A design method for a three-dimensional variable-section unilateral expansion nozzle with a large lateral expansion angle

Abstract

The present application belongs to the technical field of aero-engine nozzles, and particularly relates to a design method for a three-dimensional variable-section, single-sided expansion nozzle with a large lateral expansion angle. The method comprises the following steps: Step 1, obtaining nozzle aerodynamic parameters and dimensional constraint parameters; Step 2, defining the nozzle sidewall as a straight configuration and calculating the lateral expansion angle; Step 3, defining the nozzle lower wall as a straight configuration and calculating the lower wall expansion angle; Step 4, obtaining the nozzle upper wall configuration according to the shortest length nozzle theory and the single-sided expansion nozzle design method considering lateral expansion; Step 5, directly shortening the nozzle upper wall and the nozzle lower wall according to the nozzle upper wall length to obtain a reference nozzle configuration, and determining whether the nozzle upper wall height of the reference nozzle configuration meets the dimensional constraint requirements. If so, outputting the reference nozzle configuration and entering Step 6; if not, adjusting the nozzle aerodynamic parameters and returning to Step 4; Step 6, performing a three-dimensional variable-section nozzle design.

Description

Technical Field

[0001] The present application belongs to the technical field of aero-engine nozzles, and in particular relates to a design method for a three-dimensional variable-cross-section unilateral expansion nozzle with a large lateral expansion angle. Background Art

[0002] In recent years, hypersonic technology has continuously promoted the emergence of new hypersonic vehicles, such as hypersonic cruise missiles, hypersonic aircraft, and spaceplanes, with significant strategic significance both military and economically. Scramjet engines, with their high specific impulse at high Mach numbers, simple structure, and lack of oxidizer, have become the optimal propulsion system for hypersonic vehicles. The nozzle is a crucial component in generating thrust in ramjet engines. At a flight Mach number of 6, the nozzle contributes 70% of the total thrust of the ramjet engine. A 1% decrease in nozzle thrust results in a 4% decrease in installed engine thrust. Due to the high pressure drop during hypersonic flight, the nozzle exit area under ideal expansion conditions is very large, resulting in excessive engine weight and height. Therefore, scramjet nozzles often adopt a single-side expansion nozzle design. A single-side expansion nozzle uses the lower surface of the aircraft's rear body as the upper expansion surface, while the lower expansion surface is shortened, allowing the airflow to expand freely on the lower side. The unilateral expansion nozzle has many advantages, such as simple structure, easy integration with aircraft design, wide working range, and ability to generate lift.

[0003] With the development of hypersonic technology, three-dimensional flow channel propulsion systems using circular or elliptical scramjet combustion chambers are gaining increasing attention. Compared with traditional two-dimensional flow channels, circular three-dimensional flow channels have a smaller wetted area, which can reduce viscous losses. In addition, they are easier to integrate with the fuselage. At the same time, the design of nozzles is often subject to strict constraints on the geometry and size of the aircraft body. In order to achieve the integration of the engine and the fuselage, the nozzle outlet shape is no longer a simple circle or rectangle, and the nozzle is no longer a simple binary or axisymmetric configuration, but a more complex spatial surface. Therefore, as a thrust nozzle, this type of nozzle not only needs to achieve a variable cross-section design from the inlet to the complex outlet while meeting the geometric constraints of the aircraft body, but also needs to provide excellent aerodynamic performance, which is quite difficult to design.

[0004] Traditional three-dimensional variable-section nozzles are typically designed using a bidirectional streamline tracing method: first, a characteristic line method is used to create an annular reference flow field. Then, bidirectional streamline tracing is used to design a three-dimensional variable-section nozzle with the required inlet and outlet shapes. Given the nozzle inlet diameter and outlet height, the area ratio of the nozzle outlet to the inlet is an important indicator for measuring the nozzle's lateral expansion capability. A larger area ratio indicates greater lateral expansion capability. When designing a nozzle, it is often necessary to achieve maximum gas expansion within a limited length. Therefore, the nozzle must not only expand in the vertical direction, but also to a significant degree on the left and right sides. Furthermore, during the flight-engine integration process, the aircraft will also require the nozzle to have a sufficiently large maximum width to facilitate integration with the rear fuselage. Therefore, the nozzle sidewalls must also have a large lateral expansion angle.

