Nacelle wind tunnel test model for rotation flutter analysis and simulation verification method

Abstract

The invention belongs to the field of wind tunnel tests, and relates to a nacelle wind tunnel test model for rotation flutter analysis and a simulation verification method. The wind tunnel test model is designed according to a helicopter nacelle and comprises a fuselage model, a wing model, a nacelle model, a rotor wing model, a nacelle rotor wing connection model and a nacelle wing connection model which are rigidly installed on a wind tunnel wall. Wing models are mounted on the fuselage model; the nacelle rotor wing connection model is used for connecting the rotor wing model and the nacelle model; the nacelle rotor wing connecting model is arranged in the nacelle model, and the nacelle rotor wing connecting model and the nacelle model are arranged into a whole or rigidly connected; the nacelle wing connection model is connected with the wing model through bolts; the nacelle rotor connection model is provided with two bearing seats used for assembling a rotor shaft, and a mass block is installed between the two bearing seats.

Description

Technical Field

[0001] The invention belongs to the field of wind tunnel tests and relates to a nacelle wind tunnel test model and a simulation verification method for rotation flutter analysis. Background Art

[0002] The tilt-rotor aircraft consists of a fuselage, wings, nacelles and rotors. The rotors are installed on the nacelles at both ends of the wings. The nacelles rotate around the tilt hinges to achieve dynamic conversion between helicopter, fixed-wing aircraft and tilt-transition flight modes. There is a non-negligible gyro flutter stability problem between the rotors, nacelles and elastic wings installed on the nacelles of the tilt-rotor aircraft. Once gyro flutter instability occurs, it seriously affects the safety of the tilt-rotor aircraft. At present, there is no model experience or wind tunnel test experience for the analysis of the gyro flutter stability of the rotor-nacelle-wing coupling system of the tilt-rotor aircraft in China.

[0003] As the supporting structure of the rotor, the nacelle's connection stiffness, mass and other factors directly affect the gyration flutter stability of the rotor-nacelle-wing coupling system of the tiltrotor aircraft. The rotor, main reducer, engine, tilt mechanism and other large-mass equipment are installed in the nacelle at the end of the wing, together forming the core tilting part of the tiltrotor aircraft. However, many large-mass equipment may have changes in the weight and center of gravity of the nacelle due to their own design, processing or assembly of the whole machine in various links such as planning, design, processing, delivery, and assembly, which directly affects the dynamic characteristics of the wing and further affects the gyration flutter stability of the rotor-nacelle-wing coupling system. Therefore, it is necessary to analyze the influence of the nacelle connection stiffness, weight and center of gravity on the gyration flutter stability of the tiltrotor aircraft in the early stage of model development, and ensure the flight safety of the model through rigorous verification research. Summary of the invention

[0004] Purpose of the invention: This method is used in the current domestic tilt-rotor aircraft rotation flutter wind tunnel test research, and provides guidance for the tilt-rotor aircraft rotation flutter analysis and nacelle design.

[0005] Technical solution:

[0006] In a first aspect, a nacelle wind tunnel test model for gyroscopic flutter analysis is provided, designed according to a helicopter nacelle, comprising:

[0007] The fuselage model, wing model, nacelle model, rotor model, nacelle-rotor connection model, and nacelle-wing connection model are rigidly mounted on the wind tunnel wall;

[0008] The wing model is installed on the fuselage model; the nacelle rotor connection model is used to connect the rotor model and the nacelle model;

[0009] A nacelle rotor connection model is arranged inside the nacelle model, and the nacelle rotor connection model and the nacelle model are arranged to be integrated or rigidly connected; the nacelle wing connection model is connected to the wing model by bolts;

[0010] Two bearing seats for assembling the rotor shaft are arranged on the nacelle rotor connection model, and a mass block is installed between the two bearing seats.

