A multi-method model push-pull characteristic measurement system and measurement method

Abstract

The present invention relates to the technical field of wind tunnel testing, and particularly to a multi-method model thrust and drag characteristic measurement system and a measurement method. The system includes a pulsed wind tunnel, a suspension device, a stopping device, and a model to be measured. An accelerometer assembly and an off-line data acquisition device are embedded in the model. The suspension device includes a frame and two groups of suspension wires for suspending the model. The stopping device includes a safety support rod for stopping the model after the wind tunnel test. The safety support rod is provided with an optical displacement measurement module and an adjustment mechanism. The optical displacement measurement module is used to detect the displacement of the model during the effective test time, and the adjustment mechanism is used to drive the optical displacement measurement module to move along the axial direction of the safety support rod to adjust the distance between the optical displacement measurement module and the model. The present invention can improve the frequency response and achieve the accurate determination of the thrust and drag characteristics of the model in a pulsed wind tunnel in a short time.

Description

Technical Field

[0001] The present invention relates to the technical field of wind tunnel tests, and particularly to a multi-method model thrust and drag characteristic measurement system and a measurement method. Background Art

[0002] Pulse wind tunnels have become ideal ground test equipment for predicting and evaluating high Mach number aerodynamic performance due to their ability to simulate high Mach numbers, high total temperatures, and high total pressures simultaneously. However, due to the limitations of their operating principles, the effective test time of pulse wind tunnels is only on the order of milliseconds, and it is extremely challenging to conduct aerodynamic tests within such a short time.

[0003] Existing aerodynamic thrust and drag characteristic measurements usually use a ventral support box balance to measure thrust and drag. A box balance is installed on the abdomen of the model, and the bottom of the box balance is arranged in the wind tunnel through an abdominal support structure. However, this measurement device belongs to a cantilever beam in terms of configuration, and the measurement result has a low frequency response, making it difficult to accurately measure the aerodynamic signal within a short time. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-method model thrust and drag characteristic measurement system and a measurement method for at least some of the above deficiencies, so as to improve the measurement frequency response and data credibility.

[0005] To achieve the above purpose, the present invention provides a multi-method model thrust and drag characteristic measurement system, including:

[0006] A pulse wind tunnel, a suspension device, a stop device, and a model to be measured;

[0007] The pulse wind tunnel is used to provide a test flow field;

[0008] The model is embedded with an accelerometer combination and an off-line data acquisition device. The accelerometer combination includes at least one accelerometer, and the off-line data acquisition device is connected to each accelerometer and is used to collect and store the measurement results of the accelerometer;

[0009] The suspension device includes a frame and two groups of suspension wires. The top ends of the suspension wires are connected to the frame, and the bottom ends are connected to the model. The two groups of suspension wires are parallel and spaced apart, and the length of the suspension wires is not less than 1 m;

[0010] The stop device includes a safety support rod for stopping the model after the wind tunnel test;

[0011] A cavity that is concave inward from the tail of the model towards the head of the model is provided for the safety support rod to be inserted from the rear, and a stop groove is provided on the inner side wall of the cavity;

[0012] On the outer side of the safety support rod, there is a stop block that matches the stop groove, which is used to insert into the stop groove after the front section area of the safety support rod is inserted into the cavity, and the distance between the wall surface of the stop groove and the surface of the stop block along the axis direction of the model is smaller than the distance between the end wall of the cavity and the front end face of the safety support rod;

[0013] The safety support rod is also provided with an optical displacement measurement module and an adjustment mechanism. The optical displacement measurement module is movably arranged inside the front section area of the safety support rod through the adjustment mechanism, downstream of the front end face of the safety support rod. The optical displacement measurement module is used to detect the displacement of the model during the effective test time through the detection hole opened on the front end face of the safety support rod. The adjustment mechanism is used to drive the optical displacement measurement module to move along the axis of the safety support rod to adjust the distance between the optical displacement measurement module and the model.

[0014] Optionally, a tail stop block is also provided at the tail of the model. The tail stop block is used to be fixed behind the stop block after the stop block is inserted into the stop groove.

[0015] Optionally, the safety support rod includes a rod body and a hollow rod end;

[0016] The rod end has a stepped variable diameter structure, with the front diameter larger than the rear diameter; a end cover is provided at the front end of the rod end, and a detection hole is opened on the end cover; a front end chute is also opened on the side wall surface of the front section area of the rod end; the rear end of the rod end is connected to the rod body; a rear end chute is opened on the side wall surface of the rear section area of the rod end; both the front end chute and the rear end chute extend along the axis of the safety support rod;

[0017] The adjustment mechanism includes a pre-tightening spring, a first stop block, a second stop block and a fine adjustment nut; the pre-tightening spring, the first stop block and the second stop block are all arranged inside the rod end;

[0018] The pre-tightening spring is located between the end cover and the first stop block; the first stop block is a hollow structure, with the detection head of the optical displacement measurement module embedded inside, and a first convex block protruding outward is provided outside. The first convex block matches the front end chute, inserts into the front end chute and can slide along the front end chute;

[0019] The second stop block is inserted behind the first stop block. A second convex block protruding outward is provided outside the second stop block. The second convex block matches the rear end chute, inserts into the rear end chute and can slide along the rear end chute, and in the rear section area of the rod end, the second convex block extends out of the rear end chute;

[0020] The fine-tuning nut is sleeved outside the rear section of the end of the support rod and is located behind the second stop block.

[0021] Optionally, in the suspension device, a set of suspension wires is a vertical wire or two oblique suspension wires;

[0022] If a set of suspension wires is a vertical wire, the vertical wire is located in the plane formed by the axial direction of the model and the direction of gravity;

[0023] If a set of suspension wires is two oblique suspension wires, the two oblique suspension wires are symmetric with respect to the plane formed by the axial direction of the model and the direction of gravity.

[0024] Optionally, the system further includes:

[0025] A photographing subsystem, which is used to photograph the displacement process of preset marking points outside the model during the pulse wind tunnel test through an observation window arranged on the side wall of the pulse wind tunnel.

[0026] Optionally, the stop device further includes an angle-of-attack mechanism, and the safety support rod is arranged in the pulse wind tunnel through the angle-of-attack mechanism.