[0005] The key dimensions of the annular reference nozzle are as follows: Figure 1 As shown. When the nozzle length, inlet height, outlet height, and lower wall expansion angle are constant, the nozzle outlet and inlet area ratio is a single-valued function of r1. At this time, the nozzle area ratio changes with r1 as shown in the following example. Figure 2 As shown in the figure, there is a maximum area ratio between the outlet and inlet of the annular reference nozzle, and this maximum value is often small, which leads to a weak lateral expansion of the streamlines in the annular reference flow field and the inability to realize the design of a three-dimensional variable cross-section nozzle with a large lateral expansion angle.

[0006] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned deficiencies of the prior art. Summary of the Invention

[0007] The purpose of this application is to provide a design method for a three-dimensional variable-cross-section unilateral expansion nozzle with a large lateral expansion angle to solve at least one problem existing in the prior art.

[0008] The technical solution of this application is:

[0009] A design method for a three-dimensional variable-section unilateral expansion nozzle with a large lateral expansion angle includes:

[0010] Step 1: Obtain nozzle aerodynamic parameters and dimensional constraint parameters, wherein the dimensional constraint parameters include nozzle upper wall length, nozzle upper wall height, nozzle lower wall length, nozzle lower wall height, nozzle inlet width, and nozzle outlet width;

[0011] Step 2: Define the nozzle sidewall as a straight line configuration and calculate the lateral expansion angle based on the nozzle upper wall length, nozzle inlet width, and nozzle outlet width;

[0012] Step 3: Define the nozzle lower wall as a straight line configuration, and calculate the lower wall expansion angle based on the nozzle lower wall length, nozzle lower wall height, and nozzle inlet width;

[0013] Step 4: Using the nozzle aerodynamic parameters, the lateral expansion angle, and the lower wall expansion angle as input, the nozzle upper wall configuration is obtained according to the shortest length nozzle theory and the unilateral expansion nozzle design method considering lateral expansion;

[0014] Step 5: Directly shorten the nozzle upper wall and the nozzle lower wall according to the length of the nozzle upper wall to obtain a reference nozzle configuration with a large lateral expansion angle. Determine whether the nozzle upper wall height of the reference nozzle configuration meets the dimensional constraint requirements. If so, output the reference nozzle configuration and proceed to step 6. If not, adjust the nozzle aerodynamic parameters and return to step 4.

[0015] Step 6. Carry out three-dimensional numerical simulation calculations for the reference nozzle configuration to obtain a three-dimensional reference flow field, thereby obtaining a nozzle inlet streamline with a specific nozzle inlet shape and a nozzle outlet streamline with a specific nozzle outlet shape. The nozzle inlet streamline and the nozzle outlet streamline are merged through a linear gradient function to obtain a three-dimensional variable-section unilateral expansion nozzle under a large lateral expansion angle with both inlet and outlet shapes meeting the requirements.

[0016] In at least one embodiment of the present application, in step 2, calculating the lateral expansion angle according to the nozzle upper wall length, the nozzle inlet width, and the nozzle outlet width includes:

[0017] Lateral expansion angle θ c for:

[0018]

[0019] Where L1 is the length of the nozzle upper wall, D is the nozzle inlet width, and W is the nozzle outlet width.

[0020] In at least one embodiment of the present application, in step 3, calculating the lower wall expansion angle according to the nozzle lower wall length, the nozzle lower wall height, and the nozzle inlet width includes:

[0021] Lower wall expansion angle δ L for:

[0022]

[0023] Among them, L2 is the length of the lower wall of the nozzle, H2 is the height of the lower wall of the nozzle, and D is the width of the nozzle inlet.

[0024] In at least one embodiment of the present application, the nozzle aerodynamic parameters include an inlet Mach number, an outlet Mach number, geometric control parameters, and a nozzle inlet airflow direction angle.