[0011] Furthermore, the center of gravity of the mass block is designed to be adjustable axially and laterally. The center of gravity heading parameter of the nacelle is changed by moving the mass block axially along the rotor shaft between the two bearing seats, and the lateral center of gravity parameter of the adjustable nacelle is changed by adjusting the lateral center of gravity of the mass block itself.

[0012] Furthermore, the mass block is designed to be a weight-adjustable type or a combination of multiple mass blocks, and the weight parameter of the adjustable nacelle can be changed by changing the weight of the mass block.

[0013] In a second aspect, a simulation verification method for rotary flutter analysis is provided, comprising:

[0014] Based on the requirement of adjustable key parameters such as nacelle and wing connection stiffness, nacelle weight, center of gravity, etc., the wind tunnel test model of the nacelle used for the above-mentioned rotation flutter analysis is designed;

[0015] Based on the nacelle wind tunnel test model used for rotation flutter analysis, a rotation flutter simulation analysis model of the wind tunnel test model is established, and the rotation flutter simulation analysis of the nacelle wind tunnel test model used for rotation flutter analysis is carried out;

[0016] Based on the nacelle wind tunnel test model used for rotation flutter analysis and the wind tunnel test conditions determined by simulation analysis, a wind tunnel blowing test was carried out to determine the rotation flutter stability of the wind tunnel test model under different conditions;

[0017] Compare the gyro flutter stability and simulation analysis results of the wind tunnel test model under different working conditions to verify the gyro flutter simulation analysis method of the wind tunnel test model of the rotor-nacelle-wing coupling system;

[0018] Based on the rotational flutter simulation analysis method, a rotational flutter simulation analysis model of the rotor-nacelle-wing coupling system of the tiltrotor prototype is established, and the rotational flutter stability analysis is carried out.

[0019] Furthermore, the method further comprises:

[0020] The gyro flutter stability of the tiltrotor aircraft with different nacelle and wing connection stiffness, nacelle weight and center of gravity is studied by using the gyro flutter simulation analysis model of the rotor-nacelle-wing coupling system of the tiltrotor prototype.

[0021] Furthermore, based on the nacelle wind tunnel test model for rotation flutter analysis, a rotation flutter simulation analysis model of the wind tunnel test model is established, and the rotation flutter simulation analysis of the nacelle wind tunnel test model for rotation flutter analysis is carried out, including:

[0022] Establish a rotation flutter simulation analysis model of the nacelle wind tunnel test model used for rotation flutter analysis, and respectively establish simulation analysis models of the fuselage model, wing model, nacelle model, and rotor model of the wind tunnel test model;

[0023] The multi-point constraint unit RBE3 is used to simulate the connection between the mass point and the structure, the solid unit is used to simulate the nacelle wing connection model, and the multi-point constraint unit RBE2 is used to simulate the bolt rigid connection. An adjustable nacelle finite element simulation analysis model is established, and the unit properties of the multi-point constraint unit RBE3 simulating the mass block are adjusted. Based on the modal analysis method, the influence of the mass block on the dynamic characteristics of the test model is studied, and the corresponding nacelle weight and center of gravity wind tunnel test conditions are determined.

[0024] The spring unit is used to simulate the connection stiffness between the nacelle and the wing, and the properties of the spring unit are adjusted. Based on the modal analysis method, the influence of the connection stiffness between the nacelle and the wing on the dynamic characteristics of the test model is studied, and the corresponding wind tunnel test conditions of the connection stiffness between the nacelle and the wing are determined.

[0025] The wing modal analysis results are input into the rotation flutter simulation analysis model to study the effects of the nacelle-wing connection stiffness, nacelle weight, center of gravity and other parameters on the rotation flutter stability of the test model in preparation for comparison with the wind tunnel test data.

