Stator blade adjustment mechanism similarity multifunctional test bench and test method considering aerodynamic load

Abstract

The present invention provides a stator blade adjustment mechanism similarity multi-functional test bench and a test method considering aerodynamic loads. The present invention includes a power drive system, a stator blade adjustment system, a support system, a tooling system, and a test system. Test shaft holes are provided on the outer part of the casing and on the inner ring of the stator. The blade crown and root are respectively inserted into the corresponding shaft holes on the outer part of the casing and the inner ring of the stator. The inner ring of the stator is connected to a spacer block, and the inner ring of the stator can slide in the chute of the spacer block. The power drive system is respectively connected to the outer part of the casing and the input end of the stator blade adjustment system. The constraints of the degrees of freedom of the components of the stator blade adjustment system are the same as those of the corresponding components of the real structure and the dynamic performance is similar. The tooling system is used for loading the aerodynamic loads of the blades and the inner ring of the stator. The test system is used to obtain the dynamic responses of some components in the test bench of the stator blade adjustment mechanism under the condition of applying loads. The present invention can reflect the real dynamic characteristics of the mechanism and has strong expansibility.

Description

Technical Field

[0001] The present invention relates to the technical field of stator vane adjustment mechanisms, and in particular to a stator vane adjustment mechanism similarity multi-functional test bench and a test method considering aerodynamic loads. Background Art

[0002] The stator vane adjustment mechanism is an important part of an aeroengine. Its function is to adjust the angle of the stator vane according to the working state of the engine to delay the compressor stall caused by unstable air flow and expand the stability margin. The stator vane adjustment mechanism is a typical multi-stage link mechanism with a complex structure. It is always affected by friction and wear during the working process. In addition, both the stator vane and the inner ring of the stator are affected by aerodynamic forces. These influencing factors together lead to an increase in the overall mechanism's blocking force and jamming, seriously affecting the safety of the engine. In addition, as a multi-body system, various nonlinear phenomena, such as clearances, friction and wear, forced vibrations, etc., exist in the stator vane adjustment mechanism. The above-mentioned nonlinear factors will all affect the motion accuracy, motion smoothness and force-bearing conditions of the adjustment mechanism. Therefore, it is extremely important to study the influence law of the blocking force of the adjustment mechanism and the influence law of nonlinear factors.

[0003] Publication No. CN112326433A discloses a principle-level adjustment mechanism test bench, which is a 4-level planar adjustment mechanism principle-level test bench, aiming to study the stress and strain conditions of the weak links at all levels of the stator blade adjustment mechanism during movement under the influence of temperature. The specific working principle of the test bench is as follows: On one side of the top of the inner casing, there is a linear motor installation part, and on one side of the top of the linear motor installation part, a linear motor is installed. The end of the linear motor is installed with a rocker, and the rocker is locked and connected to a rotating shaft. The bottom of the rotating shaft is connected to a fixing plate, and the bottom of the rotating shaft is rotatably installed in the shaft groove provided at the top of the fixing plate. The bottom of the rotating shaft is locked and installed with a main transmission rod, and the other end of the main transmission rod is rotatably installed with a connecting rod. The connecting rod is rotatably connected to multiple pairs of transmission rods, and the middle of the transmission rod is rotatably installed at the top of the fixing plate. The bottom of the other end of the transmission rod is ball-jointed with a pull rod, and the other end of the pull rod is ball-jointed with a linkage ring. The linkage ring is rotatably installed with a rocker arm, and at the circular hole at the other end of the rocker arm, a blade is installed. Both ends of the blade are installed on the outer casing and the inner casing respectively, and a support column is fixedly installed at the top of the inner casing. The top of the support column is fixed to the bottom of the fixing plate. Large and small bushings are installed at the upper and lower shaft sections of the blade. A high-frequency heater is provided outside the blade, and a strain gauge is installed at the top of the rocker arm. However, there are the following problems with this patent: First, there is an obvious problem that the research on the influence law of the blocking force and non-linear factors of the stator blade adjustment mechanism is insufficient. Although there is a principle-level stator blade adjustment mechanism test bench, it is first a planar structure. In this case, the movement relationship and degrees of freedom of the components have changed, and it cannot be used to study the influence law of the blocking force, etc.; Second, the external environment simulated by this test bench is a thermal environment, and the pneumatic load environment, which has the greatest influence on the blocking force, is not simulated; Third, the function of this principle-level test bench is single, and it can only be used to study the stress and strain conditions of components in a thermal environment, without considering expanding the function of the test bench. Summary of the Invention

[0004] In view of the above-mentioned technical problems, a stator blade adjustment mechanism similarity multi-functional test bench considering pneumatic load and a testing method are provided. The technical means adopted in the present invention are as follows:

