A mechanical decoupling device for aerodynamic drag and inertia force of a dynamic model and a decoupling method thereof

Abstract

The present invention belongs to the technical field of dynamic model aerodynamic force measurement, and specifically relates to a dynamic model aerodynamic resistance and inertial force mechanical decoupling device and a decoupling method thereof, wherein the device comprises a magnetic levitation platform and a mounting plate arranged on the magnetic levitation platform, a first guide rail and a second guide rail are symmetrically arranged on the mounting plate, a model end sliding module and a counterweight end sliding module with the same weight as the model end sliding module are respectively slidably arranged on the first guide rail and the second guide rail, and also comprises a balancing module, a measuring module and a pre-tightening module. Through the cooperation of the above structures, a dynamic model aerodynamic resistance and inertial force mechanical decoupling device with wide adaptability and capable of accurately measuring aerodynamic resistance is comprehensively provided.

Description

Technical Field

[0001] The invention belongs to the technical field of dynamic model aerodynamic force measurement, and in particular relates to a dynamic model aerodynamic resistance and inertial force mechanical decoupling device and a decoupling method thereof. Background Art

[0002] The traditional wind tunnel's "static body and dynamic wind" operation mode determines that the test model must be stationary during aerodynamic measurement, and the flowing wind and the stationary test model produce relative speed to simulate actual movement. Although this aerodynamic measurement method is relatively mature, it cannot meet the test simulation requirements of the dynamic process of aircraft. With the advancement of the times and technology, there is an urgent desire to simulate a physical flight environment that is closer to the real one to meet the requirements of dynamic aerodynamic measurement of aircraft. For this reason, the maglev flight wind tunnel was born.

[0003] Different from traditional wind tunnels, the maglev flight wind tunnel is a large-caliber, long-distance vacuum tube that uses the "body moving and wind static" method to control the physical environment state in the tube. The maglev traction technology drives the linear motion of the test model on the maglev platform, thereby simulating the dynamic process of the aircraft in a near-real environment, providing a more perfect test platform for aircraft, high-speed trains, etc. This test model that moves during the test is called a dynamic model, or "dynamic model" for short.

[0004] There are currently many tests for dynamic models, such as dynamic derivatives, large angles of attack, pitch oscillations, acceleration and deceleration, etc. For example, the Chinese invention patent with application number 202111384332.0 discloses a method for determining the running resistance of a train based on decoupled aerodynamic resistance and mechanical resistance. In this scheme, the mechanical resistance and aerodynamic resistance of the train are obtained through simulation experiments, and then the running resistance of the train is calculated.

[0005] For example, the Chinese invention patent with application number 202211250297.8 discloses a high-speed jet wind tunnel aircraft maneuvering motion decoupling simulation test device. This scheme realizes the decoupling simulation of the deflection and translation motion of the aircraft model under the wind tunnel flow conditions by superimposing the pitch or yaw deflection motion of the aircraft model and the translation motion of the aircraft model, and obtains the decomposed measurement results of the coupled aerodynamic parameters of the aircraft model, which has the beneficial effects of realizing decoupled measurement, improving measurement accuracy, and enhancing applicability.

[0006] However, the test model will produce inertial interference problems during the acceleration and deceleration process, which makes the aerodynamic force measurement of the dynamic model face the challenge of inaccuracy and serious deviation from the true value. The greater the acceleration and deceleration, the more serious the inertial interference problem. Therefore, there is an urgent need for a device that can reduce inertial interference and obtain more accurate aerodynamic resistance. Summary of the invention

[0007] The purpose of the present invention is to provide a mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model, so as to separate the aerodynamic drag and inertial force generated by the dynamic model during acceleration and deceleration, and obtain a "clean" aerodynamic drag.

[0008] In order to solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions: a mechanical decoupling device for aerodynamic resistance and inertial force of a dynamic model, comprising a magnetic levitation platform and a mounting plate arranged on the magnetic levitation platform, wherein a first guide rail and a second guide rail are symmetrically arranged on the mounting plate, a model end sliding module and a counterweight end sliding module with the same weight as the model end sliding module are respectively slidably arranged on the first guide rail and the second guide rail, wherein the model end sliding module comprises a second slider capable of sliding along the second guide rail, a support rod is arranged on the second slider, and a test model is fixed to the second end of the support rod;

[0009] It also includes a balancing module, the balancing module includes a balancing rod support, the first end of the balancing rod support is fixed to the mounting plate, the second end is rotatably provided with a balancing rod, and the two ends of the balancing rod are respectively in contact with the counterweight end sliding module and the first end of the support rod;

[0010] It also includes a measuring module, which includes a sensor support base, a support rod and a sensor. The sensor support base is fixed to the mounting plate, one end of the support rod passes through the sensor support base and can move relative to the sensor support base along the axial direction of the support rod, the other end of the support rod is fixed to the sensor through a sensor mounting chassis, and the sensor is in surface contact with the balance rod.

[0011] As an improvement, at least one pre-tightening module is respectively arranged between the counterweight end sliding module, the model end sliding module and the sensor support base; the pre-tightening module includes an elastic member and a rotating member, and the first side of the rotating member is connected to the first end of the elastic member; the second side of the rotating member and the second end of the elastic member are respectively connected to the first mounting seat on the sensor support base and the counterweight end sliding module, or the second side of the rotating member and the second end of the elastic member are respectively connected to the sensor support base and the model end sliding module.

[0012] As an improvement, the second end of the elastic member is connected to the counterweight end sliding module or the model end sliding module via a fine-tuning screw.

[0013] As an improvement, two mounting posts are symmetrically arranged on the sliding module at the counterweight end and the sliding module at the model end, and at least two threaded holes for installing the fine-tuning screws are arranged on the mounting posts. The two threaded holes on the same mounting post are symmetrical about the horizontal plane where the central axis of the sensor is located. Correspondingly, at least four mounting holes corresponding to the threaded holes are arranged on the sensor support base and the first mounting seat respectively.

[0014] When the preload module is mounted on a corresponding set of the threaded holes and the mounting holes, the central axis of the elastic member is parallel to the central axis of the sensor.

[0015] As an improvement, the mounting plate is further provided with a deflector that cooperates with the sliding module at the counterweight end.