[0027] Optionally, the model is made in the following manner:

[0028] Obtain the wind tunnel flow field parameters and the geometry and dimensions of the model to be made;

[0029] Based on the wind tunnel flow field parameters and the geometry and dimensions of the model, estimate the magnitude of the aerodynamic force and the region where the center of pressure is located on the model in the wind tunnel flow field through finite element simulation;

[0030] Based on the estimated magnitude of the aerodynamic force on the model in the wind tunnel flow field, the preset angle change threshold, and the effective test time, determine the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model; the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model includes multiple combinations of the moment of inertia and the distance from the center of pressure to the center of mass whose attitude changes do not exceed the angle change threshold within the effective test time;

[0031] Based on the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model, determine the combined design range of the mass, moment of inertia, and distance from the center of pressure to the center of mass of the model through the relationship between the moment of inertia and the mass; the combined design range of the mass, moment of inertia, and distance from the center of pressure to the center of mass of the model includes multiple combinations of the mass, moment of inertia, and distance from the center of pressure to the center of mass whose attitude changes do not exceed the angle change threshold within the effective test time;

[0032] Through a multi-objective optimization method, select the data values of the mass, moment of inertia, and distance from the center of pressure to the center of mass of the model within the combined design range of the mass, moment of inertia, and distance from the center of pressure to the center of mass of the model;

[0033] Based on the estimated area where the model's center of pressure is located and the data values of the mass, moment of inertia, and distance from the center of pressure to the center of mass of the selected model, determine the mass distribution of the model;

[0034] Based on the geometric shape and dimensions, fabricate the model shell;

[0035] According to the determined mass distribution of the model, set corresponding weights inside the fabricated model shell to obtain the model entity;

[0036] Based on the final measured parameters, the actual parameters of the model entity, and the wind tunnel flow field parameters, determine the accelerometer combination; the determination of the accelerometer combination includes determining the number of accelerometers, the final measured parameters corresponding to each accelerometer, the expected installation positions, the measurement ranges, and the measurement accuracies;

[0037] According to the determined accelerometer combination, embed the accelerometer combination and the off-line data acquisition device in the model entity, and finally obtain the model for testing; the off-line data acquisition device is connected to each of the accelerometers and is used to collect and store the measurement results of the accelerometers.

[0038] Optionally, the accelerometer combination in the model includes:

[0039] One accelerometer disposed at the center of mass of the model, and / or

[0040] Two identical single-axis accelerometers respectively disposed on the left and right sides of the center of mass of the model, and / or

[0041] Two identical single-axis accelerometers respectively disposed above and below the center of mass of the model, for measuring and resolving the acceleration in the axial direction of the model.

[0042] The present invention also provides a multi-method model thrust and drag characteristic measurement method, implemented by using the multi-method model thrust and drag characteristic measurement system as described in any one of the above, including the following steps:

[0043] Obtain the model parameters and the wind tunnel flow field parameters, and estimate the displacement range of the model within the effective test time according to the model parameters and the wind tunnel flow field parameters;

[0044] Through a suspension device, suspend the model to be measured in the pulse wind tunnel in a preset posture;

[0045] Based on the estimated displacement range of the model within the effective test time, adjust the positional relationship between the stop device and the model;

[0046] Based on the estimated displacement range of the model within the effective test time, fine-tune the distance between the optical displacement measurement module and the tail of the model through an adjustment mechanism;

[0047] Start the pulsed wind tunnel to obtain the measurement results of each accelerometer in the accelerometer assembly and the optical displacement measurement module within the effective test time;

[0048] Based on the measurement results of each accelerometer obtained, calculate the aerodynamic load in the drag direction of the model in the pulsed wind tunnel flow field;

[0049] Based on the measurement results of the optical displacement measurement module, verify the calculated aerodynamic load.

[0050] Optionally, suspending the model to be measured in the pulsed wind tunnel in a preset posture through the suspension device includes:

[0051] Adjust the axis of the frame to be horizontal;

[0052] Adjust the axis of the model to be horizontal and fix the model through the temporary support device;

[0053] Add an installation reference block outside the front end face of the safety support rod, insert the safety support rod into the cavity at the tail of the model, and initially adjust the coaxiality of the safety support rod and the model;

[0054] Connect a set of suspension wires of the suspension device from the frame perpendicular to the axis of the model to the position on the head of the model with the least interference to the flow field, and connect the other set of suspension wires from the frame perpendicular to the axis of the model to the end face of the tail of the model, and lift the model;

[0055] Remove the temporary support device;

[0056] By changing the posture of the frame, adjust the posture of the model to the preset posture and correspondingly adjust the posture of the safety support rod;

[0057] Keep the model in the suspended state, move the model forward, remove the installation reference block, and then put the model back.

[0058] The above technical solution of the present invention has the following advantages: The present invention provides a multi-method model thrust and drag characteristic measurement system and measurement method. The present invention suspends the model in the flow field of the pulsed wind tunnel, making the model in a zero-stiffness support state in the drag direction, which can effectively improve the measurement frequency response. At the same time, the measurement system of the present invention has a more compact structure and higher stiffness, which can reduce the interference of difficult-to-handle low-frequency interference on the model aerodynamic measurement signal, improve the data credibility, so as to more accurately measure the instantaneous aerodynamic signal in the millisecond order, and can realize multi-method simultaneous measurement, reducing the number of repeated tests. Description of the Drawings

[0059] Figure 1 is a schematic structural diagram of a multi-method model thrust and drag characteristic measurement system in an embodiment of the present invention;

[0060] Figure 2 It is a schematic cross-sectional view of the front section structure of a safety strut in an embodiment of the present invention;

[0061] Figure 3 It is an exploded view of the front section structure of a safety strut in an embodiment of the present invention;

[0062] Figure 4 It is an exploded view of the front section structure of the safety strut from another perspective;

[0063] Figure 5 It is a schematic diagram of the steps of a multi-method model thrust and drag characteristic measurement method in an embodiment of the present invention.

[0064] In the figure: 1: Wind tunnel nozzle; 2: Wind tunnel test chamber; 3: Frame; 4: Suspension wire; 5: Safety strut; 6: Angle of attack mechanism; 7: Observation window; 8: Model; 9: Pressure measuring device;

[0065] 51: End cap; 511: Detection hole; 52: Preloading spring; 53: First stop block; 54: Optical displacement measurement module; 55: Second stop block; 56: Fine adjustment nut; 57: Strut end; 571: Front end chute; 572: Rear end chute; 58: Stop block; 81: Tail stop block. Specific embodiments

[0066] 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.