[0005] A stator blade adjustment mechanism similarity multi-functional test bench considering pneumatic loads, comprising a power drive system, a stator blade adjustment system, a support system, a tooling system and a test system. The support system includes a cushion block, an outer casing and a stator inner ring. A number of test shaft holes arranged in a preset specification are provided on the outer casing and the stator inner ring. The blade crown and root are respectively inserted into the corresponding shaft holes of the outer casing and the stator inner ring. The stator inner ring is connected to the cushion block, and the stator inner ring can slide in the chute of the cushion block. The power drive system is respectively connected to the outer casing and the input end of the stator blade adjustment system. The constraints of the degrees of freedom of the components of the stator blade adjustment system are the same as those of the corresponding components of the real structure and the dynamic performance is similar. The tooling system is used for loading the pneumatic loads of the blade and the stator inner ring. The test system is used to obtain the dynamic responses of some components in the stator blade adjustment mechanism test bench under the condition of applying loads.

[0006] Further, the power drive system includes a servo electric cylinder. The servo electric cylinder is respectively connected to the outer casing and the drive arm of the stator blade adjustment mechanism system through the spherical plain bearings at both ends.

[0007] Further, the stator blade adjustment mechanism system includes a third-stage crank, a drive arm, a rotating shaft, a connecting rod, a zero-stage crank, a pull rod, a double-end spherical plain bearing, a radial spherical plain bearing, a rocker arm, a blade, a linkage rod, a slider assembly and a slider support. The output end of the power drive system is connected to the drive arm. The drive arm, the rotating shaft and the third-stage crank are fixedly connected by screws. The third-stage crank is driven to rotate about a fixed axis by the drive arm. The third-stage crank is connected to the zero-stage crank through the connecting rod. The zero-stage crank is connected to the pull rod. The pull rod is connected to the double-end spherical plain bearing. One power transmission chain of the double-end spherical plain bearing is connected to the rocker arm through the radial spherical plain bearing. The rocker arm is connected to the crown of the blade. The other power transmission chain is connected to the slider assembly through the linkage rod.

[0008] Further, it also includes a bottom plate. The cushion block is arranged on the bottom plate. A guide rail is also provided on the bottom plate. The linkage rod is hinged to the slider support on the slider assembly, realizing that the degree of freedom of the linkage rod is 2 and the type of kinematic pair is a cylindrical pair, ensuring that the degree of freedom of the linkage ring of the real stator blade adjustment mechanism is the same.

[0009] Further, the tooling system includes a blade load loading device and a stator inner ring load loading device. The blade load loading device includes a circular clamp, a two-force bar device, a radial force device, and an axial force device. The blade crown and root are respectively inserted into the shaft holes corresponding to the casing and the stator inner ring, and the same gaps as those in the real stator vane adjustment mechanism system are provided at both mating positions. The circular clamp is arranged outside the center of the blade body. The radial force device is used to apply a radial force parallel to the engine axis to the blade body all the time. The axial force device is used to apply an axial force perpendicular to the engine axis and parallel to the axis of the casing hole to the center of the blade body. The axial force device acts on the upper surface of the circular clamp through the two-force bar device;

[0010] The stator inner ring load loading device includes a dynamometer acting on it. An electric push rod is provided at the input end of the dynamometer, and through the telescopic movement of the electric push rod, it acts on the spring dynamometer, thereby driving the stator inner ring to slide in the cushion block chute.

[0011] Further, the test system includes inertial navigation sensors adhered to the drive arm and the blade. The inertial navigation sensor on the drive arm is used to measure the azimuth angle of the rotating shaft relative to the fixed coordinate system of the sensor, as well as the angular velocity and angular acceleration corresponding to the azimuth angle; the inertial navigation sensor on the blade is used to measure the azimuth angle of the blade relative to the fixed coordinate system of the sensor, as well as the angular velocity and angular acceleration corresponding to the azimuth angle.

[0012] A test method for a stator vane adjustment mechanism similarity multifunctional test bench considering aerodynamic loads includes the following steps:

[0013] Step 1: Obtain the dynamic models of the mechanism under ideal conditions, considering clearances, and considering aerodynamic forces;

[0014] Step 2: Given the power source (servo electric cylinder) of the stator vane adjustment mechanism similarity multifunctional test bench, input the same speed as that of the obtained dynamic model and ensure the same running time;

[0015] Step 3: Apply loads to the blade and the stator inner ring through the tooling system;

[0016] Step 4: Through the test system, measure the azimuth angle of the rotating shaft relative to the fixed coordinate system of the sensor, as well as the angular velocity and angular acceleration corresponding to the azimuth angle, and measure the azimuth angle of the blade relative to the fixed coordinate system of the sensor, as well as the angular velocity and angular acceleration corresponding to the azimuth angle;

[0017] Step 5: Calculate the actual angle of the rotating shaft rotating around its axis and the actual angle of the blade rotating around the blade crown axis based on the data measured by the test system;

[0018] Step 6: Compare the actually measured data of the similarity multifunctional test bench with the solution results of the dynamic model to verify the correctness of the model.