[0016] As an improvement, the mounting plate is provided with a first scale line and a second scale line along its length direction and width direction respectively, the first scale line coincides with the center line of the mounting plate in the length direction, the second scale line is parallel to one of the side walls of the balance pole, and the plane where the second scale line and one of the side walls of the balance pole are located is perpendicular to the plane where the mounting plate is located.

[0017] As an improvement, the counterweight end sliding module includes a first slider and a counterweight block, the counterweight block includes a counterweight body and at least one counterweight plate, the counterweight body is fixedly set on the first slider, the first slider is slidably set on the first guide rail, and the counterweight plate is detachably fixed to the counterweight body.

[0018] The present invention also provides a method for mechanically decoupling aerodynamic drag and inertial force of a dynamic model, which is applied to the above-mentioned device for mechanically decoupling aerodynamic drag and inertial force of a dynamic model, and comprises the following steps:

[0019] S101 weighs a model end sliding module pre-built based on the test model to be tested, and configures a counterweight end sliding module of the same weight based on the weighing result of the model end sliding module;

[0020] S102, selecting a sensor and an elastic member according to preset test conditions, wherein the test conditions include at least one of a test object, a test distance, a test acceleration and deceleration law, and a test number;

[0021] S103 assembling the aerodynamic drag and inertia force mechanical decoupling device of the dynamic model according to preset installation steps;

[0022] When installing the measurement module, it can be installed together with the preload module. The specific installation steps are as follows:

[0023] (1) Prepare a model sample with the same dimensions as the sensor. First, fix the balance bar roughly, then rotate the support bar to push the sensor mounting chassis forward so that the sensor model sample is clamped between the end face of the sensor mounting chassis and the side face of the balance bar.

[0024] (2) Then install an elastic part at the model end. Under the action of the elastic part force, the sensor model sample is clamped. Then repeat the order of "counterweight end-model end" and install the remaining elastic parts in turn. Due to the material of the elastic part, the forces of the elastic parts at the left and right ends are roughly equal. Then adjust the length of the elastic part by rotating the fine-tuning screw to slightly change the force of the elastic part to balance the length error between the elastic parts so that the balance bar is level with the second scale line. At this time, the balance bar is considered to be adjusted correctly.

[0025] (3) Rotate the support rod again to pull the sensor mounting chassis backward. When the gap between the sensor mounting chassis and the balance bar is large enough, install the measuring sensor on the sensor mounting chassis. Rotate the support rod again to push the sensor forward and observe the output of the sensor measuring instrument. When the sensor just contacts the balance bar and the output generated is greater than 0, stop the rotation operation and use this reading as the initial reading of the sensor.

[0026] S104: performing an aerodynamic drag measurement test according to preset test conditions, and deriving the aerodynamic drag of the sliding module at the model end using the following formula;

[0027] , and when , hour, ;

[0028] in, is the acceleration; is the weight of the sliding module at the model end; is the weight of the sliding module at the counterweight end; is the force measured by the sensor; is the actual aerodynamic resistance of the test model to be tested; It is the force arm of the model end sliding module around the rotating fulcrum on the balance rod in the mechanical decoupling device of the aerodynamic resistance and inertial force of the dynamic model; A force arm of the sliding module at the counterweight end around the rotating fulcrum on the balance bar in the mechanical decoupling device of the aerodynamic resistance and inertial force of the dynamic model;

[0029] S105 converts the actual aerodynamic drag data measured in S104 into a drag coefficient using the following formula:

[0030] ; In the formula, is the drag coefficient; is the force measured by the sensor; is the air density; v is the real-time running speed; s is the reference area.

[0031] As an improvement, in step S102, the specific steps of selecting the elastic member include:

[0032] S1021 calculates the total maximum inertia force of the sliding module at the model end and the sliding module at the counterweight end according to the maximum deceleration by using the following formula;

[0033] ;

[0034] in, is the maximum inertia force, is the measured weight of the dynamic model module; is the desired weight of the sliding module at the counterweight end; is the maximum deceleration;

[0035] S1022 uses the calculated maximum inertia force as a reference, multiplying the maximum inertia force by a preset threshold value to obtain a minimum total preload force ;

[0036] S1023 is based on the minimum total preload , select the preload component using the following formula:

[0037] ;

[0038] Where x is the tensile length of the preloaded component; k is the stiffness coefficient of the preloaded component; F0 is the initial tension of the preloaded component; Fpreload = / N, N is the number of preloaded components.

[0039] As an improvement, in step S102, the specific steps of selecting the sensor include:

[0040] S1024, based on the known drag coefficient, calculate the maximum aerodynamic drag using the following formula:

[0041] ;

[0042] In the formula, is the drag coefficient; is the maximum aerodynamic resistance; is the air density; is the maximum operating speed; s is the reference area;

[0043] S1025 determines a maximum force value and a minimum force value; wherein the minimum force value is the maximum aerodynamic resistance, and the maximum force value is the resultant force value of the maximum inertial force, the minimum total preload force, and the maximum aerodynamic resistance;

[0044] S1026 determines the range of the sensor according to the maximum force value and the minimum force value, and selects a sensor with the range.

[0045] The principles and beneficial effects of the present invention are:

[0046] For a dynamic model with acceleration and deceleration conditions, in order to reduce or eliminate the adverse effects of the inertial force generated during the acceleration and deceleration process on the measurement of aerodynamic drag, the present invention proposes a mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model which has wide adaptability and can accurately measure the aerodynamic drag.

[0047] Firstly, the present invention sets a counterweight end sliding module with the same weight as the model end sliding module. During the acceleration and deceleration process, the inertial forces generated by the two act on the balance bar at the same time and can offset each other. Therefore, the aerodynamic resistance generated by the test model can be "cleanly" transmitted to the measurement module, thereby measuring accurate aerodynamic resistance.

[0048] Furthermore, according to different test models, the steps in the method of mechanical decoupling of aerodynamic drag and inertial force of dynamic models can be used to flexibly select corresponding components (such as sensors and elastic parts), so as to adapt to different test models and measure the aerodynamic drag values ​​of different test models. As a result, the device can not only measure the aerodynamic drag of flat plates, but also aircraft, high-speed train models, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without paying creative labor.