[0025] In at least one embodiment of the present application, in step five, when the nozzle upper wall height of the reference nozzle configuration does not meet the size constraint requirement, the inlet Mach number and the outlet Mach number are adjusted.

[0026] In at least one embodiment of the present application, in step six, a three-dimensional variable cross-section single-sided expansion nozzle with a large lateral expansion angle and inlet and outlet shapes that meet the requirements is obtained by a two-way streamline tracking method.

[0027] The invention has at least the following beneficial technical effects:

[0028] The design method of a three-dimensional variable-cross-section unilateral expansion nozzle with a large lateral expansion angle of the present application can design a three-dimensional variable-cross-section unilateral expansion nozzle with a large lateral expansion angle based on the given nozzle inlet aerodynamic parameters, design Mach number, inlet and outlet shapes, and nozzle external dimension requirements, so that the expansion ratio and thrust coefficient of the nozzle can be greatly improved within a limited length and height range; at the same time, the external dimensions of the nozzle fully meet the requirements of the aircraft, greatly improving the efficiency and quality of the integrated flight and engine design of hypersonic aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of an annular reference nozzle according to an embodiment;

[0030] Figure 2 is a schematic diagram of an annular reference nozzle area ratio according to an embodiment;

[0031] Figure 3 is a top view of a nozzle according to one embodiment of the present application;

[0032] Figure 4 is a cross-sectional view of a nozzle according to one embodiment of the present application;

[0033] Figure 5 This is a schematic diagram of the geometric parameters of the nozzle shape according to one embodiment of the present application;

[0034] Figure 6 Schematic diagram of nozzle flow field characteristic lines according to one embodiment of the present application;

[0035] Figure 7 is a schematic diagram of a reference nozzle configuration according to one embodiment of the present application;

[0036] Figure 8 This is a schematic diagram of nozzle inlet streamlines according to one embodiment of the present application;

[0037] Figure 9 This is a schematic diagram of the nozzle outlet streamlines of one embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be understood as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0039] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as limiting the scope of protection of this application.

[0040] The following is combined with Figures 3 to 9 This application is described in further detail.

[0041] The present application provides a design method for a three-dimensional variable-cross-section unilateral expansion nozzle with a large lateral expansion angle, comprising the following steps:

[0042] Step 1: Obtain nozzle aerodynamic parameters and dimensional constraint parameters, where the dimensional constraint parameters include nozzle upper wall length, nozzle upper wall height, nozzle lower wall length, nozzle lower wall height, nozzle inlet width, and nozzle outlet width;

[0043] Step 2: Define the nozzle sidewall as a straight line configuration and calculate the lateral expansion angle based on the nozzle upper wall length, nozzle inlet width, and nozzle outlet width;

[0044] Step 3: Define the nozzle lower wall as a straight line configuration, and calculate the lower wall expansion angle based on the nozzle lower wall length, nozzle lower wall height, and nozzle inlet width;

[0045] Step 4: Using the nozzle aerodynamic parameters, lateral expansion angle, and lower wall expansion angle as input, the nozzle upper wall configuration is obtained based on the minimum length nozzle theory and the unilateral expansion nozzle design method considering lateral expansion.

[0046] Step 5: Directly shorten the nozzle upper wall and the nozzle lower wall according to the nozzle upper wall length to obtain a reference nozzle configuration with a large lateral expansion angle. Determine whether the nozzle upper wall height of the reference nozzle configuration meets the dimensional constraint requirements. If so, output the reference nozzle configuration and proceed to step 6. If not, adjust the nozzle aerodynamic parameters and return to step 4.

[0047] Step 6. Carry out three-dimensional numerical simulation calculations for the reference nozzle configuration to obtain a three-dimensional reference flow field, thereby obtaining nozzle inlet streamlines with a specific nozzle inlet shape and nozzle outlet streamlines with a specific nozzle outlet shape. The nozzle inlet streamlines and nozzle outlet streamlines are merged through a linear gradient function to obtain a three-dimensional variable-section unilateral expansion nozzle under a large lateral expansion angle with both inlet and outlet shapes meeting the requirements.