[0019] Furthermore, the designed kinetic model is a mechanism kinetic model considering clearances, specifically including a non-linear contact force model, a friction force model, and a wear model.

[0020] The present invention has the following advantages:

[0021] 1. In the structural design of the static blade regulating mechanism similarity test bench of the present invention, the constraints on the degrees of freedom of all components are always the same as those of the corresponding components of the real structure and the kinetic performance is similar, which can reflect the real kinetic characteristics of the mechanism, and then carry out the kinematic and kinetic response tests under ideal conditions.

[0022] 2. When the static blade regulating mechanism is taken as the research object of the present invention, the kinetic response tests under ideal conditions or considering the influences of the clearance type, position, quantity, and clearance value can be carried out. This test bench can consider the non-linear factor of the joint clearance, set different clearance values for different joints by changing the connection and matching dimensions of adjacent components, and then carry out the kinetic response tests considering clearances, so as to obtain the influence rules of the clearance position, quantity, and clearance value under different kinematic pair types on the system response. In addition, the present invention provides a method for kinetic modeling and solution of the regulating mechanism, and the proposed mechanism kinetic model can be verified by using the above kinetic tests.

[0023] 3. The aerodynamic forces of the components (blades, stator inner rings) of the present invention are equivalently simplified according to mechanical knowledge, and the corresponding equivalent loading method is proposed. Then, based on the above kinetic tests, the kinetic tests under the influence of aerodynamic forces can be carried out to obtain the influence rules of the mechanism blocking force, and the model correctness of the proposed mechanism kinetic model considering aerodynamic forces can also be verified.

[0024] 4. As a kind of multi-body system, the present invention can verify and correct the kinetic models of non-linear factors in the mechanism, such as non-linear contact force models, friction force models, wear models, etc., and then correct the kinetic models of the regulating mechanism containing such non-linear factors.

[0025] 5. The present invention uses the inertial navigation system commonly used for pose measurement as the test equipment, which is used for measuring the rotation angle of a rigid body in spatial plane rotation or spatial fixed-axis rotation, proposes a rotation angle calculation algorithm suitable for the above situations, and the algorithm results are stable and reliable, successfully expanding the application occasions of inertial navigation sensors. Description of the Drawings

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the attached drawings required in the description of the embodiments or the prior art. Obviously, the attached drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other attached drawings can also be obtained based on these attached drawings.

[0027] Figure 1 It is a schematic structural diagram of the test bench of the present invention.

[0028] Figure 2 It is a partial enlarged view of the stator vane adjustment system of the present invention.

[0029] Figure 3 It is a schematic diagram of the rocker arm mechanism of the present invention.

[0030] Figure 4 It is a schematic diagram of the loading methods of the axial force and radial force of the blade body center of the present invention. Among them, (a) is the front view of the loading method, and (b) is the top view of the loading method.

[0031] Figure 5 It is a schematic diagram of the inner stator ring loading.

[0032] Figure 6 It is a flow chart of the analysis of the similarity relationship of the structural geometric distortion during the design process of the test bench.

[0033] Figure 7 It is a schematic diagram of the principle of translating force to a point.

[0034] Figure 8 It is a schematic diagram of the structure of the inertial navigation sensor and the coordinate system of the sensor body.

[0035] Figure 9 It is a schematic diagram of the rotation during the process of expanding the functions of the inertial navigation system.

[0036] In the figure: 1. Base plate; 2. Spacer; 3. Outside the casing; 4. Servo electric cylinder; 5. Third-stage crank; 6. Driving arm; 7. Connecting rod; 8. Zero-stage crank; 9. Tie rod; 10. Double-joint bearing; 11. Radial spherical plain bearing; 12. Rocker arm; 13. Blade; 14. Inner stator ring; 15. Linking rod; 16. Rotating shaft; 17. Slide block assembly; 18. Slide block support; 22. Ring fixture; 23. Two-force bar device; 24. Radial force device; 240. Radial force; 25. Axial force device; 250. Axial force. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In response to the need for research on the influencing factors of the blocking force and the influence of non-linear factors mentioned in the background technology, and according to the literature (Attribution analysis of the blocking force and adjustment accuracy of the VSV adjustment mechanism, [J]. Acta Aeronautica et Astronautica Sinica, 2020, 41(12): 423789-423789.) which indicates that most of the blocking force of the adjustment mechanism comes from the influence of aerodynamic force, guided by the verification of the mechanism dynamics model, this embodiment proposes a similar multi-functional test bench and test method for the stator blade adjustment mechanism considering aerodynamic loads, and the technologies involved include three points:

[0039] (1) In the design of the stator blade adjustment mechanism similarity test bench, make full use of the dynamic similarity technology.