[0050] Figure 1 It is a schematic diagram of the overall structure of a dynamic model aerodynamic drag and inertial force mechanical decoupling device according to an exemplary embodiment of the present invention;

[0051] Figure 2 A side view of a mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to an exemplary embodiment of the present invention;

[0052] Figure 3 A top view of a mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to an exemplary embodiment of the present invention;

[0053] Figure 4 It is a basic structural schematic diagram of a dynamic model aerodynamic drag and inertial force mechanical decoupling device according to an exemplary embodiment of the present invention;

[0054] Figure 5 It is a partial structural schematic diagram of a dynamic model aerodynamic drag and inertial force mechanical decoupling device according to an exemplary embodiment of the present invention;

[0055] Figure 6 A partial structural diagram of another part of the mechanical decoupling device for aerodynamic drag and inertia force of a dynamic model according to an exemplary embodiment of the present invention

[0056] Figure 7 is a schematic diagram of the overall structure of a balancing module in an exemplary embodiment of the present invention;

[0057] Figure 8 is a schematic structural diagram of a measurement module in an exemplary embodiment of the present invention;

[0058] Fig. 9 is a structural schematic diagram of a pre-tightening module in an exemplary embodiment of the present invention;

[0059] Fig.10 It is a flow chart of a method for mechanically decoupling aerodynamic drag and inertial force of a dynamic model in an exemplary embodiment of the present invention;

[0060] Fig.11 A comparison diagram of inertia compensation effect curves of a decoupling device in an exemplary embodiment of the present invention;

[0061] Fig.12 It is a comparison diagram of the force measurement curve of the sensor and the simulation curve in the decoupling device in an exemplary embodiment of the present invention.

[0062] Markings in the figure: 1. Magnetic levitation platform; 2. Mounting plate; 3. Fairing; 4. Sensor support base; 5. Cylindrical pin; 6. Support rod; 7. Rotating part; 8. Elastic part; 9. Mounting column; 10. Fine-tuning screw; 11. Counterweight plate; 12. Knurled adjustment screw; 13. Counterweight body; 14. Support rod seat; 15. Support rod; 16 Flange; 17. Test model; 18. Second guide rail; 19. Second slider; 20. Guide rail seat; 21. Balance rod support; 22. Limit nut; 23. Balance rod; 24. Fulcrum seat; 25. Counterweight connecting plate; 26. Support rod connecting plate; 27. Sensor; 28. Sensor mounting chassis. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0064] Herein, suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings by themselves. Therefore, "module", "component" or "unit" can be used mixedly.

[0065] In this document, the terms "upper", "lower", "inner", "outer", "front", "back", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0066] In this document, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] Herein, "and / or" includes any and all combinations of one or more of the listed related items. Herein, "plurality" means two or more, that is, it includes two, three, four, five, etc.

[0068] Embodiment 1

[0069] This embodiment is basically as shown in the attached Figure 1-9 As shown:

[0070] See also Figure 1 and Figure 2 A mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model, comprising a magnetic levitation platform 1 and a mounting plate 2 arranged on the magnetic levitation platform, wherein the mounting plate 2 is symmetrically provided with a first guide rail and a second guide rail 18, wherein a model end sliding module and a counterweight end sliding module having the same weight as the model end sliding module are respectively slidably provided on the first guide rail and the second guide rail 18, wherein the model end sliding module comprises a second slider 19 capable of sliding along the second guide rail, wherein a support rod 15 is provided on the second slider 19, and a test model 17 is fixed to the second end of the support rod 15;

[0071] It also includes a balancing module, which includes a balancing rod support 21, a first end of which is fixed to the mounting plate 2, and a balancing rod 23 is rotatably provided on the second end, and both ends of the balancing rod 23 are in contact with the counterweight end sliding module and the first end of the support rod 15 respectively;

[0072] For example, in some embodiments, the two ends of the balance bar are respectively provided with a groove in the contact parts with the counterweight end sliding module and the model end sliding module. Correspondingly, the counterweight end sliding module and the model end are respectively provided with protrusions that cooperate with the grooves in the contact parts with the balance bar. After the device is assembled, the protrusions are located in the grooves, so that the balance bar is respectively in contact with the counterweight end sliding module and the model end sliding module but not fixed.

[0073] Also includes measurement modules, see Figure 8 The measuring module includes a sensor support base 4, a support rod 6 and a sensor 27. The sensor support base 4 is fixed on the mounting plate 2. One end of the support rod 6 passes through the sensor support base 4 and can move relative to the sensor support base. The other end of the support rod is fixed to the sensor through a sensor mounting chassis. The sensor is in surface contact with the balance rod.

[0074] By respectively setting a model-end sliding module and a counterweight-end sliding module with the same weight as the model-end sliding module at both ends of the balance bar, during the measurement process, the inertial forces generated by the two are offset by the balance bar, thereby separating the inertial force from the aerodynamic drag of the dynamic model, achieving the purpose of decoupling, solving the inertial interference problem encountered in measuring the aerodynamic drag of the dynamic model, and thus measuring accurate results.

[0075] In some embodiments, Figure 2 , at least one pre-tightening module is respectively provided between the sliding module at the counterweight end and the sliding module at the model end and the sensor support base;

[0076] The pre-tightening module includes an elastic member 8 and a rotating member 7, wherein the first side of the rotating member 7 is connected to the first end of the elastic member 8; the second side of the rotating member 7 and the second end of the elastic member 8 are respectively connected to the first mounting seat on the sensor support base 4 and the counterweight end sliding module, or the second side of the rotating member 7 and the second end of the elastic member 8 are respectively connected to the sensor support base 4 and the model end sliding module. By setting the pre-tightening module, part of the inertial force generated during the deceleration process can be offset, and it is ensured that the model end sliding module and the counterweight end sliding module do not lose control.

[0077] In some embodiments, Figure 2The second end of the elastic member is connected to the sliding module at the counterweight end or the sliding module at the model end through a fine-tuning screw 10. The fine-tuning screw can achieve fine-tuning of the length of the elastic member, thereby ensuring that the preload force of each elastic member is the same, thereby ensuring that the balance bar can be straightened and making the entire device more stable.

[0078] In some embodiments, Figure 6 The counterweight end sliding module and the model end sliding module are symmetrically provided with mounting columns 9, and the mounting columns 9 are provided with at least two threaded holes for installing the fine-tuning screws. The two threaded holes on the same mounting column 9 are symmetrical about the horizontal plane where the central axis of the sensor is located. Correspondingly, the sensor support base and the first mounting seat are respectively provided with at least four mounting holes corresponding to the threaded holes, and the mounting holes are used to install the rotating member;

[0079] When the preload module is installed on a corresponding set of the threaded holes and the mounting holes, the central axis of the elastic member is parallel to the central axis of the sensor, and the multiple elastic members work together to enable the sensor to always maintain balance.