[0048] This application presents a design method for a three-dimensional, variable-section, single-side expansion nozzle with a large lateral expansion angle. To achieve this, a three-dimensional, variable-section, single-side expansion nozzle with a large lateral expansion angle must be designed. By employing the minimum-length nozzle theory and a nozzle design method that considers lateral expansion, a three-dimensional, reference nozzle with controllable inlet and outlet dimensions can be obtained for any lateral expansion angle.

[0049] In a preferred embodiment of the present application, the nozzle design parameters are first obtained, including the nozzle aerodynamic parameters and strong dimensional constraints. Before the nozzle is designed, the dimensional requirements are determined, including the nozzle upper wall length L1, the nozzle upper wall height H1, the nozzle lower wall length L2, the nozzle lower wall height H2, the nozzle inlet width D, and the nozzle outlet width W.

[0050] When the cross-section of the nozzle side wall is a straight line, the nozzle has better performance, so the nozzle side wall is defined as a straight line configuration, such as Figure 3 As shown, the lateral expansion angle θ can be calculated based on the required nozzle upper wall length L1, nozzle inlet width D and nozzle outlet width W. c for:

[0051]

[0052] Where L1 is the length of the nozzle upper wall, D is the nozzle inlet width, and W is the nozzle outlet width.

[0053] Since the required length L2 of the nozzle lower wall is generally short in the actual design process, the section line of the nozzle lower wall is basically a straight line. In this case, the nozzle lower wall is defined as a straight line configuration. The lower wall expansion angle δ is calculated based on the nozzle lower wall length L2, the nozzle lower wall height H2 and the nozzle inlet width D. L for:

[0054]

[0055] Among them, L2 is the length of the lower wall of the nozzle, H2 is the height of the lower wall of the nozzle, and D is the width of the nozzle inlet.

[0056] The design method for a three-dimensional variable-section, single-sided expansion nozzle with a large lateral expansion angle of the present application, after obtaining the above parameters, uses the nozzle aerodynamic parameters, lateral expansion angle, and lower wall expansion angle as input, and obtains the nozzle upper wall configuration according to the minimum length nozzle theory and the single-sided expansion nozzle design method considering lateral expansion. Specifically, in the minimum length nozzle theory MLN, the shortest length nozzle is to compress the entire initial expansion section into an acute angle (pointed angle) at the throat, so the shortest length nozzle is obtained, also known as an acute-angle nozzle. The initial expansion section is compressed into a sharp point at the throat in the minimum length nozzle design theory, which greatly shortens the length of the initial expansion section. Therefore, the obtained nozzle length is about 50% shorter than the nozzle obtained using the basic characteristic line theory, and still has a high flow field quality.

[0057] The general shape of the unilateral expansion nozzle is as follows Figure 5 First, the initial expansion angle of the nozzle upper wall and the initial expansion angle of the nozzle lower wall δ need to be determined based on the inlet Mach number, outlet Mach number, geometric control parameter G, and nozzle inlet airflow direction angle ɑ. L You can assign values ​​directly, as shown below:

[0058]

[0059] Among them, δ U is the initial expansion angle of the nozzle upper wall; V E is the Prandtl-Meyer expansion angle corresponding to the expansion of the airflow from the nozzle inlet to the design outlet Mach number. The nozzle inlet airflow direction angle ɑ is limited to 0 to V E between.

[0060] Furthermore, the flow field and nozzle profile are solved by the characteristic line method, which is mainly divided into the following steps:

[0061] a. Figure 6 As shown in the figure, based on the multiple characteristic lines emitted from the upper and lower cusps of the nozzle, the flow parameters of the core area where the characteristic lines intersect are obtained by solving the two-dimensional characteristic line equation and the compatibility equation:

[0062]

[0063]

[0064] Where θ is the angle between the local velocity and the x-axis, μ is the local Mach angle, and V x is the component of the local velocity on the x-axis, c is the local sound speed, λ is the slope of the characteristic line, V y is the component of the local velocity on the y-axis, + represents the left characteristic line, and - represents the right characteristic line.

