A parameter optimization method for the adjustment mechanism of a double-circuit-controlled expansion nozzle

Abstract

The present application belongs to the field of aero-engines, and particularly relates to a method for optimizing parameters of a dual-loop controlled converging and expanding nozzle regulating mechanism, comprising step S1: establishing a multi-objective optimization equation of an objective function Y and a design variable X, wherein the objective function Y includes a plurality of preset objective parameters of the dual-loop controlled converging and expanding nozzle, and the design variable X includes a plurality of preset variables of the dual-loop controlled converging and expanding nozzle; step S2: determining a calculation formula of a plurality of preset objective parameters of the objective function Y; step S3: determining a constraint function of the design variable X; step S4: determining a boundary condition of the objective function Y; step S5: solving the multi-objective optimization equation; and being able to use aerodynamic loads, throats and outlet areas of a plurality of design points as input parameters, typical node loads, actuator drag force, rear body angle and exhaust area of ​​a design point as optimization targets, and quantitatively calculating the optimal solution of the converging and expanding nozzle regulating mechanism parameters for subsequent detailed structural design.

Description

Technical Field

[0001] The present application belongs to the field of aero-engines, and in particular relates to a method for optimizing parameters of a dual-circuit controlled expansion nozzle adjustment mechanism. Background Art

[0002] With the rapid development of aviation technology, the design speed and accuracy of the expansion nozzle need to meet higher requirements in order to quickly adapt to the changes in the main engine components and effectively reduce the weight of the nozzle and the actuation system. At present, there is no method for optimizing the parameters of the dual-circuit control expansion nozzle adjustment mechanism in China. It is impossible to optimize the adjustment mechanism parameters for multiple design points and multiple design goals at the same time, which is not conducive to the rapid iteration of the expansion nozzle, performance and overall parameters, and thus affects one or more indicators such as function, performance, weight, reliability, and external dimensions.

[0003] At present, there is no method for optimizing the parameters of the adjustment mechanism of the dual-circuit controlled retractable-expandable nozzle in China. The design of the adjustment mechanism parameters of the retractable-expandable nozzle relies on two-dimensional simulation software, and it is impossible to simultaneously optimize the adjustment mechanism parameters for multiple design points and multiple design objectives. This is not conducive to the rapid iteration of the retractable-expandable nozzle, performance and overall parameters, and thus affects one or several indicators such as function, performance, weight, reliability, and external dimensions. Summary of the invention

[0004] In order to solve the above problems, the present application provides a method for optimizing the parameters of a dual-circuit controlled expansion nozzle adjustment mechanism.

[0005] The double-ring controlled convergent-divergent nozzle adjustment mechanism comprises: a convergent section, an expansion section, and an outer adjustment piece; the front end of the convergent section is hinged to a third ear seat, the rear end of the convergent section is hinged to the front end of the expansion section, a position on the outside of the expansion section is hinged to a first ear seat at the front end of the outer adjustment piece through a bracket and a pull rod, and the rear end of the outside of the expansion section is hinged to a second ear seat at the rear end of the outer adjustment piece through a rotating rod; wherein an arc-shaped skeleton is connected to a position on the outside of the convergent section, and the skeleton drives the convergent section to move through rollers connected to the surface of the skeleton;

[0006] Parameter optimization methods include:

[0007] Step S1: establishing a multi-objective optimization equation of an objective function Y and a design variable X, wherein the objective function Y includes a plurality of preset target parameters of a dual-loop controlled convergent-divergent nozzle, and the design variable X includes a plurality of preset variables of a dual-loop controlled convergent-divergent nozzle;

[0008] Step S2: determining a calculation formula of a plurality of preset target parameters of the target function Y;

[0009] Step S3: Determine the constraint function of the design variable X;

[0010] Step S4: Determine the boundary conditions of the objective function Y;

[0011] Step S5: solving the multi-objective optimization equation.