[0040] Use physical model (test bench model) tests to effectively simulate the dynamic characteristics and response process of the real adjustment mechanism, and then use the test results of the model to reverse-deduce the dynamic parameters and characteristics of the prototype. The structural design of all components follows the analysis process of the structural geometric distortion similarity relationship, as Figure 6 shown. For example, the blades of an aero-engine have a twisted and irregular structure. When designing the test model, directly designing it with complete similarity has the disadvantages of high cost and greatly extended test cycle. Now, using the geometric distortion model design theory, the twisted structure of the blade is adjusted to a straight plate structure, which greatly reduces the test cost and difficulty and shortens the test cycle.

[0041] (2) In the aspect of loading the aerodynamic force design of components, make full use of the knowledge of force system simplification and equivalence in theoretical mechanics.

[0042] As Figure 7 shown is the schematic diagram of the translation of a force to a point. According to this principle, the force F acting on point A of a rigid body can be translated parallel to any point O, but a couple must be added. The moment of this added couple is equal to the moment of the original force F about the new acting point O. It is known that the directions of the aerodynamic forces are all perpendicular to the surface of the component and are uniformly distributed loads. In the adjustment mechanism, only the outside of the components (blades, stator inner ring) is in an aerodynamic load environment. The direction of the aerodynamic force received by the stator inner ring is parallel to the engine axis direction. According to the theorem of the translation of a force to a point, the uniformly distributed load received by the blade surface can be simplified into a force acting on the center of the blade body plus an added couple.

[0043] (3) In terms of the test method for the dynamic response of the mechanism, the test principle of the sensor (inertial navigation system) is fully utilized and the matrix transformation theory in the multi-body dynamics of the mechanism is used to reverse calculate the rotation angle.

[0044] It is known that the inertial navigation system contains an inertial measurement unit. Through the filtering and fusion algorithm built into the body, it calculates and outputs real-time and accurate carrier attitude, heading information, three-dimensional position and velocity information, as well as information of each inertial device, which can be directly used for vehicle navigation and dynamic attitude measurement. However, if it is used to measure the response of the fixed-axis rotation of a rigid body, etc., it needs to be inversely solved by combining the matrix transformation theory. Figure 8 It is a schematic diagram of the structure of the inertial navigation sensor and the sensor body coordinate system.

[0045] Based on this, the embodiment of the present invention discloses a stator blade adjustment mechanism similarity multi-functional test bench considering aerodynamic loads, including a power drive system, a stator blade adjustment system, a support system, a tooling system, and a test system. Figure 1 It is an assembly drawing of the adjustment mechanism test bench, which is the main component of the present invention, including the power drive system, the stator blade adjustment system, and the support system of the adjustment mechanism similarity test bench. The support system includes a spacer block 2, an outer casing 3, and a stator inner ring 14. A number of shaft holes designed according to the blade positions of the real stator blade adjustment mechanism are provided on the outer casing 3 and the stator inner ring 14. The crown and root of the blade 13 are respectively inserted into the corresponding shaft holes of the outer casing 3 and the stator inner ring 14. The stator inner ring 14 is connected to the spacer block 2, and the stator inner ring 14 can slide in the chute of the spacer block 2. The power drive system is respectively connected to the outer casing 3 and the input end of the stator blade adjustment system. The constraints of the degrees of freedom of the components of the stator blade adjustment system are the same as those of the corresponding components of the real structure and the dynamic performance is similar. The tooling system is used for loading the aerodynamic loads of the blade 13 and the stator inner ring 14. The test system is used to obtain the dynamic response of some components in the stator blade adjustment mechanism test bench under the condition of applying loads.

[0046] Specifically, the power drive system includes a servo electric cylinder 4, and the servo electric cylinder 4 is respectively connected to the outer casing 3 and the driving arm 6 of the stator blade adjustment mechanism system through the joint bearings at both ends.

[0047] In the structural design of the stator blade adjustment mechanism similarity test bench of the present invention, the constraints of the degrees of freedom of all components are always the same as those of the corresponding components of the real structure and the dynamic performance is similar. Specifically, first, a combination of a linkage rod and a slider is used to replace the real linkage ring structure, and the kinematic pairs of both are cylindrical pairs. Second, a double-pass joint bearing is used to replace the joint bearing used in the real mechanism. This structure not only ensures that the three degrees of freedom (ball pair) of this component remain unchanged, but also can avoid the influence of the size of the joint bearing in the real mechanism on the response of the mechanism. As Figure 2 、 Figure 3As shown in the figure, the stator vane adjustment mechanism system includes a third-stage crank 5, a driving arm 6, a rotating shaft 16, a connecting rod 7, a zero-stage crank 8, a pull rod 9, a double-headed spherical plain bearing 10, a radial spherical plain bearing 11, a rocker arm 12, a vane 13, a linkage rod 15, a slider assembly 17, and a slider support 18. The output end of the power driving system is connected to the driving arm 6. The driving arm 6, the rotating shaft 16, and the third-stage crank 5 are fixedly connected by screws. The third-stage crank 5 is driven by the driving arm 6 to rotate about a fixed axis. The third-stage crank 5 is connected to the zero-stage crank 8 through the connecting rod 7. The zero-stage crank 8 is connected to the pull rod 9. The pull rod 9 is connected to the double-headed spherical plain bearing 10. One power transmission chain of the double-headed spherical plain bearing 10 is connected to the rocker arm 12 through the radial spherical plain bearing 11. The rocker arm 12 is connected to the crown of the vane 13. The other power transmission chain is connected to the slider assembly 17 through the linkage rod 15. In this embodiment, the double-headed spherical plain bearing can be selected as a bent rod ball head rod end spherical plain bearing.