[0026] Furthermore, based on the rotation flutter simulation analysis method, a rotation flutter simulation analysis model of the rotor-nacelle-wing coupling system of the tiltrotor prototype is established, and the rotation flutter stability analysis is carried out, including:

[0027] Based on the prototype size and aeroelastic analysis method of the tiltrotor aircraft, the prototype rotor model, wing model, and aerodynamic load analysis model are established to form a simulation analysis model for the rotation flutter of the prototype rotor-nacelle-wing coupling system.

[0028] The flutter analysis module is used to analyze the gyroscopic stability of the tiltrotor aircraft and solve the gyroscopic flutter stability of the tiltrotor aircraft rotor-nacelle-wing coupling system;

[0029] Determine the gyroscopic flutter stability of the tiltrotor aircraft rotor-nacelle-wing coupled system.

[0030] Furthermore, the point where the modal damping ratio is equal to 0 is the critical point, the tiltrotor aircraft is in a critical stable state of rotation flutter, and the corresponding forward flight speed is the critical speed of rotation flutter of the tiltrotor aircraft. Under the condition, when the modal damping ratio is positive, the analyzed tiltrotor aircraft does not have the risk of rotation flutter; when the modal damping ratio is negative, the analyzed tiltrotor aircraft has the risk of rotation flutter.

[0031] Beneficial effects: The present invention adopts engineering design and applies the nacelle design method for rotation flutter wind tunnel test in a blank field. Taking the rotation flutter stability system problem of the rotor-nacelle-wing coupling system and its wind tunnel test as the background, an adjustable nacelle design method for rotation flutter wind tunnel test is invented, which is used to study the influence of different nacelle support stiffness on the rotation flutter coupling characteristics between the rotor and the wing in the wind tunnel test, avoids increasing the risk of subsequent design status, effectively guides the design in the initial development stage, and fills the blank of wind tunnel test research in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the design of the nacelle wind tunnel test model.

[0033] Figure 2 This is a graph showing how damping varies with forward flight speed.

[0034] Figure 3 Flowchart of the simulation validation method for rotary flutter analysis. DETAILED DESCRIPTION

[0035] The present invention provides a simulation verification method for rotary flutter analysis, such as Figure 3 As shown, including:

[0036] Step 1: Design a wind tunnel test model for the rotor-nacelle-wing coupling system based on the adjustable requirements of key parameters such as the nacelle and wing connection stiffness, nacelle weight, and center of gravity;

[0037] a) According to the prototype size and dynamic scaling criteria of the tiltrotor aircraft, a wind tunnel test model of the rotor-nacelle-wing coupling system applicable to the tiltrotor aircraft is conducted, and the weight, center of gravity, and connection stiffness of the nacelle and wing of the test model are designed to be adjustable structures;

[0038] b) The rotor-nacelle-wing coupling system wind tunnel test model includes a fuselage model, a wing model, a nacelle model, a rotor model, a nacelle-rotor connection model, and a nacelle-wing connection model rigidly mounted on the wind tunnel wall;

[0039] c) designing a nacelle-rotor connection model inside the nacelle, wherein the nacelle-rotor connection model is integrated with the nacelle or rigidly connected to the nacelle and is fixedly installed inside the nacelle;

[0040] d) Design two bearing seats on the nacelle rotor connection model to assemble the rotor shaft, and install a mass block between the two bearing seats;

[0041] e) The weight of the mass block is designed to be an adjustable weight or a combination of multiple mass blocks, and the weight parameter of the adjustable nacelle is changed by changing the weight of the mass block;

[0042] f) The center of gravity of the mass block is designed to be adjustable in the axial and lateral directions. The center of gravity heading parameter of the nacelle is changed by moving the mass block along the axial direction of the rotor shaft between the two bearing seats. The lateral center of gravity of the adjustable nacelle is changed by adjusting the lateral center of gravity of the mass block itself.