[0012] Preferably, the objective function Y is specifically:

[0013] Y=[F A ,F B ,F C ,F D ,F 8 ,F 9 ,P 1 ,P 2 ,P 3 ,P 4 ,α,S c ] T ;

[0014] The design variable X is specifically:

[0015] X=[L 1 ,L 2 ,L 3 ,L 4 ,L 5 ,L 6 ,L 7 ,L 8 ,R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,H 0 ,H 1 ,H 2 ,L cs ,L es ] T ;

[0016] The multi-objective optimization equation is specifically:

[0017] Y i =f i (X), (i=1,2,3,...m);

[0018] F A -- Load of the first node A;

[0019] F B -- Second Node B load;

[0020] F C --Third node C load;

[0021] F D -- Fourth node D load;

[0022] F 8 --A8 actuator load capacity;

[0023] F 9 --A9 actuator load capacity;

[0024] P 1 --A8 actuator stroke;

[0025] P 2 --A9 actuator stroke;

[0026] α--posterior body angle;

[0027] S c --Exhaust area;

[0028] m – number of design points;

[0029] L 1 --The distance between the hinge points of the support (5) and the pull rod (6) and the hinge points of the convergence section (1) and the expansion section (4) along the direction of the expansion section (4);

[0030] L 2 -- The direction of the vertical expansion section (4), the distance between the hinge point of the bracket (5) and the tie rod (6) and the hinge point of the convergence section (1) and the expansion section (4);

[0031] L 3 --The distance between the hinge point between the bracket (5) and the pull rod (6) and the hinge point between the pull rod (6) and the first ear seat (7);

[0032] L 4 -- In the direction perpendicular to the convergence section (1), the distance between the center of the frame (2) and the hinge point between the convergence section (1) and the third ear seat (11);

[0033] L 5 - along the direction of the convergent section (1), the distance between the center of the frame (2) and the hinge point of the convergent section (1) and the third ear seat (11);

[0034] L 6 --The vertical distance from the hinge point of the second ear seat (9) and the rotating rod (10) to the outer adjustment plate (8);

[0035] L 7 - along the direction of the outer adjustment plate (8), the distance between the hinge point of the first ear seat (7) and the outer adjustment plate (8) and the hinge point of the second ear seat (9) and the rotating rod (10);

[0036] L 8 -- along the direction of the outer adjustment plate (8), the distance between the hinge point of the second ear seat (9) and the rotating rod (10) and the end of the outer adjustment plate (8);

[0037] R 1--The radius of gyration of the hinge point between the convergent section (1) and the third ear seat (11);

[0038] R 2 -- radius of the skeleton (2);

[0039] R 3 - the radius of the roller (3);

[0040] R 4 -- Radius of gyration of the hinge point between the convergent section (1) and the divergent section (4);

[0041] R 5 --The radius of gyration of the hinge point between the first ear seat (7) and the outer adjustment plate (8);

[0042] H 0 --The distance between the convergent section (1), the hinge point of the third ear seat (11) and the central axis of the engine;

[0043] H 1 - the distance between the center of the roller (3) and the center axis of the engine;

[0044] H 2 --The distance between the hinge point of the pull rod (6) and the first ear seat (7) and the central axis of the engine;

[0045] L cs -- the length of the convergent segment (1);

[0046] L es --The length of the expansion section (4).

[0047] Preferably, the calculation formula of the multiple preset target parameters of the objective function Y in step S2 is specifically:

[0048] (1)

[0049]

[0050] F C1 =-F D cos(β es +γ es ),

[0051] F C2 =F D sin(β es +γ es )-F es ,

[0052]

[0053]

[0054]

[0055] (2)

[0056]

[0057]

[0058]

[0059]

[0060] (3)

[0061] F A1 = F C1 cosβ es -F C2 sinβ es +F B cosγ cs -F cs sinδ cs ,

[0062] F A2 = F C1 sinβ es +F C2 cosβ es +F B sinγ cs -F cs cosδ cs ,

[0063] (4)F 9 = F D cosγ es ,

[0064] F 8 = F B cosγ cs ;

[0065] (5)

[0066]

[0067] (6) Solve for α;

[0068] (7)S c = πP 4 2 -S A9 ,

[0069] P3 =L 3 sin(γ es -α)+R 5 ,

[0070] P 4 =H 2 +R 5 cosα-(L 7 +L 8 )sinα;

[0071] Where: S A8 --Throat area at design point;

[0072] S A9 -- Design point outlet area;

[0073] F cs --Aerodynamic loads in the convergent section;

[0074] M cs -- Aerodynamic load moment of convergence section;

[0075] F es -- Aerodynamic loads in the expansion section;

[0076] M es -- Aerodynamic load moment of expansion section;

[0077] β es ,θ es , γ es ,θ cs , δ cs , γ cs All are algebraic expressions;

[0078] The design point is a specific flight condition and engine operating state corresponding to the aerodynamic and thermodynamic parameters and geometric dimensions of the engine and its components determined when designing the engine. It is called the design point (the engine design point may be different from the design points of its components).