[0048] It further includes a bottom plate 1. The cushion block 2 is arranged on the bottom plate 1. A guide rail is also provided on the bottom plate 1. The slider can slide on the guide rail. In this embodiment, the direction of the guide rail is set along the midline of the width direction of the bottom plate. The linkage rod 15 is hinged to the slider support 18 on the slider assembly 17, realizing that the degree of freedom of the linkage rod is 2, and the type of kinematic pair is a cylindrical pair, ensuring that the degree of freedom of the linkage ring of the actual stator vane adjustment mechanism is the same.

[0049] The aerodynamic load simulation of the vane adopts the load equivalent method. The aerodynamic force received by the blade body is a uniformly distributed load perpendicular to the blade surface, and is now simplified into the axial force and radial force received at the center of the blade body. As an alternative implementation, the axial force and radial force loading methods can selectively adopt an axial force and radial force loading device (CN 109932164) with a rotating shaft system of Nanjing University of Aeronautics and Astronautics, such as Figure 4As shown in (a) and (b), the axial force and radial force at the center of the blade body are applied through a circular fixture by an axial force device and a radial force device respectively. The tooling system includes a blade load loading device and a stator inner ring load loading device. The blade load loading device includes a circular ring fixture 22, a two-force rod device 23, a radial force device 24 and an axial force device 25. Among them, the crown and root of the blade 13 are respectively inserted into the corresponding shaft holes of the casing and the stator inner ring 14, and the same clearance as the real stator vane adjustment mechanism system is provided at both mating positions. The circular ring fixture 22 is arranged outside the center of the blade body. The radial force device 24 can provide a radial force 240 parallel to the engine axis, and then acts on the outer surface of the circular ring fixture in a point contact (spherical contact) manner. This force loading method can fully ensure that the direction of the radial force received by the blade body is always parallel to the engine axis. For the axial force loading at the center of the blade body, the axial force device 25 can provide an axial force 250 perpendicular to the engine axis and parallel to the axis of the casing hole, and then directly acts on the two-force rod device 23 and then acts on the upper surface of the circular ring fixture 22 in a point contact (spherical contact) manner. This force loading method can fully ensure that the direction of the axial force received by the blade body is always parallel to the axis of the casing hole.

[0050] The aerodynamic load of the stator inner ring also adopts the load equivalent method and is simplified to an axial force parallel to the engine axis direction. The degree of freedom constraint of the stator inner ring is restricted by the chute of the spacer block 2. In Figure 5 , the crown and root of the blade 13 are respectively inserted into the corresponding shaft holes of the outside of the casing 3 and the stator inner ring 14. The stator inner ring 14 can slide in the chute of the spacer block 2. The right side of the stator inner ring 14 is connected to a spring dynamometer 32, one end of the dynamometer 32 is connected to the stator inner ring 14, and the other end is connected to an electric push rod 31. The right side of the electric push rod 31 is the fixed end. The axial force loading method of the overall stator inner ring 14 is to act on the spring dynamometer 32 through the telescopic movement of the electric push rod, thereby driving the stator inner ring 14 to slide in the chute of the spacer block 2. This force loading method can fully ensure that the direction of the axial force received by the stator inner ring 14 is always parallel to the engine axis 30.

[0051] The present invention proposes an equivalent loading method for the aerodynamic force of components (blades, stator inner rings). After that, based on the above dynamic tests, dynamic tests under the influence of aerodynamic forces can be carried out to obtain the influence law of the mechanism blocking force, and the proposed mechanism dynamics model considering aerodynamic forces can also be verified.

[0052] The test system includes inertial navigation sensors adhered to the driving arm and the blade. The inertial navigation sensor on the driving arm is used to measure the azimuth angle of the rotating shaft relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle. The inertial navigation sensor on the blade is used to measure the azimuth angle of the blade relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle. In this embodiment, the inertial navigation system IMU560 is adopted for the test system of the adjustment mechanism similarity test bench.

[0053] The response test method adopts the method of pasting inertial navigation sensors at two measured positions respectively. The first test position is the rotating shaft 16, and the second test position is the blade 13. The specific scheme is as follows:

[0054] 1) Response test of the rotating shaft 16

[0055] Glue the inertial navigation system IMU560 (the first sensor) face up on the driving arm 2, and keep the X-axis (Roll axis) of the first sensor coincident with the center line direction of the outer surface of the driving arm. The first sensor can measure the azimuth angle of the rotating shaft 16 relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle. The actual angle θ1 of the rotating shaft 16 rotating around the axis needs to be deduced according to the azimuth angle measured by the first sensor.