[0080] In some embodiments, Figure 4 The mounting plate 2 is also provided with a deflector 3 that cooperates with the counterweight end sliding module. Specifically, the deflector covers the surroundings of the terminal sliding module, which can prevent the counterweight end sliding module from generating wind resistance during the sliding process to affect the measurement results.

[0081] In some embodiments, see Figure 3 and Figure 4 The mounting plate is provided with a first scale line and a second scale line along its length direction and width direction, respectively. The first scale line coincides with the center line of the mounting plate in the length direction, the second scale line is parallel to one of the side walls of the balance pole, and the plane where the second scale line and one of the side walls of the balance pole are located is perpendicular to the plane where the mounting plate is located. The two scale lines can assist in positioning during the installation of the balance pole. When the balance pole is installed in place, the first scale line is perpendicular to the balance pole, and the second scale line is parallel to the balance pole.

[0082] In some embodiments, Figure 6 The counterweight end sliding module includes a first slider and a counterweight block, the counterweight block includes a counterweight body 13 and at least one counterweight plate 11, the counterweight body 13 is fixedly arranged on the first slider, the first slider is slidably arranged on the first guide rail, and the counterweight plate is detachably fixed on the counterweight body. After the counterweight body is determined, the total weight of the counterweight block can be adjusted by adjusting the counterweight plate thereon, so as to better adapt to the weight of the model end sliding module.

[0083] In some embodiments, Figure 5 The model end sliding module is also provided with a second mounting seat, and the second end of the support rod 15 passes through the second mounting seat and is connected to the test model. Herein, the second mounting seat may also be referred to as the support rod seat 14.

[0084] In some embodiments, Figure 6 The counterweight end sliding module is provided with a counterweight connecting plate 25, and the counterweight block is fixed to the counterweight end sliding module through the counterweight connecting plate 25; the model end sliding module is provided with a support rod connecting plate, and the model end sliding module and the second mounting seat are respectively fixed on the support rod connecting plate.

[0085] For example:

[0086] In some embodiments, the test model can be a flat plate with equal length, width and uniform thickness. Accordingly, the model end sliding module includes a flat plate, a flat plate flange, a support rod, a support rod seat, a support rod seat connecting plate (also referred to as a support rod connecting plate), a slider, a fulcrum seat, and a spring-buckle pull column (also referred to as a mounting column in this embodiment). The support rod is a carbon tube with equal wall thickness. The flat plate flange connects the second end of the support rod with the flat plate. The support rod seat is used to fix the support rod. The support rod seat connecting plate connects the support rod seat and the slider. The slider is slidably connected to the second guide rail and supports all parts of the model end sliding module to ensure that the model end sliding module has only a degree of freedom along the direction of movement. The fulcrum seat is connected to an end face of the support rod seat at the first end of the support rod, and the spring-buckle pull column is fixed to the two side surfaces of the support rod seat at the first end of the support rod.

[0087] See also Figure 6 The sliding module at the counterweight end includes: a counterweight body 13, a counterweight plate 11, a support rod seat 14, a counterweight connecting plate 25, a slider, a fulcrum seat, a spring buckle pull column, and a knurled adjustment screw 12. The slider, spring buckle pull column, support rod seat and fulcrum seat are all the same as the structures in the sliding module at the model end. The counterweight body is fixed on the upper surface of the counterweight connecting plate, the knurled adjustment screw is connected to the screw hole on the counterweight body, and the counterweight plate is limited to the counterweight body by the knurled adjustment screw, and the number can be increased or decreased by the knurled adjustment screw.

[0088] See also Figure 7The balancing module includes a balancing rod 23, a balancing rod support 21, a tapered roller bearing, and a limit nut 22. The balancing rod support is fixedly connected to a large base plate (also referred to as a mounting plate in this embodiment), and has a step structure and an external thread structure. The tapered roller bearing is interference-connected in a non-through slot hole on the lower surface of the balancing rod. The balancing rod is limited in the negative direction of height by the contact between the end face of the tapered roller bearing and the step surface of the balancing rod support. At the same time, a part of it passes through the external thread structure of the balancing rod support and can rotate around the balancing rod support. The limit nut cooperates with the external thread of the balancing rod support to limit the height of the balancing rod in the positive direction.

[0089] The measuring module includes a single-component force sensor (that is, the sensor in this embodiment), a sensor support rod, a sensor mounting chassis, a sensor support base, and a cylindrical pin. The sensor support base is fixedly connected to the large base plate and has plate-like structures on both sides. The sensor support rod is connected by threads and passes through the sensor support base. A pin hole is opened at the tail. The forward and backward movement of the sensor support rod is achieved by the cylindrical pin. The sensor mounting chassis is a circular disk with a certain thickness and a countersunk hole in the middle of the disk. The single-component force sensor is a force sensor with a flange connection structure on both sides. One side is connected to the sensor mounting chassis by screws, and the other side is directly in surface contact with the side of the balance bar.

[0090] The preload module includes an elastic part (preferably a tension spring), a fine-tuning screw, and a rotating part (preferably a universal rotating ring). The universal rotating ring is fixedly connected to the plate-like structure of the sensor support base in the measuring module by threads and can rotate freely 360°. The tension spring is a parallel hook-type tension spring, which is hung on the universal rotating ring and the fine-tuning screw at the front and back respectively. The fine-tuning screw is connected to the spring buckle pull column in the model end sliding module and the counterweight end sliding module by threads, and is used to fine-tune the length of the tension spring to ensure that the initial position of the balance bar is correct.

[0091] Working principle:

[0092] The balance bar in the present invention is similar to a lever, and the model end sliding module and the counterweight end sliding module are symmetrically arranged on both sides thereof. During the acceleration and deceleration process, the model end sliding module and the counterweight end sliding module will generate inertial force by their own weight, acting on the positions in contact with the two ends of the balance bar, and symmetrically about the fulcrum of the lever. Since the model end sliding module and the counterweight end sliding module have equal weight, equal center of mass height, and only one degree of freedom in one direction of movement, the inertial force is not only equal, but can also act on the balance bar at the same time. Since the force arms are equal, but the torque directions are opposite, the inertial force is offset. During the acceleration and deceleration process, the aerodynamic resistance of the flat plate model generated by the speed is "cleanly" transmitted to the measurement module, thereby measuring the aerodynamic resistance of the flat plate model.