[0067] Currently, the commonly used measurement of aerodynamic drag characteristics usually adopts the technique of measuring drag and thrust using a belly-supported balance. A balance is installed on the belly of the model, and the bottom of the balance is arranged in the wind tunnel through a belly support structure, and the aerodynamic force applied to the model is measured by the balance. The belly-supported balance drag and thrust measurement technique belongs to the static force measurement technique in principle. Due to the limitation of the operating principle, the effective test time of the pulsed wind tunnel is generally only a few hundred microseconds to several tens of milliseconds, and the whole process belongs to the dynamic test process, and the vibration interference is prominent. Since the belly-supported balance drag and thrust measurement device belongs to a cantilever beam in configuration, the measurement is affected by the natural vibration frequency, and it is difficult to accurately measure the aerodynamic force load in the millisecond range. The present invention provides a multi-method model drag and thrust characteristic measurement system and measurement method, which reduces the influence of vibration interference on the measurement result of the model aerodynamic force in the form of zero-stiffness support, improves the frequency response, and can realize multi-method simultaneous measurement. Compared with the traditional single-method multi-vehicle measurement data verification method, it can reduce the number of repeated vehicles and ensure the data credibility at the same time.

[0068] The following describes the specific implementation manners of the above concepts.

[0069] As Figure 1 shown, a multi-method model drag and thrust characteristic measurement system provided by an embodiment of the present invention includes a pulsed wind tunnel, a suspension device, a stop device, and a model to be measured; specifically, among them,

[0070] The pulsed wind tunnel is used to provide a test flow field;

[0071] The model is embedded with an accelerometer combination and an off-line data acquisition device; the accelerometer combination includes at least one accelerometer, and the off-line data acquisition device is connected to each accelerometer and is used to collect and store the measurement results of the accelerometer; that is to say, during the test, there is no need to externally connect a power line or a data transmission line to the model, and the corresponding data is obtained through the accelerometer combination and the off-line data acquisition device embedded in the model, and the stored data is read after the test for calculation;

[0072] The suspension device includes a frame 3 and two groups of suspension lines 4. The top ends of the suspension lines 4 are connected to the frame 3, and the bottom ends of the suspension lines 4 are connected to the model 8. The two groups of suspension lines 4 are parallel and spaced apart. That is, the spacing distance between the top suspension points of the two groups of suspension lines 4 (that is, the positions where the two groups of suspension lines are respectively connected to the frame) is the same as the spacing distance between the bottom suspension points of the two groups of suspension lines 4 (that is, the positions where the two groups of suspension lines are respectively connected to the model). Looking from the side, the two groups of suspension lines 4 are both vertically downward and are arranged one in front of the other in the wind tunnel; the length of the suspension line 4 is not less than 1 m; the orientation words "top" and "bottom" in this part both represent the orientation relative to the ground;

[0073] The stopping device includes a safety support rod 5, which is used to stop the model after the wind tunnel test to prevent the subsequent airflow from continuously acting on the model, resulting in the model flying randomly in the test section of the impulse wind tunnel and colliding;

[0074] A cavity concave inward in the direction of the head of the model 8 is provided at the tail of the model 8, which is used to insert the safety support rod 5 from the rear. A stopping groove is provided on the inner side wall of the cavity;

[0075] A stopping block 58 matching the stopping groove is provided on the outer side of the safety support rod 5, which is used to insert into the stopping groove after the front section area of the safety support rod 5 is inserted into the cavity. Along the axis direction of the model 8, the distance between the wall surface of the stopping groove and the surface of the stopping block 58 is smaller than the distance between the end wall of the cavity and the front end face of the safety support rod 5; Here, the azimuth term "front" means relatively close to the oncoming flow direction, that is, upstream, and "rear" means relatively far from the oncoming flow direction, that is, downstream;

[0076] The safety support rod 5 is also provided with an optical displacement measurement module 54 and an adjustment mechanism. The front section area of the safety support rod 5 is a hollow structure. The optical displacement measurement module 54 is movably arranged inside the front section area of the safety support rod 5 through the adjustment mechanism. The optical displacement measurement module 54 is used to detect the displacement of the model during the effective test time through a detection hole 511 opened on the front end face of the safety support rod 5. The adjustment mechanism is used to drive the optical displacement measurement module 54 to move along the axis of the safety support rod 5 to adjust the distance between the optical displacement measurement module 54 and the model. For the convenience of the optical displacement measurement module 54 to detect, the diameter of the detection hole 511 should not be too small to avoid occlusion.

[0077] The multi-method model thrust and drag characteristic measurement system (hereinafter referred to as the system) provided by the present invention uses a pulsed wind tunnel to provide the test flow field. The model to be measured is hung in the flow field area of the pulsed wind tunnel through a suspension device. Since the length of the suspension wire is long and the effective test time is very short, within the effective test time of the millisecond level, the model displacement is only of the millimeter level, which is almost negligible compared to the meter-level suspension wire. The influence of the suspension wire tension on the model drag can be ignored. That is, within the effective test time, the model can be approximately regarded as being in a free motion state in the drag direction, which means the model is in a zero-stiffness support state, avoiding the vibration interference introduced by the cantilever beam structure in the existing measurement system, making the entire measurement system more compact and having higher stiffness, thereby greatly increasing the natural vibration frequency and the upper limit of the frequency response of the system, and enabling the accurate determination of the model thrust and drag characteristics in the pulsed wind tunnel in a short time to solve the problem of aerodynamic force measurement in the millisecond level; and, since the method of hanging with two groups of suspension wires is adopted, the head and tail of the model can be hung separately, which is safer and more reliable, and can be applied to overweight and oversized models such as engine models that have scale effects and require 1:1 simulation tests; in addition, the safety support rod 5 is inserted into the tail of the model 8. Along the axial direction of the model 8, the distance between the wall surface of the stop groove and the surface of the stop block 58 is smaller than the distance between the end wall of the cavity and the front end surface of the safety support rod 5. When the model 8 moves, the stop groove and the stop block 58 collide first, and after the wind tunnel test ends, it can timely resist the model 8 to stop the model 8, improving the test safety; at the same time, the optical displacement measurement module 54 provided in the safety support rod 5 can also measure the displacement size of the model during the effective test time, so as to calibrate the measurement and calculation results of the accelerometer embedded in the model 8, realize multi-method simultaneous measurement, reduce the number of repeated test trips, and ensure the data credibility at the same time. The optical displacement measurement module 54 is located inside the safety support rod and at a position downstream of the front end surface of the safety support rod, avoiding the optical displacement measurement module 54 from colliding with the bottom of the model and being damaged. The measurement principle involved in the present invention can be expressed as:

[0078] F = ma

[0079]

[0080] where, F represents the aerodynamic force, m represents the mass of the model, a represents the acceleration suffered by the model, l represents the displacement of the model, t represents the effective test time, and a t represents the acceleration of the model in the drag direction and is related to the effective test time t.