[0043] g) The weight and center of gravity parameters of the adjustable nacelle can be changed by changing the weight and center of gravity combination of the mass block;

[0044] h) the nacelle-wing connection model is designed to be one or more connection parts with adjustable stiffness, and the nacelle-wing connection model is connected to the wing by bolts;

[0045] i) The connection stiffness between the nacelle and wing connection model and the wing is changed by adjusting the stiffness of the nacelle and wing connection model, the material or the number of bolts, so as to achieve parameter change of the connection stiffness between the nacelle and wing.

[0046] Step 2: Based on the designed tiltrotor aircraft rotation flutter wind tunnel test model, a rotation flutter simulation analysis model of the wind tunnel test model is established, and a simulation analysis of the wind tunnel test model of the rotor-nacelle-wing coupling system is carried out;

[0047] a) Establishing a gyroscopic flutter simulation analysis model of a wind tunnel test model of a rotor-nacelle-wing coupling system, and respectively establishing simulation analysis models of a fuselage model, a wing model, a nacelle model, and a rotor model of the wind tunnel test model;

[0048] b) Multi-point constraint unit RBE3 is used to simulate the connection between the mass point and the structure, the solid unit simulates the nacelle wing connection model, and the multi-point constraint unit RBE2 simulates the bolt rigid connection. An adjustable nacelle finite element simulation analysis model is established, and the unit properties of the multi-point constraint unit RBE3 simulating the mass block are adjusted. Based on the modal analysis method, the influence of the mass block on the dynamic characteristics of the test model is studied, and the corresponding nacelle weight and center of gravity wind tunnel test conditions are determined;

[0049] c) The nacelle-wing connection stiffness is simulated by spring units, the spring unit properties are adjusted, and based on the modal analysis method, the influence of the nacelle-wing connection stiffness on the dynamic characteristics of the test model is studied, and the corresponding nacelle-wing connection stiffness wind tunnel test conditions are determined;

[0050] d) Input the wing modal analysis results into the gyro flutter simulation analysis model to study the effects of the nacelle-wing connection stiffness, nacelle weight, center of gravity and other parameters on the gyro flutter stability of the test model in preparation for comparison with the wind tunnel test data.

[0051] Step 3: Based on the designed tiltrotor aircraft gyro flutter wind tunnel test model and the wind tunnel test conditions determined by simulation analysis, a wind tunnel blowing test is carried out to determine the gyro flutter stability of the wind tunnel test model under different conditions;

[0052] a) Adjust the wind tunnel test model to realize wind tunnel test conditions such as nacelle-wing connection stiffness, nacelle weight, center of gravity, etc.;

[0053] b) Carry out wind tunnel blowing test for each test condition;

[0054] c) Determine the stability of the rotational flutter under different working conditions based on the wind tunnel test results

[0055] d) Compare with the simulation analysis results of the fourth step to verify the rotation flutter simulation analysis method of the tiltrotor aircraft rotation flutter wind tunnel test model.

[0056] Step 4: Based on the rotation flutter simulation analysis method verified by the tiltrotor prototype and wind tunnel test, a rotation flutter simulation analysis model for the rotor-nacelle-wing coupling system is established to carry out the rotation flutter stability analysis;

[0057] a) Based on the size of the tiltrotor prototype and the aeroelastic mechanics analysis method, the rotor model, wing model and aerodynamic load analysis model of the tiltrotor are established respectively to form a rotation flutter simulation analysis model of the rotor-nacelle-wing coupling system;

[0058] b) Use the flutter analysis module to analyze the gyroscopic stability of the tiltrotor aircraft and solve the gyroscopic flutter characteristic value of the tiltrotor aircraft rotor-nacelle-wing coupling system;

[0059] c) Determine the gyro flutter stability of the tiltrotor aircraft rotor-nacelle-wing coupling system. The point where the modal damping ratio is equal to 0 is the critical point. The analyzed tiltrotor aircraft is in a critical gyro flutter stability state. The corresponding forward flight speed is the tiltrotor aircraft gyro flutter critical speed. When the modal damping ratio is positive, the analyzed tiltrotor aircraft does not have the risk of gyro flutter; when the modal damping ratio is negative, the analyzed tiltrotor aircraft has the risk of gyro flutter;