[0056] For the first sensor, the coordinate system changes during the whole installation and subsequent movement are as follows: fixed coordinate system O-XYZ — initial installation position coordinate system O1-x1y1z1 — final coordinate system O2-x2y2z2. The rotation matrix from the initial installation position coordinate system to the fixed coordinate system is denoted as R x R y R z , and the rotation matrix from the final coordinate system to the initial installation position coordinate system is denoted as where

[0057]

[0058]

[0059] Let the coordinate transformation matrix of the final position i relative to the fixed coordinate system be Then:

[0060]

[0061] Based on the above inferences, it can be obtained that:

[0062]

[0063]

[0064] Finally, the actual rotation angle θ1 of the fixed-axis rotation of the rotating shaft 16 can be reversely solved according to the above formula.

[0065] 2) Blade 13 response test

[0066] Glue the inertial navigation system IMU560 (the second sensor) with its front facing outward to the blade 13, and keep the X-axis (Roll axis) of the second sensor coincident with the direction of the length center line of the outer surface of the blade; the second sensor can measure the azimuth angle of the blade 13 relative to the fixed coordinate system of the sensor, as well as the angular velocity and angular acceleration corresponding to the azimuth angle; the actual angle θ2 of the rotation of the blade 13 around the leaf crown axis needs to be derived according to the azimuth angle measured by the second sensor.

[0067] For the second sensor, the coordinate system change process during the entire installation and subsequent movement is: fixed coordinate system O-XYZ — initial installation position coordinate system O1-x1y1z1 — final coordinate system O2-x2y2z2, and the rotation matrix from the initial installation position coordinate system to the fixed coordinate system is R x R y R z , and the rotation matrix from the final coordinate system to the initial installation position coordinate system is where

[0068]

[0069]

[0070] Here, the approximation principle is adopted, ignoring the thickness of the inertial navigation sensor and the blade thickness, and it is considered that the origin of the inertial navigation sensor is always located on the blade axis. Then, the rotation angle of the inertial navigation sensor around its own x-axis is the blade rotation angle.

[0071] The same as the matrix change of the first sensor, let the rotation coordinate transformation matrix of the final position i relative to the fixed coordinate system be Then:

[0072]

[0073] Based on the above inferences, it can be obtained that:

[0074]

[0075]

[0076] Finally, the actual rotation angle θ2 of the rotation of the blade 13 around the axis can be reversely solved according to the above formula.

[0077] The solution for verifying the dynamic model of the stator blade regulating mechanism in the present invention: Some high-precision simulation methods, such as the analytical method, semi-analytical method, and simulation method, etc., can all be used for the dynamic modeling and solution of the regulating mechanism to obtain the dynamic response of the mechanism under specified inputs. Here, taking the analytical method as an example,

[0078] (1) Establishment of the dynamic model

[0079] For a tree-structured multi-body system with complete and steady constraints, the Lagrange method can be used to establish the dynamic equations of the multi-body system. If the second kind of Lagrange equation with Lagrange multipliers is adopted and the constraint equations are added, a differential-algebraic equation set can be formed as the system dynamic equations.

[0080]

[0081] where M is the mass matrix of the system, including the mass and moment of inertia information of each component. Φ is the kinematic constraint equation of the mechanism, satisfying Φ(Q,t) = 0. Φ Q represents the Jacobian matrix of the constraint equation, F is the generalized force acting on the components within the system, N is the stiffness and damping coupling term of the system, F C is the Baumgarte stabilization term.

[0082] (2) Solution of the dynamic model

[0083] The methods for solving the dynamic equations generally include the augmented method and the condensation method. Among them, the coordinate partitioning method commonly used in the condensation method has good numerical stability.

[0084] In the coordinate partitioning method, first, the generalized coordinates Q of the system containing n components are divided into non-independent coordinates p and independent coordinates q, expressed as

[0085] Q = [Q1 Q2 … Q n T = [p T q T T (2)

[0086] where, the non-independent coordinates p and the independent coordinates q respectively contain i and j coordinates, which are respectively denoted as p = [p1 p2… p i T , q = [q1 q2 … q j T . In the formulas of this article, if the bold characters are not independently explained, they all represent column vectors. According to Equation (2), the equation set of Equation (1) can be transformed into

[0087]

[0088] ​​​​

[0089]

[0090] Simplify and eliminate F in equations (3) and (5). C and We can obtain

[0091]

[0092]

[0093] Substitute equations (6) and (7) into equation (4), and we can obtain the differential equation system (8). Then, the solution methods for differential equation systems commonly used in structural dynamics, such as the Newmark-β method and the Runge-Kutta method, can be used for solution.