[0079] Preferably, the constraint function of the design variable X includes: structure size range constraint and structure relative relationship constraint.

[0080] Preferably, the boundary conditions of the objective function Y include: boundary conditions of the drag force and node load of all design points, boundary conditions of the structural restriction points, boundary conditions of the exhaust area and the rear body angle of a certain design point, and boundary conditions of the actuator stroke of multiple design points.

[0081] Preferably, solving the multi-objective optimization equation is specifically: solving the multi-objective optimization equation based on preset weight ratios of preset objective parameters of the objective function Y.

[0082] This application proposes a method for optimizing the parameters of the adjustment mechanism of a dual-ring controlled expansion nozzle, taking typical node loads, actuator drag force, rear body angle and exhaust area of ​​the design point as optimization targets, and based on the weight ratio of each optimization target in the design requirements, quantitatively calculating and optimizing the optimal solution of the adjustment mechanism parameters to provide a basis for subsequent detailed structural design and product transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 It is a schematic diagram of the adjustment mechanism of the retracting and expanding nozzle;

[0084] Figure 2 It is a schematic diagram of the parameters of the expansion nozzle adjustment mechanism;

[0085] Among them, 1-convergence section; 2-skeleton; 3-roller; 4-expansion section, 5-bracket; 6-pull rod; 7-first ear seat; 8-outer adjustment plate; 9-second ear seat; 10-rotating rod; 11-third ear seat. DETAILED DESCRIPTION

[0086] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation 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 implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0087] The present application provides a method for optimizing the parameters of a dual-circuit controlled expansion nozzle adjustment mechanism.

[0088] like Figure 1 As shown, the double-ring controlled convergent-divergent nozzle adjustment mechanism comprises: a convergent section (1), an expansion section (4), and an outer adjustment plate (8); the front end of the convergent section (1) is hinged to a third ear seat (11), the rear end of the convergent section (1) is hinged to the front end of the expansion section (4), a position on the outside of the expansion section (4) is hinged to a first ear seat (7) provided at the front end of the outer adjustment plate (8) through a bracket (5) and a pull rod (6), and the rear end of the outside of the expansion section (4) is hinged to a second ear seat (9) provided at the rear end of the outer adjustment plate (8) through a rotating rod (10); wherein, a position on the outside of the convergent section (1) is connected to an arc-shaped skeleton (2), and the skeleton (2) drives the convergent section (1) to move through rollers (3) connected to its surface contact; the parameter optimization method comprises:

[0089] Step S1: establishing a multi-objective optimization equation of an objective function Y and a design variable X, wherein the objective function Y includes a plurality of preset target parameters of a dual-loop controlled convergent-divergent nozzle, and the design variable X includes a plurality of preset variables of a dual-loop controlled convergent-divergent nozzle;

[0090] Step S2: determining a calculation formula of a plurality of preset target parameters of the target function Y;

[0091] Step S3: Determine the constraint function of the design variable X;

[0092] Step S4: Determine the boundary conditions of the objective function Y;

[0093] Step S5: solving the multi-objective optimization equation.

[0094] In some optional implementations, the objective function Y is specifically, the parameter relationship is as follows Figure 2 As shown:

[0095] Y=[F A ,F B ,F C ,F D ,F 8 ,F 9 ,P 1 ,P 2 ,P 3 ,P 4 ,α,S c ] T ;

[0096] The design variable X is specifically:

[0097] X=[L 1 ,L 2 ,L 3 ,L 4 ,L 5 ,L 6 ,L 7 ,L 8 ,R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,H 0 ,H 1 ,H 2 ,L cs ,L es ] T ;

[0098] The multi-objective optimization equation is specifically:

[0099] Y i =f i(X), (i=1,2,3,...m);

[0100] F A -- Load of the first node A;