[0060] Step 5: Using the established tiltrotor aircraft rotation flutter simulation analysis model, the tiltrotor aircraft rotation flutter stability with different nacelle and wing connection stiffness, nacelle weight, and center of gravity is studied, and the rotation flutter simulation analysis model is modified based on the wind tunnel test results;

[0061] a) Based on the tiltrotor aircraft rotation flutter simulation analysis model established in the fourth step, according to the dynamics reduction criterion, determine the actual data of the nacelle and wing connection stiffness, nacelle weight, center of gravity and other data corresponding to the nacelle and wing connection stiffness, nacelle weight, center of gravity in the test;

[0062] b) Study the gyro flutter stability of the tiltrotor aircraft under the actual data of the nacelle and wing connection stiffness, nacelle weight, and center of gravity, analyze the gyro flutter stability, and modify the established tiltrotor aircraft gyro flutter simulation analysis model based on the wind tunnel test results;

[0063] Based on the revised tiltrotor aircraft rotation flutter simulation analysis model, during the model development process, the model is iteratively updated in real time according to the actual conditions such as the changes in the stiffness of the connection between the nacelle and the wing, the weight of large-mass equipment such as the engine, main reducer, tilt mechanism, and center of gravity in the nacelle, and the corresponding rotation flutter stability analysis is carried out to strictly verify that the designed tiltrotor aircraft does not have rotation flutter instability problems within the flight envelope, thereby ensuring the safety of the model.

[0064] The present invention provides a simulation verification method for rotary flutter analysis, comprising:

[0065] Step 1: Design a wind tunnel test model for the rotor-nacelle-wing coupling system based on the adjustable requirements of key parameters such as the nacelle and wing connection stiffness, nacelle weight, and center of gravity;

[0066] a) According to the prototype size and dynamic scaling criteria of the tiltrotor aircraft, a wind tunnel test model of the rotor-nacelle-wing coupling system suitable for the tiltrotor aircraft is conducted, and the weight, center of gravity, and connection stiffness of the nacelle and wing of the nacelle model 4 of the wind tunnel test are designed to be an adjustable structure;

[0067] b) Figure 1 The rotor-nacelle-wing coupling system wind tunnel test model includes a fuselage model 2 rigidly mounted on a wind tunnel wall 1, a wing model 3, a nacelle model 4, a rotor model 5, a nacelle-rotor connection model 6, and a nacelle-wing connection model 7;

[0068] c) a nacelle rotor connection model 6 is designed inside the nacelle 4, the nacelle rotor connection model 6 is integrated with the nacelle or rigidly connected to the nacelle, and is fixedly installed inside the nacelle 4;

[0069] d) Two bearing seats 62 are designed on the nacelle rotor connection model 6 to assemble the rotor shaft 61, and a mass block 63 is installed between the two bearing seats;

[0070] e) The weight of the mass block 63 is designed to be a weight-adjustable type or a combination of multiple mass blocks, and the weight parameter of the adjustable nacelle is changed by changing the weight of the mass block 63;

[0071] f) The center of gravity of the mass block 63 is designed to be adjustable in the axial and lateral directions. The center of gravity heading parameter of the nacelle is changed by axially moving the mass block 63 along the rotor shaft 61 between the two bearing seats 62. The lateral center of gravity of the adjustable nacelle is changed by adjusting the lateral center of gravity of the mass block 63 itself.

[0072] g) By combining the weight and center of gravity of the mass block 63, the weight and center of gravity of the adjustable nacelle are changed;

[0073] h) the nacelle-wing connection model 7 is designed to be one or more connection parts with adjustable stiffness, and the nacelle-wing connection model 7 is connected to the wing by bolts 71;

[0074] i) By adjusting the stiffness of the nacelle-wing connection model 7 and the material or number of the adjusting bolts 71, the connection stiffness of the nacelle-wing connection model 7 and the wing is changed, so as to change the connection stiffness parameters of the nacelle model 4 and the wing model 3.