[0094]

[0095] Among them,

[0096] (3) Verification of the dynamic model

[0097] The system response obtained by the numerical solution method can be compared with the actual rotation angle obtained through the response test above to verify the correctness of the solution result and the dynamic model.

[0098] The scheme for verifying the dynamic model of nonlinear factors in the present invention is as follows:[[]]

[0099] (1) Verification of the nonlinear contact force model

[0100] The currently commonly used contact force models are all considered to be spring-damping models, such as the L-N model (H.M. Lankarani, P. Nikravesh, A contact force model with hysteresis damping for impact analysis of multibody systems, J. Mech. Des. 112 (1990) 369-76.), the Flores model (P. Flores, M. Machado, M.T. Silva, J.M. Martins, On the continuous contact force models for soft materials in multibody dynamics, Multibody Syst. Dyn. 25 (2010) 357-75.), etc. However, the above non-conformal contact models are all based on the Hertz contact theory and are only applicable to contact situations with large clearances and small loads. The conformal contact model proposed by Li Yuntao (Y. Li, Q. Quan, D. Tang, Modeling and experimental research on a coordinated contact between a shaft and hole, Journal of Harbin Engineering University. 37(2016)1546-52.) is more in line with the actual contact details of the rotating pair. If this conformal contact model is used for the mechanism dynamics modeling considering the clearance, the experimental results can be compared with the theoretical solution results to verify the correctness and applicability of the contact force model.

[0101] (2) Friction force model verification

[0102] The friction force model used in this paper is obtained through friction experiments considering material properties, temperature, etc. Similar to the contact force model, if this contact force model is used for the mechanism dynamics modeling considering the clearance, the experimental results can be compared with the theoretical solution results to verify the correctness and applicability of the friction force model.

[0103] (3) Wear model verification

[0104] The wear model used in this paper is obtained through wear experiments considering material properties, temperature, etc. Similar to the contact force model, if this wear model is used for the mechanism dynamics modeling considering the clearance, the experimental results can be compared with the theoretical solution results to verify the correctness and applicability of the wear model.

[0105] The solution for expanding the functions of the inertial navigation system in the present invention is as follows:

[0106] In addition to being used for three-dimensional space pose measurement, the inertial navigation system can also be used for the response test of spatial plane rotation or spatial fixed-axis rotation. The common feature of the latter two types of rotation is that the axis direction remains parallel or coincident during the rotation process. Figure 9 The schematic diagram of this type of rotation is shown as follows. In Figure 9 , O-XYZ is the system global coordinate system, and the body coordinate system of the component to be measured is O1-X1Y1Z1, and the origin of the body coordinate system is located at the centroid of the component. The component to be measured can rotate freely in the X1O1Y1 plane or always rotate around the spatial axis that coincides with the Z1 axis in the global coordinate system. At this time, the inertial navigation sensor is pasted on the surface of the object to be measured, and a certain axis of the sensor body coordinate system is kept parallel to the Z1 axis of the object coordinate system. If the coordinate system of the inertial navigation sensor coincides with the system global coordinate system O-XYZ when it is not used for testing, then after the first installation of the sensor, the coordinate system change process is represented by the rotation matrix as

[0107]

[0108] where, is the rotation matrix of the coordinate system after installation relative to the global coordinate system, and 0 and 1 represent the two states before and after the sensor installation respectively. R x , R y and R z respectively represent the rotation matrices of the sensor relative to the corresponding axes of its coordinate system, denoted as

[0109]

[0110] The Roll-Pitch-Yaw values in the above rotation matrix are the three azimuth angles measured after the first installation of the sensor. Similarly, if the sensor reaches state 2 after the first installation with the component plane rotation or fixed-axis rotation, then the rotation matrix of the sensor coordinate system relative to the global coordinate system at state 2 is represented as

[0111]

[0112] where, R xi , R yi , R zi are the same as those in formula (9), and also represent the rotation matrices around the x, y, and z axes of the sensor body coordinate system. The difference is that the matrix values are different and still depend on the measured values of the sensor after rotation.

[0113] According to the principle of coordinate system change, the rotation matrix of the final coordinate system can be represented by the rotation matrix of the coordinate system in the intermediate motion process.