[0081] In addition, the present invention also integrates optical elements and circuit elements required for high-precision optical displacement measurement, etc. into the optical displacement measurement module 54, which is arranged inside the safety support rod 5, can play a protective role, and is easy to install. The optical displacement measurement module 54 can adopt a high-precision displacement sensor, and the accurate measurement range can be 1 mm to 3 mm. Considering that the displacement of the model in the test is very small, in order to accurately measure the effective displacement, it is necessary to finely adjust the position of the optical displacement measurement module 54. Therefore, the present invention provides an adjustment mechanism to move the optical displacement measurement module 54 to a suitable position before the test starts.

[0082] Optionally, the stop block 58 is the actual collision point during the retraction prevention process, and anti-collision materials such as polyurethane can be arranged before and after it for shock absorption. The shape of the stop block 58 can be designed according to needs. When the model has a large rolling moment and may thus undergo rolling motion, the stop block 58 can be designed as a square to achieve the effect of preventing rolling. Correspondingly, the stop groove matching the stop block 58 should also be designed as a square.

[0083] Adopting the above embodiment, before the test starts, the front end of the safety support rod 5 is inserted into the cavity at the tail of the model but does not directly contact the model, and there is a certain gap between the front end of the safety support rod 5 and the end wall of the cavity. Since the safety support rod 5 extends into the model and is closer to the centroid position of the model, it can effectively stop the model after the test. The stop block 58 is inserted into the stop groove and cooperates with the stop groove, which can enable the safety support rod 5 to not only prevent the model from retreating axially but also play a role in preventing rotation and prevent the model from deflecting. In some embodiments, on the upper and lower sides (such as Figure 1 the shown orientation, relative to the ground) of the inner side wall of the cavity at the tail of the model, non-communicating stop grooves can be respectively opened. Correspondingly, on the upper and lower sides of the safety support rod 5, stop blocks 58 matching the corresponding stop grooves are also respectively provided. In some other embodiments, as Figures 2 to 4 shown, the stop block 58 can also be arranged circumferentially along the safety support rod 5, protruding outward (i.e., the side relatively far from the axis). Correspondingly, the inner wall of the cavity is provided with a stop groove that is recessed circumferentially away from the axis. In some other embodiments, a protruding stop block 58 can also be provided on the inner wall of the cavity and a recessed stop groove can be provided on the outside of the safety support rod 5.

[0084] Optionally, a tail stop 81 is also provided at the tail of the model. The tail stop 81 is used to be fixed behind the stop block 58 after the stop block 58 is inserted into the stop groove. That is to say, after the stop block 58 is correspondingly inserted into the stop groove, a tail stop 81 can also be provided at the edge of the stop groove where the stop block 58 is inserted from the rear of the model (i.e., the side relatively far from the oncoming flow). After the tail stop 81 is provided, even if the model has a tendency to move forward under the action of the flow field, it can stop moving under the restriction of the stop block 58 and the tail stop 81, avoiding random flying. A certain gap should also be left between the tail stop 81 and the stop block 58 in the axial direction to prevent the model from contacting the safety support rod 5, thereby affecting the movement of the model.

[0085] As Figures 2 to 4 shown, in some embodiments, the safety support rod 5 includes a rod body and a hollow rod end 57; wherein,

[0086] the rod end 57 has a stepped variable diameter structure, and the diameter of the front section of the rod end 57 is larger than the diameter of the rear section of the rod end 57; a end cover 51 is provided at the front end of the rod end 57 (i.e., the end relatively close to the model after insertion), and a detection hole 511 is opened on the end cover 51; a front end chute 571 is also opened on the side wall surface of the front section area of the rod end 57; the rear end of the rod end 57 (i.e., the end relatively far from the model) is connected to the rod body, and the rod body can be a solid or hollow structure; a rear end chute 572 is opened on the side wall surface of the rear section area of the rod end 57; both the front end chute 571 and the rear end chute 572 extend along the axis of the safety support rod 5 for limiting; preferably, the front end chute 571 and the rear end chute 572 of the rod end 57 are not connected to increase the stiffness of the rod end 57;

[0087] the adjusting mechanism includes a pre-tightening spring 52, a first stop block 53, a second stop block 55 and a fine-tuning nut 56; the pre-tightening spring 52, the first stop block 53 and the second stop block 55 are all arranged inside the rod end 57;

[0088] the pre-tightening spring 52 is located between the end cover 51 and the first stop block 53 for providing a thrust force; the first stop block 53 is a hollow structure, and the detection head of the optical displacement measurement module 54 is embedded inside the first stop block 53. An outward (i.e., relatively far from the axis direction) protruding first convex block is provided outside the first stop block 53, and the first convex block matches the front end chute 571, is inserted into the front end chute 571 and can slide along the front end chute 571;

[0089] The second stop block 55 is inserted behind the first stop block 53. An outwardly protruding second convex block is provided on the outside of the second stop block 55. The second convex block is matched with the rear end chute 572, inserted into the rear end chute 572 and can slide along the rear end chute 572. And in the rear section area of the rod end 57, the second convex block extends out of the rear end chute 572. That is to say, the diameter of the rear section area of the rod end 57 is smaller than the circumscribed circle diameter of the second stop block 55, and the second convex block can protrude above the rear section area of the rod end 57 so as to adjust the position of the second stop block 55 from the outside; the cables required by the optical displacement measurement module 54 can pass through the openings of the first stop block 53 and the second stop block 55 and extend into the safety rod for leading out;

[0090] The fine adjustment nut 56 is sleeved on the outside of the rear section area of the rod end 57 and is located at the rear side of the second stop block 55 for limiting the second stop block 55. Optionally, the stop block 58 is sleeved at the diameter-changing part of the rod end 57, and the tail stop block 81 is arranged at the rear side of the stop block 58. Further, considering that the fine adjustment nut 56 is sleeved on the outside of the rear section area of the rod end 57, external threads matching the fine adjustment nut 56 should be provided on the outside of the rear section area of the rod end 57, and the rear end chute 572 also extends to the rear section area of the rod end 57. Therefore, it is preferably to machine the external threads first and then open the rear end chute 572 during processing to ensure the matching relationship between the formed partition external threads and the fine adjustment nut 56.