[0101] F B -- Second Node B load;

[0102] F C --Third node C load;

[0103] F D -- Fourth node D load;

[0104] F 8 --A8 actuator load capacity;

[0105] F 9 --A9 actuator load capacity;

[0106] P 1 --A8 actuator stroke;

[0107] P 2 --A9 actuator stroke;

[0108] α--posterior body angle;

[0109] S c --Exhaust area;

[0110] m – number of design points;

[0111] L 1 --The distance between the hinge points of the support (5) and the pull rod (6) and the hinge points of the convergence section (1) and the expansion section (4) along the direction of the expansion section (4);

[0112] L 2 -- The direction of the vertical expansion section (4), the distance between the hinge point of the bracket (5) and the tie rod (6) and the hinge point of the convergence section (1) and the expansion section (4);

[0113] L 3 --The distance between the hinge point between the bracket (5) and the pull rod (6) and the hinge point between the pull rod (6) and the first ear seat (7);

[0114] L 4 -- In the direction perpendicular to the convergence section (1), the distance between the center of the frame (2) and the hinge point between the convergence section (1) and the third ear seat (11);

[0115] L 5 - along the direction of the convergent section (1), the distance between the center of the frame (2) and the hinge point of the convergent section (1) and the third ear seat (11);

[0116] L 6--The vertical distance from the hinge point of the second ear seat (9) and the rotating rod (10) to the outer adjustment plate (8);

[0117] L 7 - along the direction of the outer adjustment plate (8), the distance between the hinge point of the first ear seat (7) and the outer adjustment plate (8) and the hinge point of the second ear seat (9) and the rotating rod (10);

[0118] L 8 -- along the direction of the outer adjustment plate (8), the distance between the hinge point of the second ear seat (9) and the rotating rod (10) and the end of the outer adjustment plate (8);

[0119] R 1 --The radius of gyration of the hinge point between the convergent section (1) and the third ear seat (11);

[0120] R 2 -- radius of the skeleton (2);

[0121] R 3 - the radius of the roller (3);

[0122] R 4 -- Radius of gyration of the hinge point between the convergent section (1) and the divergent section (4);

[0123] R 5 --The radius of gyration of the hinge point between the first ear seat (7) and the outer adjustment plate (8);

[0124] H 0 --The distance between the convergent section (1), the hinge point of the third ear seat (11) and the central axis of the engine;

[0125] H 1 - the distance between the center of the roller (3) and the center axis of the engine;

[0126] H 2 --The distance between the hinge point of the pull rod (6) and the first ear seat (7) and the central axis of the engine;

[0127] L cs -- the length of the convergent segment (1);

[0128] L es --The length of the expansion section (4).

[0129] In some optional implementations, the calculation formulas for the multiple preset target parameters of the target function Y in step S2 are specifically:

[0130] (1)

[0131]

[0132] F C1=-F D cos(β es +g es ),

[0133] F C2 =F D sin(β es +g es )-F es ,

[0134]

[0135]

[0136]

[0137] (2)

[0138]

[0139]

[0140]

[0141]

[0142] (3)

[0143] F A1 =F C1 cosβ es -F C2 sinβ es +F B cosγ cs -F cs sind cs ,

[0144] F A2 =F C1 sinβ es +F C2 cosβ es +F B sing cs -F cs cosδ cs ,

[0145] (4)F 9 =F D cosγ es ,

[0146] F 8 =F B cosγcs ;

[0147] (5)

[0148]

[0149] (6) Solve for α;

[0150] (7)S c =πP 4 2 -S A9 ,

[0151] P 3 =L 3 sin(γ es -α)+R 5 ,

[0152] P 4 =H 2 +R 5 cosα-(L 7 +L 8 )sinα;

[0153] Where: S A8 --Throat area at design point;

[0154] S A9 -- Design point outlet area;

[0155] F cs --Aerodynamic loads in the convergent section;

[0156] M cs -- Aerodynamic load moment of convergence section;

[0157] F es -- Aerodynamic loads in the expansion section;

[0158] M es -- Aerodynamic load moment of expansion section;

[0159] β es ,θ es , γ es ,θ cs , δ cs , γ cs All are algebraic expressions.