[0093] Embodiment 2

[0094] The present invention also provides a method for mechanically decoupling aerodynamic drag and inertia force of a dynamic model, which is applied to the mechanical decoupling device for aerodynamic drag and inertia force of a dynamic model described in the first embodiment, see Fig.10 , including the following steps:

[0095] S101 weighs a model end sliding module pre-built based on the test model to be tested, and configures a counterweight end sliding module of the same weight based on the weighing result of the model end sliding module;

[0096] S102, selecting a sensor and an elastic member according to preset test conditions, wherein the test conditions include at least one of a test object, a test distance, a test acceleration and deceleration law, and a test number;

[0097] S103 assembling the aerodynamic drag and inertia force mechanical decoupling device of the dynamic model according to preset installation steps;

[0098] S104: performing an aerodynamic drag measurement test according to preset test conditions, and deriving the aerodynamic drag of the sliding module at the model end using the following formula;

[0099] , and when , hour, ;

[0100] That is, ,

[0101]

[0102] when ,Right now hour

[0103] ,Right now

[0104] in, is the acceleration; is the inertia force of the sliding module at the model end; is the weight of the sliding module at the model end; is the inertia force of the sliding module at the counterweight end; is the weight of the sliding module at the counterweight end; is the force measured by the sensor; is the actual aerodynamic resistance of the test model to be tested; It is the force arm of the model end sliding module around the rotating fulcrum on the balance rod in the mechanical decoupling device of the aerodynamic resistance and inertial force of the dynamic model; A force arm of the sliding module at the counterweight end around the rotating fulcrum on the balance bar in the mechanical decoupling device of the aerodynamic resistance and inertial force of the dynamic model;

[0105] S105 converts the actual aerodynamic drag data measured in S104 into a drag coefficient using the following formula:

[0106] ; In the formula, is the drag coefficient; is the force measured by the sensor; is the air density; v is the real-time running speed; s is the reference area.

[0107] The present invention sets a counterweight end sliding module with the same weight as the model end sliding module. During the acceleration and deceleration process, the inertial forces generated by the two simultaneously act on the balance bar and can offset each other. Therefore, the aerodynamic resistance generated by the test model can be "cleanly" transmitted to the measurement module, thereby accurately measuring the aerodynamic resistance.

[0108] Furthermore, for different test models, the steps in the method of mechanical decoupling of aerodynamic drag and inertial force of the dynamic model can be used to flexibly select corresponding components, so that the aerodynamic drag values ​​of different test models can be measured. At the same time, the aerodynamic drag values ​​are dimensionless, so that the aerodynamic drag values ​​of different test models can be quickly obtained through this method.

[0109] In some embodiments, in step S102, the specific steps of selecting the elastic member include:

[0110] S1021 calculates the total maximum inertia force of the sliding module at the model end and the sliding module at the counterweight end according to the maximum deceleration by using the following formula;

[0111] ;

[0112] in, is the maximum inertia force, is the measured weight of the dynamic model module; is the desired weight of the sliding module at the counterweight end; is the maximum deceleration;

[0113] S1022 uses the calculated maximum inertia force as a reference, multiplying the maximum inertia force by a preset threshold value to obtain a minimum total preload force ;

[0114] S1023 is based on the minimum total preload , select the preload component using the following formula:

[0115] ;

[0116] Where x is the tensile length of the preloaded component; k is the stiffness coefficient of the preloaded component; F0 is the initial tension of the preloaded component; Fpreload = / N, N is the number of preloaded components.

[0117] Accordingly, the specific steps for selecting the sensor include:

[0118] S1024, based on the known drag coefficient, calculate the maximum aerodynamic drag using the following formula:

[0119] ;

[0120] In the formula, is the drag coefficient; is the maximum aerodynamic resistance; is the air density; is the maximum operating speed; s is the reference area;

[0121] S1025 determines a maximum force value and a minimum force value; wherein the minimum force value is the maximum aerodynamic resistance, and the maximum force value is the resultant force value of the maximum inertial force, the minimum total preload force, and the maximum aerodynamic resistance;

[0122] S1026 determines the range of the sensor according to the maximum force value and the minimum force value, and selects a sensor with the range.

[0123] In order to further verify the decoupling effect of the above device and method, the following experiment was carried out. The specific experimental steps are as follows:

[0124] S1, clarify the test requirements, determine the test model and size, and reasonably design the connecting parts between the test model and the device; S2, weigh the parts of the sliding module at the model end; S3, select the sensor and tension spring according to the test conditions, and design the sensor installation chassis according to the selected sensor; S4, design the counterweight body, weigh and level the sliding module at the counterweight end; S5, confirm test condition 1 (this condition does not consider the model installation of inertial decoupling); S6, conduct aerodynamic drag measurement test without a counterweight sliding module; S7, confirm test condition 2 (this condition considers the model installation of inertial decoupling); S8, conduct aerodynamic drag measurement test with a counterweight sliding module; S9, data processing and comparative analysis of aerodynamic drag measurement tests with and without a counterweight.

[0125] Among them, the test requirements in S1 are provided as input conditions by the test demander, including but not limited to the test object, test distance, test acceleration and deceleration rules, number of tests, etc.

[0126] For example:

[0127] The test object is a flat plate model, the effective test distance is 400m, the maximum acceleration is 10g, the maximum deceleration is 20g, the maximum speed is no more than 170m / s, and the number of tests is 1, where "g" represents the acceleration of gravity in m / s 2 .

[0128] It should be noted that the test model in S1 includes but is not limited to a flat plate model, a scaled model of an aircraft, and a scaled model of a high-speed train. In this embodiment, the test model is a flat plate model, and the connecting part between the flat plate model and the support rod is a flat plate flange. The test model is designed to be lightweight.

[0129] Correspondingly, the components of the sliding module at the model end in S2 include: flat plate, flat plate flange, support rod, support rod seat, support rod seat connecting plate, slider, fulcrum seat, spring buckle pull column, and all connecting fasteners. The weight unit must be accurate to grams. Through measurement, the total mass of the sliding module components at the model end in this article is 5945g (grams).