[0075] Step 2: Based on the designed tiltrotor aircraft rotation flutter wind tunnel test model, a rotation flutter simulation analysis model of the wind tunnel test model is established, and a simulation analysis of the wind tunnel test model of the rotor-nacelle-wing coupling system is carried out;

[0076] a) establishing a gyroscopic flutter simulation analysis model of a wind tunnel test model of a rotor-nacelle-wing coupling system, and establishing simulation analysis models of a fuselage model 2, a wing model 3, a nacelle model 4, and a rotor model 5 of the wind tunnel test model respectively;

[0077] b) Using the connection between the mass point and the structure of the multi-point constraint unit RBE3, the solid unit simulates the connection model 7 between the nacelle and the wing, and the multi-point constraint unit RBE2 simulates the rigid connection of the bolts, an adjustable nacelle finite element simulation analysis model is established, and the unit properties of the multi-point constraint unit RBE3 simulating the mass block 63 are adjusted. Based on the modal analysis method, the influence of the mass block 63 on the dynamic characteristics of the test model is studied, and the corresponding nacelle weight and center of gravity wind tunnel test conditions are determined;

[0078] c) The nacelle-wing connection stiffness is simulated by spring units, the spring unit properties are adjusted, and based on the modal analysis method, the influence of the nacelle-wing connection stiffness on the dynamic characteristics of the test model is studied, and the corresponding nacelle-wing connection stiffness wind tunnel test conditions are determined;

[0079] d) Input the wing modal analysis results into the gyro flutter simulation analysis model to study the effects of the nacelle-wing connection stiffness, nacelle weight, center of gravity and other parameters on the gyro flutter stability of the test model.

[0080] For comparison with wind tunnel test data.

[0081] Step 3: Based on the designed tiltrotor aircraft gyro flutter wind tunnel test model and the wind tunnel test conditions determined by simulation analysis, a wind tunnel blowing test is carried out to determine the gyro flutter stability of the wind tunnel test model under different conditions;

[0082] a) adjusting the wind tunnel test model, adjusting the weight and center of gravity position of the nacelle-wing connection model 7 and the mass block 63 respectively, and completing wind tunnel test conditions such as the nacelle-wing connection stiffness, nacelle weight, center of gravity, etc.;

[0083] b) Carry out wind tunnel blowing test and test data test for each test condition;

[0084] c) Determine the stability of the rotational flutter under different working conditions based on the wind tunnel test results;

[0085] d) Compare with the simulation analysis results of the second step to verify the rotation flutter simulation analysis method of the tiltrotor aircraft rotation flutter wind tunnel test model.

[0086] Step 4: Based on the rotation flutter simulation analysis method verified by the tiltrotor prototype and wind tunnel test, a rotation flutter simulation analysis model for the rotor-nacelle-wing coupling system is established to carry out the rotation flutter stability analysis;

[0087] a) Based on the size of the tiltrotor prototype and the aeroelastic mechanics analysis method, the rotor model, wing model and aerodynamic load analysis model of the tiltrotor are established respectively to form a rotation flutter simulation analysis model of the rotor-nacelle-wing coupling system;

[0088] b) Perform gyroscopic stability analysis on tiltrotor aircraft and solve the gyroscopic flutter stability of the tiltrotor aircraft rotor-nacelle-wing coupling system;

[0089] c) Determine the gyro flutter stability of the rotor-nacelle-wing coupling system of the tiltrotor aircraft. The point where the modal damping ratio is equal to 0 is the critical point. The tiltrotor aircraft being analyzed is in a critical stability state of gyro flutter. The forward flight speed corresponding to the abscissa of the critical point position is the gyro flutter critical speed of the tiltrotor aircraft. When the modal damping ratio is positive, the tiltrotor aircraft being analyzed does not have the risk of gyro flutter; when the modal damping ratio is negative, the tiltrotor aircraft being analyzed has the risk of gyro flutter;