[0091] In some other embodiments, the safety rod includes a hollow inner rod and a housing sleeved on the front end of the inner rod; a detection hole is opened at the front end of the housing, and the stop block is arranged on the outer side of the housing; a chute along the axial direction of the inner rod is opened in the front section area of the inner rod, and after the housing is fixed at the front end of the inner rod, the chute extends out of the area blocked by the housing. That is to say, the chute will not be completely surrounded and covered by the housing;

[0092] The adjusting mechanism includes a pre-tightening spring, a first stop block, a second stop block and a fine adjustment nut; wherein, the pre-tightening spring is arranged between the first stop block and the front end of the housing; the first stop block is arranged at the front end of the inner rod, the detection head of the optical displacement measurement module is embedded in the hollow first stop block, and a convex block matching the chute is arranged on the outside of the first stop block and can be inserted into the chute and slide along the chute;

[0093] The second stop block is arranged inside the inner rod for pushing the first stop block. A convex block matching the chute is arranged on the outside of the second stop block and can penetrate out of the chute from the inside of the inner rod and can slide along the chute;

[0094] The fine-tuning nut is sleeved outside the inner rod and is located behind the outer shell, and is used to push the bump of the second stopper from the outside so as to adjust the positions of the second stopper and the optical displacement measurement module.

[0095] Since the front end of the safety support rod 5 extends into the cavity inside the tail of the model, and the optical displacement measurement module 54 is inside the safety support rod 5, so as to prevent the model from hitting the safety support rod 5 and damaging the optical displacement measurement module 54, this makes it difficult to directly adjust the position of the optical displacement measurement module 54 from the outside. The adjustment mechanism adopted by the present invention includes a pre-tightening spring 52, a first stopper 53, a second stopper 55 and a fine-tuning nut 56. The probe of the optical displacement measurement module 54 is embedded in the first stopper 53 and can move along with the first stopper 53. The probe detects the displacement of the model in front of the safety support rod 5 through the detection hole 511. The circuits and other devices of the optical displacement measurement module 54 can be arranged inside the first stopper 53 and the second stopper 55, and the required cables can pass through the openings of the first stopper 53 and the second stopper 55 and extend into the safety support rod to be led out. Through the corresponding cooperation of the sliding groove and the bump, the first stopper 53 and the second stopper 55 can move linearly along the axis of the safety support rod 5 without rotation, so as to prevent the optical displacement measurement module 54 from deflecting during the adjustment process and affecting the measurement result. The pre-tightening spring 52 provides a thrust force from the front side to the rear side of the optical displacement measurement module 54. The fine-tuning nut 56 is sleeved on the rear side of the optical displacement measurement module 54 and is used for limiting, and the adjustment can be carried out from the outside. By screwing in the fine-tuning nut 56, the probe of the optical displacement measurement module 54 can be pushed forward. When the fine-tuning nut 56 is loosened in the reverse direction and the fine-tuning nut 56 moves backward, the pre-tightening spring 52 will push the probe of the optical displacement measurement module 54 backward to realize the fine adjustment of the position of the optical displacement measurement module 54.

[0096] Optionally, in the suspension device, a set of suspension wires 4 is a vertical wire or two inclined suspension wires; if a set of suspension wires 4 is a vertical wire, when the model is suspended, the vertical wire is located in the plane formed by the axis of the model and the direction of gravity; if a set of suspension wires 4 is two inclined suspension wires, when the model is suspended, the two inclined suspension wires are symmetric with respect to the plane formed by the axis of the model and the direction of gravity, and the bottom suspension points of the two inclined suspension wires are connected at the same place or the distance between the top suspension points between the two inclined suspension wires is greater than the distance between the bottom suspension points.

[0097] The above embodiments provide two ways to suspend the model. When using two vertical lines for suspension, the interference to the model flow field is small. Only the normal force and pitching moment are not in the zero-stiffness support state. Looking at the model, the suspension line 4, the top surface of the middle test section of the model, and the frame 3 approximately form a rectangle from the side. When adjusting the attitude of the model, the attitude of the frame 3 is changed, and the model changes accordingly. Looking at the model, the suspension line 4, the top surface of the middle test section of the model, and the frame 3 approximately form a parallelogram from the side. In the case of no normal force and pitching moment, the model translates, and the attitude hardly changes, so as to reduce the influence of suspension on the force of the model and ensure that the force on the model remains basically unchanged within the effective test time. When using four oblique suspension lines for suspension, from the side, the two oblique suspension lines are indistinguishable from one vertical line. Looking from the front, the two oblique suspension lines form a V shape, which has good stability in the thrust and drag directions. The model is not easily deflected in the wind tunnel. Even if there is a slight deviation between the oncoming flow direction of the test flow field and the axis of the wind tunnel, the model can still remain stable, and the rotation that occurs within the effective test time can be ignored. It can be applied to the suspension measurement of large-inertia and heavy models such as scramjet models.

[0098] Optionally, the system provided by the present invention further includes a photographing subsystem. The photographing subsystem is used to photograph the displacement process of the preset marking points outside the model 8 during the pulse wind tunnel test through the observation window 7 provided on the side wall of the pulse wind tunnel to determine the displacement of the model 8.

[0099] The above embodiments use the photographing subsystem to take pictures. The displacement of the model can be measured simultaneously by optical means such as schlieren in cooperation with the marking point recognition algorithm, realizing multi-method and multi-angle simultaneous measurement, reducing the number of repeated train trips while ensuring the credibility of the data.

[0100] Optionally, as Figure 1 shown, the stopping device further includes an angle of attack mechanism 6. The safety support rod 5 is arranged in the pulse wind tunnel through the angle of attack mechanism 6.

[0101] The above embodiments use the existing angle of attack mechanism 6 to install the safety support rod 5, which can align the axis of the safety support rod 5 with the axis of the model and have a certain gap from the model. The angle of attack mechanism 6 is easy to adjust and has little influence on the wind tunnel flow field.