[0114]

[0115] where, R θThe rotation matrix for rotation about an axis in the body coordinate system during fixed-axis rotation is the same as Equation (10). Therefore, R can be inversely deduced according to Equations (9), (11), and (12). θ The variable values included in it are the angles of rotation for fixed-axis rotation or planar motion in space.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stator blade adjustment mechanism similarity multi-functional test bench considering aerodynamic loads, characterized in that, It includes a power drive system, a stator blade adjustment system, a support system, a tooling system and a test system, wherein the support system includes a cushion block, a casing exterior and a stator inner ring, the casing exterior and the stator inner ring are provided with a number of test shaft holes arranged in preset specifications, the crown and the root of the blade are respectively inserted into the shaft holes corresponding to the casing exterior and the stator inner ring, the stator inner ring is connected to the cushion block, and the stator inner ring can slide in the slide groove of the cushion block, the power drive system is respectively connected to the casing exterior and the input end of the stator blade adjustment system, the constraints on the degree of freedom of the components of the stator blade adjustment system are the same as those of the corresponding components of the real structure and the dynamic performance is similar, the tooling system is used for aerodynamic load loading of the blades and the stator inner ring, and the test system is used for obtaining the dynamic response of some components in the stator blade adjustment mechanism test bench when the load is applied; The stator blade adjustment mechanism system includes a third-stage crank, a driving arm, a rotating shaft, a connecting rod, a zero-stage crank, a pull rod, a double-headed spherical bearing, a radial spherical bearing, a rocker arm, a blade, a linkage rod, a slider assembly, and a slider support. The output end of the power drive system is connected to the driving arm, and the driving arm, the rotating shaft and the third-stage crank are fixedly connected by screws. The driving arm drives the third-stage crank to rotate on a fixed axis. The third-stage crank is connected to the zero-stage crank through a connecting rod, and the zero-stage crank is connected to the pull rod, and the pull rod is connected to the double-headed spherical bearing. One power transmission branch of the double-headed spherical bearing is connected to the rocker arm through a radial spherical bearing, and the rocker arm is connected to the crown of the blade. The other power transmission branch is connected to the slider assembly through a linkage rod.

2. The stator blade adjustment mechanism similarity multi-functional test bench considering aerodynamic loads according to claim 1, characterized in that The power drive system comprises a servo electric cylinder, and the servo electric cylinder is respectively connected to the outside of the casing and the driving arm of the stator blade adjustment mechanism system through joint bearings at both ends.

3. The stator blade adjustment mechanism similarity multi-functional test bench considering aerodynamic loads according to claim 1, characterized in that, It also includes a base plate, the pad is arranged on the base plate, and the base plate is also provided with a guide rail. The linkage rod is hinged with the slider support on the slider assembly to achieve 2 degrees of freedom of the linkage rod, and the type of the kinematic pair is a cylindrical pair, ensuring the same degree of freedom as the linkage ring of the real stationary blade adjustment mechanism.

4. The stator blade adjustment mechanism similarity multifunctional test bench considering pneumatic load according to claim 1, characterized in that, The tooling system includes a blade load loading device and a stator inner ring load loading device, the blade load loading device includes a circular ring fixture, a two-force rod device, a radial force device and an axial force device, the crown and root of the blade are respectively inserted into the axial holes corresponding to the casing and the stator inner ring, and the two matching positions are provided with the same gap as the real stator blade adjustment mechanism system, the circular ring fixture is arranged outside the center of the blade body, the radial force device is used to load the radial force that is always parallel to the engine axis to the blade body, and the axial force device is used to load the axial force that is perpendicular to the engine axis and parallel to the casing hole axis to the center of the blade body, and the axial force device acts on the upper surface of the circular ring fixture through the two-force rod device; The stator inner ring load loading device includes a dynamometer acting thereon, and an electric push rod is provided at the input end of the dynamometer. The telescopic movement of the electric push rod acts on the spring dynamometer, thereby driving the stator inner ring to slide in the pad slide groove.

5. The stator vane adjustment mechanism similarity multifunctional test bench considering aerodynamic loads according to claim 2, characterized in that The test system includes inertial navigation sensors attached to the driving arm and the blade. The inertial navigation sensor on the driving arm is used to measure the azimuth angle of the rotating shaft relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle. The inertial navigation sensor on the blade is used to measure the azimuth angle of the blade relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle.

6. A testing method for a stator blade adjustment mechanism similarity multifunctional test bench considering aerodynamic loads according to any one of claims 1 to 5, characterized in that, It includes the following steps: Step 1: Obtain the dynamic models of the mechanism under ideal conditions, considering clearances and considering aerodynamic forces. Step 2: Given that the power source of the stator blade adjustment mechanism similarity multi-functional test bench has the same speed input as the obtained dynamic model and ensures the same running time. Step 3: Apply load to the blade and the inner ring of the stator through the tooling system. Step 4: Through the test system, measure the azimuth angle of the rotating shaft relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle, and measure the azimuth angle of the blade relative to the sensor-fixed coordinate system, as well as the angular velocity and angular acceleration corresponding to the azimuth angle. Step 5: Calculate the actual angle of the rotating shaft rotating around its axis and the actual angle of the blade rotating around the blade crown axis based on the data measured by the test system. Step 6: Compare the data actually measured by the similarity multi-functional test bench with the solution results of the dynamic model to verify the correctness of the model.

7. The method according to claim 6, wherein The designed dynamic model is a mechanism dynamic model considering clearances, specifically including a non-linear contact force model, a friction force model, and a wear model.

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