[0160] Determine the constraint function of the design variable X

[0161] g i (X)≥0h i (X) = 0 (i = 1, 2, 3, ... m)

[0162] (1) Structural size range, such as L 1 -10≥0, R 4 -0.002=0,0.11-L 2 ≥0;

[0163] (2) Structural relative relationship, such as L es -L 1 ≥0,L 6 -R 5 ≥0;

[0164] 5. Determine the boundary conditions of the objective function Y

[0165] p(Y i )≥0q(Y i )=0(i=1,2,3,...m)

[0166] (1) All design points, drag forces, node loads, such as 4000-F 8 ≥0,10000-F C ≥ 0;

[0167] (2) Structural restriction points, such as S A8 Maximum, corresponding S A9 Minimum: P 3 -K≥0, S A8 Maximum, corresponding S A9 Maximum: α ≥ 0, P 2 +R 5 sinα+(L 7 +L 8 )cosα-(L cs cosδ cs -R 1 sinδ cs +L es cosβ es )≥0;

[0168] Where: K is a constant, designed according to actual needs, generally K≥25;

[0169] (3) At a certain design point, exhaust area, rear body angle, such as S A8 The minimum corresponding S A9 Minimum: S c -0.03≥0, a certain state point α-0.2≥0

[0170] (4) Multiple design points, actuator stroke, such as S A8 Minimum P 1-1 With S A8 Maximum P 1-2 :P 1-2 -P 1-1 -0.008≥0.

[0171] In some optional implementations, solving the multi-objective optimization equation is specifically: solving the multi-objective optimization equation based on preset weight ratios of preset objective parameters of the objective function Y.

[0172] This application proposes a method for optimizing the parameters of the adjustment mechanism of a dual-ring controlled expansion nozzle, taking typical node loads, actuator drag force, rear body angle and exhaust area of ​​the design point as optimization targets, and based on the weight ratio of each optimization target in the design requirements, quantitatively calculating and optimizing the optimal solution of the adjustment mechanism parameters to provide a basis for subsequent detailed structural design and product transformation.