[0102] As Figure 1As shown, when the system is used, the model 8 is suspended by the suspension line 4 in the wind tunnel test chamber 2 and placed behind the wind tunnel nozzle 1. The accelerometer combination built into the model 8 can be used to detect and obtain a set of data and solve the force in the direction of resistance. The safety support rod 5 is installed behind the model 8 through the angle of attack mechanism 6. The optical displacement measurement module 54 at the front end of the safety support rod 5 can be used to detect and obtain a set of data and solve the force in the direction of resistance. At the same time, the shooting subsystem outside the observation window 7 is used to shoot the model motion image, which can also detect and obtain a set of data and solve the force in the direction of resistance. Compared with the traditional single method multi-trip measurement data verification method, the number of repeated trips can be reduced, while ensuring the credibility of the data. Preferably, the system also includes a pressure measuring device 9 for measuring the flow field pressure provided by the pulse wind tunnel.

[0103] Considering that the model is suspended in the flow field and has a high degree of freedom, in order to avoid deflection or shaking of the model during the effective test time, which may lead to inaccurate aerodynamic measurement results, preferably, the model to be measured can be made by the following method:

[0104] Obtain wind tunnel flow field parameters and the geometric shape and size of the model to be made;

[0105] Based on the wind tunnel flow field parameters and the geometric shape and size of the model, the magnitude of the aerodynamic force on the model in the wind tunnel flow field and the area where the pressure center is located are estimated through finite element simulation;

[0106] Based on the estimated magnitude of the aerodynamic force on the model in the wind tunnel flow field, the preset angle change threshold and the effective test time, the combined design range of the model's moment of inertia and the distance from the center of pressure to the center of mass is determined; the combined design range of the model's moment of inertia and the distance from the center of pressure to the center of mass includes multiple combinations of moment of inertia and distance from the center of pressure to the center of mass data whose attitude changes do not exceed the angle change threshold within the effective test time;

[0107] Based on the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model, the combined design range of the mass, moment of inertia and the distance from the center of pressure to the center of mass of the model is determined through the relationship between the moment of inertia and the mass; the combined design range of the mass, moment of inertia and the distance from the center of pressure to the center of mass of the model includes multiple combinations of mass, moment of inertia and distance from the center of pressure to the center of mass data whose posture changes do not exceed the angle change threshold within the effective test time;

[0108] Through the multi-objective optimization method, the data values ​​of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model are selected within the combined design range of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model;

[0109] Determine the mass distribution of the model based on the estimated area where the model's center of pressure is located and the selected model's mass, moment of inertia, and distance from the center of pressure to the center of mass data values;

[0110] Fabricate a model housing based on the described geometry and dimensions;

[0111] According to the determined mass distribution of the model, set corresponding counterweights inside the fabricated model housing to obtain a model entity;

[0112] Based on the final measurement parameters, the actual parameters of the model entity, and the wind tunnel flow field parameters, determine the accelerometer combination; the determination of the accelerometer combination includes determining the number of accelerometers, the final measurement parameters corresponding to each accelerometer, the expected installation positions, the measurement ranges, and the measurement accuracies;

[0113] According to the determined accelerometer combination, embed the accelerometer combination and the off-line data acquisition device in the model entity to finally obtain a model for testing; the off-line data acquisition device is connected to each of the accelerometers and is used to collect and store the measurement results of the accelerometers.

[0114] Through the above method, a model with good stability can be fabricated. The model is not prone to attitude changes during the test, so as to adapt to zero-stiffness support measurement. If each set of suspension wires suspends the model with a vertical wire, the final measurement parameters may include one or more of the axial force and lateral force, yaw moment, and roll moment. If each set of suspension wires suspends the model with two oblique suspension wires, the final measurement parameter only includes the axial force.

[0115] Optionally, the accelerometer combination in the model includes:

[0116] An accelerometer disposed at the center of mass of the model, and / or

[0117] Two identical single-axis accelerometers respectively disposed on the left and right sides of the center of mass of the model, and / or

[0118] Two identical single-axis accelerometers respectively disposed above and below the center of mass of the model, which are used to measure and calculate the acceleration in the axial direction of the model.

[0119] Measure the axial acceleration of the model through two accelerometers respectively disposed on the left and right or above and below the center of mass of the model. The measurement results are added to obtain twice the axial acceleration. Combined with the accelerometer disposed at the center of mass of the model, the acceleration measurement results can be verified. Theoretically, the axial rigid body acceleration of the model can be measured through the accelerometer disposed at the center of mass of the model. Considering that the vibration characteristics at different positions of the model are different, more accelerometers can be arranged. The vibration interferences sensed by different accelerometers are different, but the rigid body accelerations of the model sensed are the same. Using this mechanism, the same output components in each accelerometer can be analyzed, so as to be used to distinguish the vibration interference components in the signal. According to the preset attitude of the model, the acceleration in the resistance direction of the model can be calculated from the measured axial acceleration of the model.

[0120] Each accelerometer is arranged inside the model through an accelerometer mounting seat. Further, in order to prevent looseness of the accelerometer, a corrugated spring can be used in the model to provide the pressing force for the accelerometer mounting seat.

[0121] As Figure 5 As shown, the present invention also provides a method for measuring the thrust and drag characteristics of a multi-method model, which is implemented by using the multi-method model thrust and drag characteristic measurement system described in any one of the above embodiments. The method specifically includes the following steps:

[0122] Step 500, obtain the model parameters and the wind tunnel flow field parameters, and estimate the displacement range of the model within the effective test time according to the model parameters and the wind tunnel flow field parameters;

[0123] This step can be estimated by finite element simulation or directly according to the numerical values;

[0124] Step 502, suspend the model to be measured in the pulse wind tunnel in a preset posture through a suspension device;

[0125] Step 504, based on the estimated displacement range of the model within the effective test time, adjust the positional relationship between the stop device and the model;

[0126] Step 506, based on the estimated displacement range of the model within the effective test time, fine-tune the distance between the optical displacement measurement module and the tail of the model through an adjustment mechanism, and adjust the optical displacement measurement module to the optimal measurement position;

[0127] Step 508, turn on the pulse wind tunnel, and obtain the measurement results of each accelerometer in the accelerometer combination and the optical displacement measurement module within the effective test time;

[0128] Step 510, based on the measurement results of each accelerometer obtained, calculate the aerodynamic load in the drag direction of the model in the pulse wind tunnel flow field;

[0129] Step 512, based on the measurement results of the optical displacement measurement module, verify the calculated aerodynamic load.