[0130] The following steps are used to select the sensor and tension spring in S3:

[0131] S31, according to the maximum deceleration, the total maximum inertia force of the sliding module at the model end and the sliding module at the counterweight end is calculated by the following formula;

[0132]

[0133] In the formula, is the maximum inertia force, in N, is the weight measured in S2, in kg; is the desired weight of the sliding module at the counterweight end, in kg; The maximum deceleration required for the test in S1, in m / s 2 ; When the weight of the sliding module at the model end and the sliding module at the counterweight end are equal, both are 5945g (grams), the maximum inertia force during deceleration is calculated 2330N;

[0134] S32, based on the calculated maximum inertia force as the basis, the minimum total preload force is calculated according to at least 1.2 times the maximum inertia force , ensure a certain preload margin, i.e. 2797N;

[0135] S33, by minimum total preload , select the tension spring. The principle of selection should not only meet the S32 preload margin requirements, but also consider the difficulty of spring stretching. A too large stiffness coefficient is not easy to install. This device can install 16 tension springs in total, so the preload of each spring is It is 174.8N.

[0136] The following formula can be used to select the tension spring:

[0137]

[0138] Wherein, x is the spring stretching length, unit is mm; k is the stretching spring stiffness coefficient, unit is N / mm; F0 is the initial tension of the stretching spring, which is a known quantity, unit is N; this paper selects a stretching spring with an initial tension of 68.65N and a stiffness coefficient of 6.19N / mm. To meet the preload requirement of a single spring, the spring stretching length must be at least 17.1mm. It is advisable to take the stretching length as 18mm, then the actual preload of a single spring is 180N, and the total preload is 2881N, which meets the requirements of S32.

[0139] S34, calculate the maximum aerodynamic drag of the test model by CFD simulation, or if the drag coefficient is known, the maximum aerodynamic drag can also be calculated by the following formula:

[0140]

[0141] In the formula, is the drag coefficient; is the maximum aerodynamic resistance, in N; is the air density, unit; is the maximum operating speed, in m / s; s is the reference area, in m 2 ;

[0142] S35, when inertial decoupling is not considered, the preload module only exists on the sliding module side of the model end, with a total of 8 tension springs. The force sensor will measure the combined force of the spring preload, the inertial force of acceleration and deceleration, and the aerodynamic resistance; when inertial decoupling is considered, the preload module exists on both sides of the sliding module at the counterweight end and the sliding module at the model end, with a total of 16 springs, and the force sensor will only measure the aerodynamic resistance. The sensor range can be obtained through the two states. Not considering inertial decoupling means that the sliding module at the counterweight end is not installed, and vice versa. It is preferred to use a force sensor with a double-sided flange connection, with an accuracy better than 0.1%FS and an accuracy better than 0.3%FS. In this test, the NS-WL7 series force sensor is selected, with an accuracy of ±0.05%FS and an accuracy of ±0.1%FS.

[0143] Preferably, the counterweight body in S4 needs to be designed according to the weight of the sliding module at the model end. After the weight of the counterweight body is taken into account in the sliding module at the counterweight end, the total mass of the sliding module at the counterweight end should not differ from the mass of the sliding module at the model end by more than 200g (grams). Then, the weight is balanced by using different numbers of counterweight plates, each weighing 10g (grams). Finally, the weight of the sliding module at the model end should not differ from the weight of the sliding module at the counterweight end by more than 10g (grams). At the same time, it is necessary to ensure that the designed counterweight body can make the center of mass height difference between the sliding module at the end and the sliding module at the counterweight end in the direction perpendicular to the bottom surface not exceed 0.5mm.

[0144] The model installation without inertial decoupling in S5 adopts the following steps:

[0145] S51 installation basic module, including: magnetic levitation platform, large base plate, deflector, linear guide rail, linear guide rail seat. The magnetic levitation platform is towed and guided by the magnetic levitation drive system, which is the input condition of the design. The large base plate is fixedly connected to the magnetic levitation platform to support all parts. The linear guide rail seat is fixedly connected to the large base plate. The linear guide rail is fixedly connected to the linear guide rail seat. The deflector is fixedly connected to the large base plate to avoid wind resistance generated by the sliding module at the counterweight end.

[0146] S52 installs the model end sliding module, including: a flat plate, a flat plate flange, a support rod, a support rod seat, a support rod seat connecting plate, a slider, a fulcrum seat, and a spring buckle pull column. The flat plate is a test model with equal length, width and uniform thickness. The support rod is a carbon tube with equal wall thickness. The flat plate flange connects the support rod and the flat plate. The support rod seat is used to fix the support rod. The support rod seat connecting plate connects the support rod seat and the slider. The slider is connected to the linear guide rail of the basic module and supports all parts of the model end sliding module to ensure that the model end sliding module has only a degree of freedom along the direction of movement. The fulcrum seat is connected to one end face of the support rod seat at the front end of the support rod, and the spring buckle pull column is fixed to the two side faces of the support rod seat at the front end of the support rod.

[0147] S53 installs a balancing module, including: a balancing pole, a balancing pole support, a tapered roller bearing and a limit nut. The balancing pole support is fixedly connected to the large base plate and has a step structure and an external thread structure. The tapered roller bearing is interference-connected in the non-through slot hole on the lower surface of the balancing pole. The balancing pole is limited in the negative direction of height by the contact between the end face of the tapered roller bearing and the step surface of the balancing pole support. At the same time, a part of the balancing pole passes through the external thread structure of the balancing pole support and can rotate around the balancing pole support. The limit nut cooperates with the external thread of the balancing pole support to limit the height of the balancing pole in the positive direction.

[0148] S54 installation measurement module, including: a single-component force sensor, a sensor support rod, a sensor mounting chassis, a sensor support base, and a cylindrical pin. The sensor support base is fixedly connected to the large base plate and has plate-like structures on both sides. The sensor support rod is connected by threads and passes through the sensor support base. A pin hole is opened at the tail. The forward and backward movement of the sensor support rod is achieved by the cylindrical pin. The sensor mounting chassis is a disk with a certain thickness and a countersunk hole in the middle of the disk. The single-component force sensor is a force sensor with a flange connection structure on both sides. One side is connected to the sensor mounting chassis by screws, and the other side is directly in surface contact with the side of the balance bar. Since the aerodynamic resistance measurement test without considering inertial decoupling is performed first, the sensor with a range without considering inertial decoupling in S35 should be used.