[0173] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for optimizing the parameters of a dual-circuit controlled expansion nozzle adjustment mechanism. The double-ring controlled expansion nozzle adjustment mechanism comprises: A convergent section (1), an expansion section (4), and an outer adjustment plate (8); the front end of the convergent section (1) is hinged to a third ear seat (11), the rear end of the convergent section (1) is hinged to the front end of the expansion section (4), a position on the outside of the expansion section (4) is hinged to a first ear seat (7) at the front end of the outer adjustment plate (8) through a bracket (5) and a pull rod (6), and the rear end of the outside of the expansion section (4) is hinged to a second ear seat (9) at the rear end of the outer adjustment plate (8) through a rotating rod (10); wherein an arc-shaped skeleton (2) is connected to a position on the outside of the convergent section (1), and the skeleton (2) drives the convergent section (1) to move through rollers (3) connected to its surface contact; Characterized in that the parameter optimization method comprises: Step S1: establishing a multi-objective optimization equation of an objective function Y and a design variable X, wherein the objective function Y includes a plurality of preset target parameters of a dual-loop controlled convergent-divergent nozzle, and the design variable X includes a plurality of preset variables of a dual-loop controlled convergent-divergent nozzle; Step S2: determining a calculation formula of a plurality of preset target parameters of the target function Y; Step S3: Determine the constraint function of the design variable X; Step S4: Determine the boundary conditions of the objective function Y; Step S5: solving the multi-objective optimization equation; The objective function Y is specifically: Y=[F A ,F B ,F C ,F D ,F8,F9,P1,P2,P3,P4,α,S c ] T ; The design variable X is specifically: <h2 style=";text-align:left;direction:ltr">X=[L1,L2,L3,L4,L5,L6,L7,L8,R1,R2,R3,R4,R5,H0,H1,H2,L<h2 style=";text-align:left;direction:ltr"> cs <h2 style=";text-align:left;direction:ltr"> ,L<h2 style=";text-align:left;direction:ltr"> es <h2 style=";text-align:left;direction:ltr"> ]<h2 style=";text-align:left;direction:ltr"> T <h2 style=";text-align:left;direction:ltr"> ; The multi-objective optimization equation is specifically: Y i =f i (X),(i=1,2,3,...m); F A -- Load of the first node A; F B -- Second Node B load; F C --Third node C load; F D -- Fourth node D load; F8--A8 actuator load; F9--A9 actuator load; P1--A8 actuator stroke; P2--A9 actuator stroke; P3--The vertical distance from the hinge point of the bracket (5) and the pull rod (6) to the outer adjustment plate (8); P4 - vertical distance from the outlet of the outer adjustment plate (8) to the center axis of the nozzle; α--posterior body angle; S c --Exhaust area; m – the number of design points; L1 - the distance between the hinge point of the bracket (5) and the tie rod (6) and the hinge point of the convergence section (1) and the expansion section (4) along the direction of the expansion section (4); L2--the distance between the hinge point of the bracket (5) and the tie rod (6) and the hinge point of the convergence section (1) and the expansion section (4) in the direction perpendicular to the expansion section (4); L3--the distance between the hinge point of the bracket (5) and the tie rod (6) and the hinge point of the tie rod (6) and the first ear seat (7); L4--the distance between the center of the circle of the frame (2) and the hinge point of the convergent section (1) and the third ear seat (11), in the direction perpendicular to the convergent section (1); L5 - the distance between the center of the frame (2) and the hinge point between the convergent section (1) and the third ear seat (11) along the direction of the convergent section (1); L6--the vertical distance from the hinge point of the second ear seat (9) and the rotating rod (10) to the outer adjustment plate (8); L7--the distance between the hinge point of the first ear seat (7) and the outer adjustment plate (8) and the hinge point of the second ear seat (9) and the rotating rod (10) along the direction of the outer adjustment plate (8); L8--the distance between the hinge point of the second ear seat (9) and the rotating rod (10) and the end of the outer adjustment plate (8) along the direction of the outer adjustment plate (8); R1 - the radius of gyration of the hinge point between the convergent section (1) and the third ear seat (11); R2 - the radius of the frame (2); R3 – radius of roller (3); R4 - the radius of rotation of the hinge point between the convergent section (1) and the expansion section (4); R5 - the radius of rotation of the hinge point between the first ear seat (7) and the outer adjustment plate (8); path; H0--Convergence section (1), third ear seat (11) hinge point and engine center The distance between the axes; H1 - the distance between the center of the roller (3) and the center axis of the engine; H2--Tie rod (6), first ear seat (7) hinge point and engine center axis The distance of the line; L cs -- the length of the convergent segment (1); L es - the length of the expansion section (4); The calculation formula of the multiple preset target parameters of the target function Y in step S2 is specifically: (1) (2) F A1 =F C1 cosβ es -F C2 sinβ es +F B cosγ cs -F cs sinδ cs , F A2 =F C1 sinβ es +F C2 cosβ es +F B sinγ cs -F cs cosδ cs , (4)F9=F D cosγ es , F8=F B cosγ cs ; (5) (6) Solve for α; (7)S c =πP4 2 -S A9 , P3=L3sin(γ es -a)+R5, P4=H2+R5cosα-(L7+L8)sinα; Where: S A8 --Throat area at design point; S A9 -- Design point outlet area; F cs -- Aerodynamic loads in the convergent section; M cs -- Aerodynamic load moment of convergence section; F es -- Aerodynamic loads in the expansion section; M es -- Aerodynamic load moment of expansion section; β es ,θ es , γ es ,θ cs , δ cs , γ cs All are algebraic expressions.

2. The method for optimizing the parameters of the dual-circuit controlled expansion nozzle adjustment mechanism according to claim 1, characterized in that: The constraint function of the design variable X includes: structure size range constraint and structure relative relationship constraint.

3. The method for optimizing parameters of the dual-circuit controlled expansion nozzle adjustment mechanism according to claim 1, characterized in that: The boundary conditions of the objective function Y include: boundary conditions of drag force and node load of all design points, boundary conditions of structural restriction points, boundary conditions of exhaust area and rear body angle of a certain design point, and boundary conditions of actuator stroke of multiple design points.

4. The method for optimizing parameters of the dual-circuit controlled expansion nozzle adjustment mechanism according to claim 1, characterized in that: Solving the multi-objective optimization equation specifically includes: solving the multi-objective optimization equation based on the preset weight ratios of the preset objective parameters of the objective function Y.

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