[0130] Optionally, step 502 "suspend the model to be measured in the pulse wind tunnel in a preset posture through a suspension device" further includes:

[0131] Adjust the axis of the frame to be horizontal;

[0132] Adjust the axis of the model to be horizontal and fix the model through a temporary support device;

[0133] Add an installation reference block outside the front end face of the safety support rod, insert the safety support rod into the cavity at the tail of the model, and preliminarily adjust the coaxiality of the safety support rod and the model;

[0134] Connecting a set of suspension wires of the suspension device from the frame perpendicular to the axial direction of the model to the position of the head of the model that has the least interference with the flow field, and connecting another set of suspension wires from the frame perpendicular to the axial direction of the model to the tail end face of the model to suspend the model;

[0135] Removing the temporary support device;

[0136] By changing the posture of the frame, the posture of the model is adjusted to a preset posture and the posture of the safety support rod is adjusted accordingly;

[0137] The model is moved forward while being kept in the suspended state, the mounting reference block is removed, and the model is then put back.

[0138] Considering that the effective displacement of the model is very short, the safety support rod should be close to the tail of the model but cannot be in direct contact with the tail. The above embodiment uses a mounting reference block to be placed on the front end surface of the safety support rod for position adjustment. The specific thickness of the mounting reference block can be determined based on the estimated displacement range of the model within the effective test time. Since the movement time of the model within the effective test time is usually in the millimeter level, the accurate measurement distance of the optical displacement measurement module is only a few millimeters, and the thickness of the mounting reference block is usually not too thick. The front end of the safety support rod is extended into the cavity at the tail of the model, and the stop block should also be inserted into the stop groove accordingly. Due to the installation of the mounting reference block, the safety support rod can resist the model, that is, the mounting reference block is close to the end wall of the cavity at the tail of the model near the head side. After the model is suspended, the model is moved forward, the mounting reference block is removed, and the model is put back, so as to ensure that there is a certain gap between the front end of the safety support rod and the model and the gap is not too long.

[0139] Furthermore, step 502 of “suspending the model to be measured in a preset posture in the pulse wind tunnel through a suspension device” also includes:

[0140] A tail stopper is arranged behind the stop groove to prevent the stopper block inserted into the stop groove from falling out.

[0141] Optionally, step 504 of “adjusting the positional relationship between the stopper and the model” further includes:

[0142] Based on the measurement data of the optical displacement measurement module, fine-tune the axial spacing between the model and the safety support rod;

[0143] According to the calibration mark lines preset on the tail stop and the outside of the safety support rod, fine-tune the model to be coaxial with the safety support rod.

[0144] During the adjustment process, by using the feedback results of the optical displacement measurement module, the distance between the model and the front end of the safety support rod can be finely adjusted. Calibration is carried out through preset calibration marking lines. For example, by aligning the calibration marking lines on the four upper, lower, left, and right sides of the outside of the safety support rod with the calibration marking lines set circumferentially on the opening of the tail stop block through which it passes, the postures of the model and the safety support rod can be made as unified as possible, and the axes of the model and the safety support rod can be aligned.

[0145] Further, if a reference plane is reserved on the model, it may further include: arranging an inclinometer on the reserved reference plane to finely adjust the posture of the model.

[0146] Using the above embodiments can achieve fine adjustment by using the optical displacement measurement module. The optical displacement measurement module as a feedback adjustment distance can include two aspects. One is that when the position of the optical displacement sensor remains unchanged, the gap size between the model and the front end of the safety support rod can be accurately feedback. Because during the initial installation, the relative distance between the installation position of the optical displacement measurement module and the front end face of the safety support rod can be measured, and the gap size between the safety support rod and the model can be quantitatively known through the value feedback by the optical displacement measurement module. The other is that when the gap adjustment is in place, based on the estimated displacement range of the model within the effective test time, the position of the optical displacement sensor is adjusted to the optimal measurement position through the adjustment mechanism to accurately measure the displacement of the model within the effective time.

[0147] In summary, the present invention provides a multi-method model thrust and drag characteristic measurement system and measurement method. The thrust and drag characteristics of the model are measured in a suspended manner, and the measurement frequency response is improved by 2 orders of magnitude compared with the traditional box-type balance measurement scheme; the present invention sets up a safety support rod to play a role of recoil stopping, improving the test safety; an optical displacement measurement module is installed at the front end of the safety support rod to measure the displacement of the model at the same time, realizing multi-method simultaneous measurement, improving the data credibility, reducing the required test vehicle trips, and greatly improving the test efficiency.

[0148] 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 it; 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 recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-method model push-pull characteristic measurement system, characterized in that, Comprising: A pulse wind tunnel, a suspension device, a stop device, and a model to be measured; The pulse wind tunnel is used to provide a test flow field; The model is embedded with an accelerometer combination and an off-line data acquisition device. The accelerometer combination includes at least one accelerometer, and the off-line data acquisition device is connected to each accelerometer for collecting and storing the measurement results of the accelerometer; The suspension device includes a frame and two groups of suspension wires. The top ends of the suspension wires are connected to the frame, and the bottom ends are connected to the model. The two groups of suspension wires are parallel and spaced apart, and the length of the suspension wires is not less than 1 m; The stop device includes a safety support rod for stopping the model after the wind tunnel test; A cavity concave inward in the direction of the head of the model is provided at the tail of the model for the safety support rod to be inserted from the rear. A stop groove is provided on the inner side wall of the cavity; A stop block matching the stop groove is provided on the outer side of the safety support rod. After the front section area of the safety support rod is inserted into the cavity, the stop block is inserted into the stop groove, and the distance between the wall surface of the stop groove and the surface of the stop block is less than the distance between the end wall of the cavity and the front end face of the safety support rod along the axis of the model; The safety support rod is further provided with an optical displacement measurement module and an adjustment mechanism. The optical displacement measurement module is movably arranged inside the front section area of the safety support rod through the adjustment mechanism, downstream of the front end face of the safety support rod. The optical displacement measurement module is used to detect the displacement of the model during the effective test time through a detection hole provided on the front end face of the safety support rod, and the adjustment mechanism is used to drive the optical displacement measurement module to move along the axis of the safety support rod to adjust the distance between the optical displacement measurement module and the model.

2. The system according to claim 1, characterized in that, A tail stop block is further provided at the tail of the model. The tail stop block is used to be fixed behind the stop block after the stop block is inserted into the stop groove.