[0090] d) Take the following as an example, Figure 2As the forward flight speed of the analyzed tiltrotor aircraft increases from 220km / h to 500km / h, the symmetrical swing damping of the wing gradually decreases and drops to 0 at 460km / h, that is, the rotation flutter boundary speed is 460km / h. At this speed, the tiltrotor aircraft is in a critical stability state of rotation flutter. When the forward flight speed is lower than 460km / h, the analyzed tiltrotor aircraft will not have rotation flutter instability problems. When the forward flight speed exceeds 460km / h, the analyzed tiltrotor aircraft will have serious rotation flutter instability problems, threatening the model safety.

[0091] Step 5: Using the established tiltrotor aircraft rotation flutter simulation analysis model, the tiltrotor aircraft rotation flutter stability with different nacelle and wing connection stiffness, nacelle weight, and center of gravity is studied, and the rotation flutter simulation analysis model is modified based on the wind tunnel test results;

[0092] a) Based on the tiltrotor aircraft rotation flutter simulation analysis model established in the fourth step, according to the dynamics reduction criterion, determine the actual data of the nacelle and wing connection stiffness, nacelle weight, center of gravity and other data corresponding to the nacelle and wing connection stiffness, nacelle weight, center of gravity in the test;

[0093] b) Study the gyro flutter stability of the tiltrotor aircraft under the actual data of the nacelle and wing connection stiffness, nacelle weight, and center of gravity, analyze the gyro flutter stability, and modify the established tiltrotor aircraft gyro flutter simulation analysis model based on the wind tunnel test results;

[0094] Based on the revised tiltrotor aircraft rotation flutter simulation analysis model, during the model development process, the model is iteratively updated in real time according to actual conditions, and the corresponding rotation flutter stability analysis is carried out to strictly verify that the designed tiltrotor aircraft does not have rotation flutter instability problems within the flight envelope, thereby ensuring the safety of the model.

Claims

1. A nacelle wind tunnel test model for gyroscopic flutter analysis, characterized in that: Designed according to the helicopter nacelle, including: The fuselage model, wing model, nacelle model, rotor model, nacelle-rotor connection model, and nacelle-wing connection model are rigidly mounted on the wind tunnel wall; The wing model is installed on the fuselage model; the nacelle rotor connection model is used to connect the rotor model and the nacelle model; A nacelle rotor connection model is arranged inside the nacelle model, and the nacelle rotor connection model and the nacelle model are arranged to be integrated or rigidly connected; the nacelle wing connection model is connected to the wing model by bolts; Two bearing seats for assembling the rotor shaft are arranged on the nacelle rotor connection model, and a mass block is installed between the two bearing seats.

2. The model according to claim 1, characterized in that The center of gravity of the mass block is designed to be adjustable axially and laterally. The center of gravity heading parameter of the nacelle is changed by moving the mass block axially between the two bearing seats. The lateral center of gravity parameter of the adjustable nacelle is changed by adjusting the lateral center of gravity of the mass block itself.

3. The model according to claim 1, characterized in that The mass block is designed to be a weight-adjustable type or a combination of multiple mass blocks. By changing the weight of the mass block, the weight parameter of the adjustable nacelle can be changed.