[0065] b. The characteristic line from the upper cusp passes through the core area, intersects with the straight line segment de on the lower wall, and is reflected. The reflected characteristic line intersects with the characteristic line from the upper cusp, expanding and accelerating the airflow again until the Mach number at point g is equal to the design Mach number.

[0066] c. In the two-dimensional case, the acg and egf regions are simple wave regions. The coordinates of the upper and lower walls can be obtained according to the wave elimination method or the flow conservation method, thereby obtaining the configuration of the upper and lower walls of the nozzle.

[0067] To increase the nozzle expansion area and better integrate it with the aircraft, the nozzle also requires a certain amount of lateral expansion. The design method for a unilaterally expanding nozzle that considers lateral expansion involves replacing the original two-dimensional characteristic line equation with a quasi-two-dimensional characteristic line equation that also accounts for lateral expansion. This modified design method can design the configuration of the upper and lower nozzle walls based on a given sidewall profile.

[0068] Specifically, to consider the effect of lateral expansion on the nozzle profile when designing the upper and lower nozzle profiles, a quasi-two-dimensional characteristic line theory method was adopted. Compared with the two-dimensional characteristic line method, its compatibility equation is transformed into the following form:

[0069]

[0070] Among them, V x is the component of the local velocity on the x-axis, c is the local sound speed, λ is the slope of the characteristic line, V y is the component of the local velocity on the y-axis, + represents the left characteristic line, and - represents the right characteristic line.

[0071] The function δ that controls lateral expansion is:

[0072]

[0073] The nozzle lateral expansion line is a single-valued function of x, expressed as W(x).

[0074] The flow field parameters of the internal points of the nozzle can be solved according to the quasi-two-dimensional characteristic line theory method, and then the coordinates of the nozzle wall can be solved according to the flow conservation law.

[0075] The design method of a three-dimensional variable-section single-sided expansion nozzle with a large lateral expansion angle of the present application, after determining the nozzle side wall configuration, the nozzle lower wall configuration and the nozzle upper wall configuration, directly shortens the nozzle upper wall and the nozzle lower wall according to the nozzle upper wall length to obtain a reference nozzle configuration. Due to the limitations in steps two and three, the nozzle lower wall height H2 of the reference nozzle configuration must meet the design requirements, the nozzle inlet width D and the nozzle outlet width W must meet the design requirements, and whether the nozzle upper wall height meets the design requirements needs to be judged. If it meets the requirements, the design is terminated and the reference nozzle configuration is output; if it does not meet the requirements, the design Mach number in the nozzle aerodynamic parameters is adjusted, and step four is returned to re-obtain the nozzle upper wall configuration until the nozzle upper wall length and height meet the design requirements at the same time. In one embodiment of the present application, the final reference nozzle configuration is obtained as follows Figure 7 shown.

[0076] In this embodiment, a reference flow field is designed in which the lateral expansion degree meets the requirements and the nozzle inlet and outlet are both rectangular. The reference nozzle configuration can just cover the required nozzle inlet and outlet.

[0077] Finally, a three-dimensional variable-section nozzle design is carried out. The ideal inviscid gas model is used to simulate the benchmark nozzle configuration. Then, a set of streamlines is made for the given inlet and outlet respectively. The two sets of streamlines are merged through a linear gradient function. By using the bidirectional streamline tracking method, a three-dimensional variable-section unilateral expansion nozzle with a large lateral expansion angle and an inlet and outlet shape that meet the requirements can be obtained. Figure 8-9 .

[0078] The inlet and outlet streamline coordinates are shown as follows:

[0079] (y,z)in=fin(x)

[0080] (y,z)out=fout(x)

[0081] Merged streamlines:

[0082] (y,z)=(x / L1)(y,z)in+(1-x / L1)(y,z)out

[0083] Where (y,z)in is a streamline passing through the nozzle inlet profile, (y,z)out is a streamline passing through the nozzle outlet profile, and (y,z) is a combined nozzle profile generatrix. All three are single-valued functions of x.