3. The system according to claim 1, characterized in that, The safety support rod includes a rod body and a hollow rod end; The rod end is a stepped variable diameter structure, with the front diameter larger than the rear diameter; a end cover is provided at the front end of the rod end, and a detection hole is provided on the end cover; a front end chute is further provided on the side wall surface of the front section area of the rod end; the rear end of the rod end is connected to the rod body; a rear end chute is provided on the side wall surface of the rear section area of the rod end; both the front end chute and the rear end chute extend along the axis of the safety support rod; The adjustment mechanism includes a pre-tightening spring, a first stop block, a second stop block, and a fine adjustment nut; the pre-tightening spring, the first stop block, and the second stop block are all arranged inside the rod end; The pre-tightening spring is located between the end cover and the first stop block; the first stop block is a hollow structure, with the detection head of the optical displacement measurement module embedded inside, and a first convex block protruding outward is provided outside. The first convex block matches the front end chute, is inserted into the front end chute and can slide along the front end chute; The second stop block is inserted behind the first stop block. An outwardly protruding second convex block is provided on the outside of the second stop block. The second convex block is matched with the rear end chute, inserted into the rear end chute and can slide along the rear end chute, and the second convex block extends out of the rear end chute in the rear section area of the end of the support rod. The fine-tuning nut is sleeved on the outside of the rear section area of the end of the support rod and is located behind the second stop block.

4. The system according to claim 1, characterized in that, In the suspension device, a set of suspension wires is a vertical wire or two inclined suspension wires. If a set of suspension wires is a vertical wire, the vertical wire is located in the plane formed by the axial direction of the model and the gravity direction. If a set of suspension wires is two inclined suspension wires, the two inclined suspension wires are symmetric with respect to the plane formed by the axial direction of the model and the gravity direction.

5. The system according to claim 1, characterized in that, It further includes: A shooting subsystem, which is used to shoot the displacement process of preset marking points outside the model during the pulse wind tunnel test from the outside through an observation window provided on the side wall of the pulse wind tunnel.

6. The system according to claim 1, characterized in that, The stop device further includes an angle of attack mechanism, and the safety support rod is arranged in the pulse wind tunnel through the angle of attack mechanism.

7. The system according to claim 1, characterized in that, The model is made in the following way: Obtain the wind tunnel flow field parameters and the geometric shape and size of the model to be made. Based on the wind tunnel flow field parameters and the geometric shape and size of the model, estimate the magnitude of the aerodynamic force and the area where the center of pressure is located on the model in the wind tunnel flow field through finite element simulation. Based on the estimated magnitude of the aerodynamic force on the model in the wind tunnel flow field, the preset angle change threshold and the effective test time, determine the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model; within the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model, there are multiple combinations of moment of inertia and distance from the center of pressure to the center of mass data where the attitude change does not exceed the angle change threshold within the effective test time. Based on the combined design range of the moment of inertia and the distance from the center of pressure to the center of mass of the model, determine the combined design range of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model through the relationship between the moment of inertia and the mass; within the combined design range of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model, there are multiple combinations of mass, moment of inertia and distance from the center of pressure to the center of mass data where the attitude change does not exceed the angle change threshold within the effective test time. Through a multi-objective optimization method, select the data values of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model within the combined design range of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model. Based on the estimated area where the center of pressure of the model is located and the selected data values of the mass, moment of inertia and distance from the center of pressure to the center of mass of the model, determine the mass distribution of the model. Based on the geometric shape and size, make the model shell. According to the determined mass distribution of the model, set corresponding counterweights in the made model shell to obtain the model entity. Based on the final measurement parameters, the actual parameters of the model entity and the wind tunnel flow field parameters, determine the accelerometer combination; the determination of the accelerometer combination includes determining the number of accelerometers, the final measurement parameters corresponding to each accelerometer, the expected installation position, the measurement range and the measurement accuracy. According to the determined accelerometer combination, embed the accelerometer combination and the off-line data acquisition device in the model entity, and finally obtain a model for testing; the off-line data acquisition device is connected to each of the accelerometers and is used to collect and store the measurement results of the accelerometers.

8. The system according to claim 7, wherein The accelerometer combination in the model includes: An accelerometer disposed at the center of mass of the model, and / or Two identical uniaxial accelerometers respectively disposed on the left and right sides of the center of mass of the model, and / or Two identical uniaxial accelerometers respectively disposed on the upper and lower sides of the center of mass of the model, which are used to measure and calculate the acceleration in the axial direction of the model.

9. A method for measuring the push-pull characteristics of a multi-method model, wherein It is implemented by using the multi-method model drag characteristic measurement system according to any one of claims 1-8, and includes the following steps: Obtain the model parameters and the wind tunnel flow field parameters, and estimate the displacement range of the model within the effective test time according to the model parameters and the wind tunnel flow field parameters; Suspend the model to be measured in the pulse wind tunnel in a preset posture through a suspension device; Based on the estimated displacement range of the model within the effective test time, adjust the positional relationship between the stop device and the model; Based on the estimated displacement range of the model within the effective test time, fine-tune the distance between the optical displacement measurement module and the tail of the model through an adjustment mechanism; Start the pulse wind tunnel, and obtain the measurement results of each accelerometer in the accelerometer combination and the optical displacement measurement module within the effective test time; Based on the measurement results of each accelerometer obtained, calculate the aerodynamic load in the drag direction of the model in the pulse wind tunnel flow field; Based on the measurement results of the optical displacement measurement module, verify the calculated aerodynamic load.

10. The measurement method according to claim 9, wherein The step of suspending the model to be measured in the pulse wind tunnel in a preset posture through a suspension device includes: Adjust the axis of the frame to be horizontal; Adjust the axis of the model to be horizontal and fix the model through a temporary support device; Add an installation reference block outside the front end face of the safety support rod, insert the safety support rod into the cavity at the tail of the model, and initially adjust the coaxiality of the safety support rod and the model; Connect a set of suspension wires of the suspension device from the frame perpendicular to the axis of the model to the position with the least flow field interference at the head of the model, and connect the other set of suspension wires from the frame perpendicular to the axis of the model to the end face of the tail of the model, and lift the model; Remove the temporary support device; Adjust the posture of the model to the preset posture by changing the posture of the frame and correspondingly adjust the posture of the safety support rod; Keep the suspended state and move the model forward, remove the installation reference block, and then put the model back.

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