4. A simulation verification method for rotary flutter analysis, characterized in that: include: Based on the requirements for adjustable key parameters such as nacelle and wing connection stiffness, nacelle weight, center of gravity, etc., a nacelle wind tunnel test model for rotation flutter analysis as described in any one of claims 1 to 3 is designed; Based on the nacelle wind tunnel test model used for rotation flutter analysis, a rotation flutter simulation analysis model of the wind tunnel test model is established, and the rotation flutter simulation analysis of the nacelle wind tunnel test model used for rotation flutter analysis is carried out; Based on the nacelle wind tunnel test model used for rotation flutter analysis and the wind tunnel test conditions determined by simulation analysis, a wind tunnel blowing test was carried out to determine the rotation flutter stability of the wind tunnel test model under different conditions; Compare the gyro flutter stability and simulation analysis results of the wind tunnel test model under different working conditions to verify the gyro flutter simulation analysis method of the wind tunnel test model of the rotor-nacelle-wing coupling system; Based on the rotational flutter simulation analysis method, a rotational flutter simulation analysis model of the rotor-nacelle-wing coupling system of the tiltrotor prototype is established, and the rotational flutter stability analysis is carried out.

5. The method according to claim 4, characterized in that The method further comprises: The gyro flutter stability of the tiltrotor aircraft with different nacelle and wing connection stiffness, nacelle weight and center of gravity is studied by using the gyro flutter simulation analysis model of the rotor-nacelle-wing coupling system of the tiltrotor prototype.

6. The method according to claim 5, characterized in that Based on the nacelle wind tunnel test model for rotation flutter analysis, a rotation flutter simulation analysis model of the wind tunnel test model is established, and the rotation flutter simulation analysis of the nacelle wind tunnel test model for rotation flutter analysis is carried out, including: Establish a rotation flutter simulation analysis model of the nacelle wind tunnel test model used for rotation flutter analysis, and respectively establish simulation analysis models of the fuselage model, wing model, nacelle model, and rotor model of the wind tunnel test model; The multi-point constraint unit RBE3 is used to simulate the connection between the mass point and the structure, the solid unit is used to simulate the nacelle wing connection model, and the multi-point constraint unit RBE2 is used to simulate the bolt rigid connection. An adjustable nacelle finite element simulation analysis model is established, and the unit properties of the multi-point constraint unit RBE3 simulating the mass block are adjusted. Based on the modal analysis method, the influence of the mass block on the dynamic characteristics of the test model is studied, and the corresponding nacelle weight and center of gravity wind tunnel test conditions are determined. The spring unit is used to simulate the connection stiffness between the nacelle and the wing, and the properties of the spring unit are adjusted. Based on the modal analysis method, the influence of the connection stiffness between the nacelle and the wing on the dynamic characteristics of the test model is studied, and the corresponding wind tunnel test conditions of the connection stiffness between the nacelle and the wing are determined. The wing modal analysis results are input into the rotation flutter simulation analysis model to study the effects of the nacelle-wing connection stiffness, nacelle weight, center of gravity and other parameters on the rotation flutter stability of the test model in preparation for comparison with the wind tunnel test data.

7. The method according to claim 6, characterized in that Based on the gyro flutter simulation analysis method, a gyro flutter simulation analysis model of the rotor-nacelle-wing coupling system of the tiltrotor prototype is established, and the gyro flutter stability analysis is carried out, including: Based on the prototype size and aeroelastic analysis method of the tiltrotor aircraft, the prototype rotor model, wing model, and aerodynamic load analysis model are established to form a simulation analysis model for the rotation flutter of the prototype rotor-nacelle-wing coupling system. The flutter analysis module is used to analyze the gyroscopic stability of the tiltrotor aircraft and solve the gyroscopic flutter stability of the tiltrotor aircraft rotor-nacelle-wing coupling system; Determine the gyroscopic flutter stability of the tiltrotor aircraft rotor-nacelle-wing coupled system.

8. The method according to claim 7, characterized in that The point where the modal damping ratio is equal to 0 is the critical point, and the tiltrotor aircraft is in the critical stable state of rotation flutter. The corresponding forward flight speed is the critical speed of rotation flutter of the tiltrotor aircraft. Under the condition, when the modal damping ratio is positive, the tiltrotor aircraft analyzed has no risk of rotation flutter; when the modal damping ratio is negative, the tiltrotor aircraft analyzed has the risk of rotation flutter.

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