[0149] The preload module on the S55 model side is installed, including: a tension spring, a fine-tuning screw, and a universal rotating ring. The universal rotating ring is fixedly connected to the plate-like structure of the sensor support base in the measuring module by threads and can rotate freely 360°. The tension spring is a parallel hook-type tension spring, which is hung on the universal rotating ring and the fine-tuning screw at the front and back respectively. The fine-tuning screw is connected to the spring buckle pull column in the sliding module at the model end and the sliding module at the counterweight end by threads, and is used to fine-tune the length of the tension spring to ensure that the initial position of the balance bar is straight.

[0150] The initial position adjustment of the S56 device and the sensor reading. When the side of the balance bar is coplanar with the scale line on the large base plate, it can be considered that the balance bar has been adjusted. At this time, the sensor is read to obtain an initial reading of the preload force.

[0151] In some embodiments, when the measuring module is installed, it can be installed together with the preload module. The specific installation steps are as follows:

[0152] (1) Prepare a model sample with the same dimensions as the sensor. First, fix the balance bar roughly, then rotate the support bar to push the sensor mounting chassis forward so that the sensor model sample is clamped between the end face of the sensor mounting chassis and the side face of the balance bar.

[0153] (2) Then install an elastic part at the model end. Under the action of the elastic part force, the sensor model sample is clamped. Then repeat the order of "counterweight end-model end" and install the remaining elastic parts in turn. Due to the material of the elastic part, the forces of the elastic parts at the left and right ends are roughly equal. Then adjust the length of the elastic part by rotating the fine-tuning screw to slightly change the force of the elastic part to balance the length error between the elastic parts so that the balance bar is level with the second scale line. At this time, the balance bar is considered to be adjusted correctly.

[0154] (3) Rotate the support rod again to pull the sensor mounting chassis backward. When the gap between the sensor mounting chassis and the balance bar is large enough, install the measuring sensor on the sensor mounting chassis. Rotate the support rod again to push the sensor forward and observe the output of the sensor measuring instrument. When the sensor just contacts the balance bar and the output generated is greater than 0, stop the rotation operation and use this reading as the initial reading of the sensor.

[0155] Accordingly, the unweighted aerodynamic drag measurement test in S6 should be carried out in a straight-line acceleration and deceleration test according to the conditions given in the test requirements. The conditions given in this article are acceleration 10g, deceleration 20g, maximum speed not exceeding 170m / s, and effective usable distance 400m. At the same time, the test data should be collected, where "g" here represents the acceleration due to gravity, and the unit is m / s 2 .

[0156] The model installation considering inertial decoupling in S7 adopts the following steps:

[0157] S71 uninstalls the preload module on the model side (since the sliding module on the counterweight end of the sensor installation needs to be replaced, the preload module on the model side must be uninstalled first).

[0158] S72 installs the sliding module at the counterweight end, including: a counterweight body, a counterweight plate, a support rod seat, a counterweight connecting plate, a slider, a fulcrum seat, a spring buckle pull column, and a knurled adjustment screw. The slider, the spring buckle pull column, the support rod seat, and the fulcrum seat are the same as those in the sliding module at the model end. The counterweight body is fixed on the upper surface of the counterweight connecting plate. The knurled adjustment screw is connected to the screw hole on the counterweight body. The counterweight plate is restricted on the counterweight body by the knurled adjustment screw, and the number can be increased or decreased by the knurled adjustment screw.

[0159] S73 installs double-sided preload modules. The preload modules should be installed in a cyclic manner in the order of counterweight side first and then model side, one spring at a time, until all tension springs are installed. After the preload modules are installed, the balance bar should be basically in a balanced and static state.

[0160] The measurement module of S74 is installed in the same way as S54, except that the sensor with the measuring range under the condition of inertial decoupling is replaced, and the sensor support rod thread is advanced or retreated so that one end face of the sensor contacts the balance rod surface. When there is a tiny reading, the operation can be stopped.

[0161] The initial position adjustment of the S75 device and the sensor reading. When the side of the balance bar is coplanar with the scale line on the large base plate, it can be considered that the balance bar has been adjusted. At this time, the sensor is read as the initial reading. The initial reading at this time is close to 0 and does not contain preload.

[0162] Among them, S8 has a counterweight aerodynamic drag measurement test, which is the same as S6, except that a counterweight end sliding module is installed and a sensor that considers the range under inertial decoupling conditions is replaced. Since the initial reading of the sensor is close to 0, the collected data does not need to be subtracted from the initial reading.

[0163] The data collected in S9 for the aerodynamic drag measurement test without counterweight should be deducted from the initial force read in S56 to obtain the resultant force of the measured inertial force and the aerodynamic drag, while the data collected in the aerodynamic drag measurement test with counterweight does not need to be deducted.

[0164] Finally, the results of the two cases are compared. For example, in the design stage, the force measurement results with and without counterweight (that is, before and after inertial decoupling) can be simulated by kinematic simulation software. The motion law is consistent with the test requirements in S1. In specific operations, a constant backward resistance value of 3440N can be artificially applied to the front end of the tablet. Fig.11 The comparison curves of the results measured with and without counterweights are shown, which prove the effect of inertial decoupling. Specifically, when the counterweight end sliding module is not installed, that is, when inertial decoupling is not performed (see Fig.11 The dotted part in the figure), its maximum acceleration is 12g (g represents the acceleration due to gravity, the unit is m / s 2 ), the simulated force of 5421N is approximately equal to the sum of the preload force of 1440N, the inertia force of the sliding module at the model end of 706N and the constant resistance value of 3440, which is 5586N; after inertial decoupling, Fig.11 The solid line part in the figure has an average value of approximately 3368N.

[0165] In order to clearly show the relationship between the resistance value after inertial decoupling of the device and the actual resistance value, the simulated test data of the aerodynamic resistance with counterweight is plotted separately to obtain Fig.12 The curve shown in Figure 2 shows that the dashed line represents the simulation data obtained under the same conditions, and the solid line represents the actual data after decoupling (i.e. Fig.11 The local enlarged view of the solid line in the figure), the average value of the dotted line data in this figure is about 3368N, and the aerodynamic drag result after decoupling can be further calculated to have an error of 2% compared with the constant drag value applied.