[0084] The design method of a three-dimensional variable-cross-section unilateral expansion nozzle with a large lateral expansion angle of the present application can realize the design of a three-dimensional variable-cross-section unilateral expansion nozzle at a large lateral expansion degree, increase the expansion degree of the gas and the nozzle thrust coefficient within a limited length, meet the requirements of the aircraft for the nozzle size, and realize the integrated design of the nozzle and the aircraft.

[0085] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A design method for a three-dimensional variable cross-section unilateral expansion nozzle with a large lateral expansion angle, characterized in that: include: Step 1: Obtain nozzle aerodynamic parameters and dimensional constraint parameters, wherein the dimensional constraint parameters include nozzle upper wall length, nozzle upper wall height, nozzle lower wall length, nozzle lower wall height, nozzle inlet width, and nozzle outlet width; Step 2: Define the nozzle sidewall as a straight line configuration and calculate the lateral expansion angle based on the nozzle upper wall length, nozzle inlet width, and nozzle outlet width; Step 3: Define the nozzle lower wall as a straight line configuration, and calculate the lower wall expansion angle based on the nozzle lower wall length, nozzle lower wall height, and nozzle inlet width; Step 4: Using the nozzle aerodynamic parameters, the lateral expansion angle, and the lower wall expansion angle as input, the nozzle upper wall configuration is obtained according to the shortest length nozzle theory and the unilateral expansion nozzle design method considering lateral expansion; Step 5: Directly shorten the nozzle upper wall and the nozzle lower wall according to the length of the nozzle upper wall to obtain a reference nozzle configuration with a large lateral expansion angle. Determine whether the nozzle upper wall height of the reference nozzle configuration meets the dimensional constraint requirements. If so, output the reference nozzle configuration and proceed to step 6. If not, adjust the nozzle aerodynamic parameters and return to step 4. Step 6. Carry out three-dimensional numerical simulation calculations for the reference nozzle configuration to obtain a three-dimensional reference flow field, thereby obtaining a nozzle inlet streamline with a specific nozzle inlet shape and a nozzle outlet streamline with a specific nozzle outlet shape. The nozzle inlet streamline and the nozzle outlet streamline are merged through a linear gradient function to obtain a three-dimensional variable-section unilateral expansion nozzle under a large lateral expansion angle with both inlet and outlet shapes meeting the requirements.

2. The design method of a three-dimensional variable cross-section single-side expansion nozzle with a large lateral expansion angle according to claim 1 is characterized in that: In step 2, the calculation of the lateral expansion angle according to the nozzle upper wall length, the nozzle inlet width, and the nozzle outlet width includes: Lateral expansion angle θ c for: Where L1 is the length of the nozzle upper wall, D is the nozzle inlet width, and W is the nozzle outlet width.

3. The design method of a three-dimensional variable cross-section single-side expansion nozzle with a large lateral expansion angle according to claim 1 is characterized in that: In step 3, the calculation of the lower wall expansion angle according to the nozzle lower wall length, the nozzle lower wall height, and the nozzle inlet width includes: Lower wall expansion angle δ L for: Among them, L2 is the length of the lower wall of the nozzle, H2 is the height of the lower wall of the nozzle, and D is the width of the nozzle inlet.

4. The design method of a three-dimensional variable cross-section single-side expansion nozzle with a large lateral expansion angle according to claim 1 is characterized in that: The nozzle aerodynamic parameters include the inlet Mach number, the outlet Mach number, geometric control parameters and the nozzle inlet airflow direction angle.

5. The design method of a three-dimensional variable cross-section single-side expansion nozzle with a large lateral expansion angle according to claim 1 is characterized in that: In step five, when the nozzle upper wall height of the reference nozzle configuration does not meet the size constraint requirement, the inlet Mach number and the outlet Mach number are adjusted.

6. The design method of a three-dimensional variable cross-section single-side expansion nozzle with a large lateral expansion angle according to claim 1 is characterized in that: In step six, a three-dimensional variable-section single-sided expansion nozzle with a large lateral expansion angle and inlet and outlet shapes that meet the requirements is obtained through the two-way streamline tracking method.

Images