a first module 1001, a second module 1002, a third module 1003, a fourth module 1004, and a fifth module 1005, wherein:

[0137] The first module is used to obtain the design parameters of the supersonic point sink nozzle, and obtain the control equation of the point sink flow from the mass conservation; and obtain the characteristic line equation and compatibility equation of the supersonic flow from the design parameters of the supersonic point sink nozzle.

[0138] The second module is used to obtain the leftward characteristic line of the nozzle exit using the improved Euler method based on the point sink flow control equation, characteristic line equation, and compatibility equation; and to obtain the rightward characteristic line of the nozzle throat using the improved Euler method based on the point sink flow control equation, characteristic line equation, and compatibility equation.

[0139] The third module is used to obtain the flow field of the point sink nozzle by using the leftward characteristic line of the nozzle exit, the rightward characteristic line of the nozzle throat, and the axis of symmetry of the nozzle as boundary conditions and the characteristic line method.

[0140] The fourth module is used to obtain the supersonic profile of the supersonic point-collector nozzle by using the mass conservation formula along the rightward characteristic line of the nozzle throat within the obtained point-collector nozzle flow field.

[0141] The fifth module is used to design the contraction section of the supersonic point nozzle and connect it with the supersonic profile of the supersonic point nozzle to obtain a non-sticky point nozzle; the non-sticky point nozzle is then modified for viscosity to obtain a supersonic sticky point nozzle.

[0142] Specific limitations regarding the design device for a supersonic point jet nozzle can be found in the above description of the design method for a supersonic point jet nozzle, and will not be repeated here. Each module in the above device 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 in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0143] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 11 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 stored in the non-volatile storage media. The network interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a design method for a supersonic point jet 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.

[0144] Those skilled in the art will understand that Figure 11The 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0149] 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.

[0150] 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 supersonic point-jet nozzle, characterized in that, include: The design parameters of the supersonic point sink nozzle are obtained, and the flow control equation of the point sink is obtained by mass conservation. The design parameters of the supersonic point nozzle are obtained, and the characteristic line equation and compatibility equation of the supersonic flow are derived. Based on the flow control equation, characteristic line equation, and compatibility equation of the sink, the improved Euler method is used to obtain the leftward characteristic line of the nozzle exit. Based on the flow control equation, characteristic line equation, and compatibility equation of the sink, the improved Euler method is used to obtain the rightward characteristic line of the nozzle throat; Using the leftward characteristic line at the nozzle exit, the rightward characteristic line at the nozzle throat, and the nozzle's axis of symmetry as boundary conditions, the flow field of the point sink nozzle is obtained using the characteristic line method. Within the obtained flow field of the point sink nozzle, the supersonic profile of the supersonic point sink nozzle is obtained by using the mass conservation equation along the rightward characteristic line of the nozzle throat. Design the contraction section of the supersonic point nozzle and connect it with the supersonic profile of the supersonic point nozzle to obtain a non-sticky point nozzle; perform viscosity correction on the non-sticky point nozzle to obtain a supersonic sticky point nozzle.

2. The design method of a supersonic point-jet nozzle according to claim 1, characterized in that, The design parameters of the supersonic point sink nozzle are obtained, and the flow control equations for the point sink are derived from the law of mass conservation, including: The design parameters of the supersonic point nozzle are obtained, and the mass conservation equation is derived from the law of mass conservation. By obtaining the isentropic flow parameters of the point sink, and substituting them into the mass conservation equation, the governing equations of the point sink flow are obtained.

3. The design method of a supersonic point-jet nozzle according to claim 2, characterized in that, By using the isentropic principle of point sink flow, the flow field parameters of the point sink are obtained. Substituting these parameters into the mass conservation equation, the governing equations of the point sink flow are derived, including: The flow field parameters of the point sink are obtained by isentropically analyzing the flow at the point sink: ； ； ； ； ； In the formula, For static temperature, For total temperature, For static pressure, For total pressure, Specific heat ratio of gases Mach number, The gas constant is... Speed ​​of sound; Substituting the flow field parameters of the point sink into the mass conservation equation, we obtain the relationship between the Mach number and the radius: ； Based on the relationship between Mach number and radius, the control equations for point sink flow are obtained: ； In the formula, Radial coordinates, The radial coordinates are in a critical state. For airflow density, The airflow density at the critical state. airflow x Towards speed, airflow in a critical state x Towards speed, Position 1 Position two, For position one, the Mach number is... Let be the Mach number at position two.

4. A design method for a supersonic point-jet nozzle according to any one of claims 1 to 3, characterized in that, Obtain the design parameters of the supersonic point nozzle to derive the characteristic line equations and compatibility equations for supersonic flow, including: ； ； In the formula, airflow The velocity component in the direction, airflow The velocity component in the direction, For the speed of sound, The slope of the characteristic line. For the flow direction angle, It is the Mach angle.

5. A design method for a supersonic point-jet nozzle according to any one of claims 1 to 3, characterized in that, Based on the flow control equation, characteristic line equation, and compatibility equation of the sink, the improved Euler method is used to obtain the leftward characteristic line of the nozzle exit. Based on the flow control equations, characteristic line equations, and compatibility equations of the nozzle sink, the improved Euler method is used to obtain the rightward characteristic line of the nozzle throat, including: Based on the flow control equation, characteristic line equation, and compatibility equation of the point sink, and combined with the nozzle exit Mach number, the improved Euler method is used to obtain the leftward characteristic line of the nozzle exit. Based on the flow control equations, characteristic line equations, and compatibility equations of the nozzle sink, and combined with the Mach number at the nozzle throat, the rightward characteristic line of the nozzle throat is obtained using the improved Euler method.

6. A design method for a supersonic point-jet nozzle according to any one of claims 1 to 3, characterized in that, The design of the converging section of the supersonic point jet nozzle includes: ； In the formula, x-axis coordinate The height of the contraction section entrance. The height of the larynx. Radial coordinates, This is the length of the contraction segment.

7. A design method for a supersonic point-jet nozzle according to any one of claims 1 to 3, characterized in that, Adhesion correction for non-sticky nozzles includes: ； In the formula, To provide the coordinates of the adhesive surface of the corrected nozzle. The coordinates of the non-adhesive surface of the nozzle; For displacement thickness, The angle of the wall surface for the non-adhesive surface.

8. A design device for a supersonic point-jet nozzle, characterized in that, include: The first module is used to obtain the design parameters of the supersonic point sink nozzle and, based on the law of mass conservation, to obtain the point sink flow control equation. The design parameters of the supersonic point nozzle are obtained, and the characteristic line equation and compatibility equation of the supersonic flow are derived. The second module is used to obtain the leftward characteristic line of the nozzle exit by adopting the improved Euler method based on the point flow control equation, characteristic line equation and compatibility equation. Based on the flow control equation, characteristic line equation, and compatibility equation of the sink, the improved Euler method is used to obtain the rightward characteristic line of the nozzle throat; The third module is used to obtain the flow field of the point sink nozzle by using the leftward characteristic line of the nozzle exit, the rightward characteristic line of the nozzle throat, and the axis of symmetry of the nozzle as boundary conditions and the characteristic line method. The fourth module is used to obtain the supersonic profile of the supersonic point-collector nozzle by using the mass conservation formula along the rightward characteristic line of the nozzle throat within the obtained point-collector nozzle flow field. The fifth module is used to design the contraction section of the supersonic point nozzle and connect it with the supersonic profile of the supersonic point nozzle to obtain a non-sticky point nozzle; the non-sticky point nozzle is then modified for viscosity to obtain a supersonic sticky point nozzle.

9. 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 7.

10. 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 7.

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