[0166] It can be seen that the aerodynamic drag result after decoupling by the device is very close to the actual drag value. Therefore, the dynamic model aerodynamic drag and inertial force mechanical decoupling device of the present invention can truly and effectively eliminate the adverse effects of inertial force on aerodynamic drag measurement during acceleration and deceleration, which also confirms the reliability of the device.

[0167] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0168] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model, characterized in that: The invention comprises a magnetic levitation platform and a mounting plate arranged on the magnetic levitation platform, wherein a first guide rail and a second guide rail are symmetrically arranged on the mounting plate, a model end sliding module and a counterweight end sliding module with the same weight as the model end sliding module are slidably arranged on the first guide rail and the second guide rail respectively, and the model end sliding module comprises a second sliding block capable of sliding along the second guide rail, a support rod is arranged on the second sliding block, and a test model is fixed on the second end of the support rod; It also includes a balancing module, the balancing module includes a balancing rod support, the first end of the balancing rod support is fixed to the mounting plate, the second end is rotatably provided with a balancing rod, and the two ends of the balancing rod are respectively in contact with the counterweight end sliding module and the first end of the support rod; It also includes a measuring module, which includes a sensor support base, a support rod and a sensor. The sensor support base is fixed on the mounting plate, one end of the support rod passes through the sensor support base and can move relative to the sensor support base, the other end of the support rod is fixed to the sensor through a sensor mounting chassis, and the sensor is in surface contact with the balance rod.

2. The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to claim 1, characterized in that: At least one pre-tightening module is respectively arranged between the counterweight end sliding module, the model end sliding module and the sensor support base; The pre-tightening module includes an elastic member and a rotating member, wherein the first side of the rotating member is connected to the first end of the elastic member; the second side of the rotating member and the second end of the elastic member are respectively connected to the first mounting seat on the sensor support base and the counterweight end sliding module, or the second side of the rotating member and the second end of the elastic member are respectively connected to the sensor support base and the model end sliding module.

3. The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to claim 2, characterized in that: The second end of the elastic member is connected to the counterweight end sliding module or the model end sliding module through a fine-tuning screw.

4. The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to claim 3, characterized in that: The counterweight end sliding module and the model end sliding module are symmetrically provided with two mounting columns, respectively, and the mounting columns are provided with at least two threaded holes for installing the fine-tuning screws, and the two threaded holes on the same mounting column are symmetrical about the horizontal plane where the central axis of the sensor is located, and correspondingly, the sensor support base and the first mounting seat are respectively provided with at least four mounting holes corresponding to the threaded holes; When the preload module is mounted on a corresponding set of the threaded holes and the mounting holes, the central axis of the elastic member is parallel to the central axis of the sensor.

5. The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to claim 1, characterized in that: The mounting plate is also provided with a deflector that cooperates with the sliding module at the counterweight end.

6. The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to claim 1, characterized in that: The mounting plate is provided with a first scale line and a second scale line along its length direction and width direction respectively, the first scale line coincides with the center line of the mounting plate in the length direction, the second scale line is parallel to one of the side walls of the balance pole, and the plane where the second scale line and one of the side walls of the balance pole are located is perpendicular to the plane where the mounting plate is located.

7. The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model according to claim 1, characterized in that: The counterweight end sliding module includes a first slider and a counterweight block, the counterweight block includes a counterweight body and at least one counterweight plate, the counterweight body is fixedly arranged on the first slider, the first slider is slidably arranged on the first guide rail, and the counterweight plate is detachably fixed to the counterweight body.

8. A method for mechanically decoupling aerodynamic drag and inertial force of a dynamic model, characterized in that: The mechanical decoupling device for aerodynamic drag and inertial force of a dynamic model as claimed in any one of claims 1 to 7 comprises the following steps: S101 weighs a model end sliding module pre-built based on the test model to be tested, and configures a counterweight end sliding module of the same weight based on the weighing result of the model end sliding module; S102, selecting a sensor and an elastic member according to preset test conditions, wherein the test conditions include at least one of a test object, a test distance, a test acceleration and deceleration law, and a test number; S103 assembling the aerodynamic drag and inertia force mechanical decoupling device of the dynamic model according to preset installation steps; S104: performing an aerodynamic drag measurement test according to preset test conditions, and deriving the aerodynamic drag of the sliding module at the model end using the following formula; , and when , hour, ; in, is the acceleration; is the weight of the sliding module at the model end; is the weight of the sliding module at the counterweight end; is the force measured by the sensor; is the actual aerodynamic resistance of the test model to be tested; It is the force arm of the model end sliding module around the rotating fulcrum on the balance rod in the mechanical decoupling device of the aerodynamic resistance and inertial force of the dynamic model; The sliding module at the counterweight end revolves around the lever arm of the rotating fulcrum on the balance rod in the mechanical decoupling device of the aerodynamic resistance and inertial force of the dynamic model.

9. A method for mechanically decoupling aerodynamic drag and inertial force of a dynamic model according to claim 8, characterized in that: In step S102, the specific steps of selecting the elastic member include: S1021 calculates the total maximum inertia force of the sliding module at the model end and the sliding module at the counterweight end according to the maximum deceleration by using the following formula; ； in, is the maximum inertia force, is the measured weight of the dynamic model module; is the desired weight of the sliding module at the counterweight end; is the maximum deceleration; S1022 uses the calculated maximum inertia force as a reference, multiplying the maximum inertia force by a preset threshold value to obtain a minimum total preload force ; S1023 is based on the minimum total preload , select the preload component using the following formula: ； Where x is the tensile length of the preloaded component; k is the stiffness coefficient of the preloaded component; F0 is the initial tension of the preloaded component; Fpreload = / N, N is the number of preloaded components.

10. A method for mechanically decoupling aerodynamic drag and inertial force of a dynamic model according to claim 9, characterized in that: In step S102, the specific steps of selecting the sensor include: S1024, based on the known drag coefficient, calculate the maximum aerodynamic drag using the following formula: ； In the formula, is the drag coefficient; is the maximum aerodynamic resistance; is the air density; is the maximum operating speed; s is the reference area; S1025 determines a maximum force value and a minimum force value; wherein the minimum force value is the maximum aerodynamic resistance, and the maximum force value is the resultant force value of the maximum inertial force, the minimum total preload force, and the maximum aerodynamic resistance; S1026 determines the range of the sensor according to the maximum force value and the minimum force value, and selects a sensor with the range.

Images