Full scale reynolds number rigid cylinder self-excited vibration hybrid virtual experiment device

Abstract

The application provides a full-scale Reynolds number rigid cylinder self-excited vibration mixed virtual experiment device, which comprises a physical experiment system, a numerical control system and a motion transmission function solving module; the physical experiment system comprises an actuator module, a sliding frame module and a rigid cylinder test module; the actuator module is connected with the sliding frame module and drives the sliding frame module to move; the rigid cylinder test module is fixedly connected with the sliding frame module; the numerical control system comprises a host computer and the motion transmission function solving module; the host computer collects water dynamic load collected by the rigid cylinder test module in real time; the water dynamic load is converted into dynamic motion response of a rigid cylinder elastic system in real time through the motion transmission function solving module, and a rigid cylinder real-time motion response instruction is generated; and the actuator module responds to the real-time motion response instruction in real time. The application combines a numerical method and a physical model experiment method, realizes artificial adjustment of quality, stiffness and damping parameters of a rigid cylinder self-excited vibration experiment system under a full-scale Reynolds number, greatly accelerates experiment progress and saves experiment time.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, specifically to a hybrid virtual experimental device for the self-excited vibration of a rigid cylinder with a real-scale Reynolds number. Background Technology

[0002] Marine risers are typical slender cylindrical structures. Under the influence of ocean currents, these structures experience significant vortex-induced vibration, which is a major cause of structural fatigue damage in such structures.

[0003] To reveal the characteristics of vortex-induced vibration in slender cylinders, current research primarily relies on mechanistic model experiments. Despite extensive experimental studies on the self-excited oscillation of rigid cylinders in industry and academia, the dynamic behavior of vortex-induced vibration in rigid cylinders at ultra-high real-scale Reynolds numbers remains unclear. A review of existing literature reveals that current research on vortex-induced vibration of rigid cylinders is largely limited to the low Reynolds number (Re ~ 10⁴) range. A paper titled "Motions, Forces and Mode Transitions in Vortex-induced Vibrations at Low Mass-damping," published in the 13th issue of the *Journal of Fluids and Structures* in 1999, presents an experimental study on the vortex-induced vibration of a cylinder. The experimental setup and method described in the paper employ a single three-component force sensor, one end connected to an air bearing flange, and the other end fixedly connected to a rigid cylindrical model. The model has a diameter of 5.08 cm and a length of 43.18 cm. In order to adjust the reduced velocity range during the experiment, the flow rate had to be changed, which caused the Reynolds number to change as well.

[0004] Analysis revealed the following shortcomings of the experimental setup and methods: (1) In traditional cantilever experimental setups, the sensor is subjected to bending moment during measurement, which greatly affects the experimental accuracy in high Reynolds number rigid cylinder experiments; (2) Traditional self-excited oscillation experiments can only passively accept the actual mass of the real physical model, as well as the stiffness of the boundary using physical springs and the damping of the overall system. Replacing the rigid cylinder, springs, and reducing or increasing the system damping will consume a lot of time and affect the experimental progress; (3) During the experiment, since it is impossible to replace physical components such as springs, the reduction velocity adjustment method can only be carried out by changing the flow rate, which makes it impossible to conduct a series of parameter experiments at a constant Reynolds number; (4) Due to the size limitation of the experimental setup, the model pipe diameter is small, resulting in a large scale effect; (5) The actual mass of the real large mass is much larger than that of the rigid cylinder in the actual physical model, which will lead to extremely high requirements for the strength and stiffness of the experimental setup. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a hybrid virtual experimental device for the self-excited vibration of a rigid cylinder with a real-scale Reynolds number.

[0006] A hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number according to the present invention includes: a numerical control system and a physical experimental system;

[0007] The physical experiment system includes an actuator module, a carriage module, and a rigid cylinder testing module. The actuator module is connected to the carriage module and drives the carriage module to move. The rigid cylinder testing module is fixedly connected to the carriage module. The numerical control system includes a host computer and a motion transfer function (JTFC) calculation module. The host computer collects the hydrodynamic loads collected by the rigid cylinder testing module in real time. The JTFC calculation module converts the hydrodynamic loads into the dynamic motion response of the rigid cylinder elastic system in real time and generates a real-time motion response command for the rigid cylinder. The actuator module responds in real time according to the real-time motion response command for the rigid cylinder.

[0008] Preferably, the numerical control system further includes a motion controller and a servo driver;

[0009] The host computer acquires the input virtual mass, boundary virtual stiffness, and system damping parameters of the rigid cylinder. The motion controller sends the real-time motion response command of the rigid cylinder to the servo driver, and the servo driver controls the actuator module to generate a response.

[0010] Preferably, the motion transfer function calculation module calculates the motion transfer function based on the hydrodynamic load F(t) measured at time i. i ) and the Duhamel integral coefficient A(t) at time i. i ) and B(t i Solve for the motion command X(t) at time i+1. i+1 ) and Duhamel integral coefficient A(t) i+1 ) and B(t i+1 ):

[0011]

[0012]

[0013] X(t i+1 )=A(t i+1 sinω D t i+1 -B(t i+1 cosω D (t i+1 )

[0014] in,

[0015]

[0016] m, c, and k represent the virtual mass of the rigid cylinder, the system damping coefficient, and the boundary elastic stiffness, respectively, set by the user on the host computer; m a dt represents the actual mass of the virtual rigid cylinder physical model; dt represents the time step for refreshing motion commands from the motion controller.

[0017] Preferably, the top fixing structure module includes a frame structure workpiece, a long strip positioning flange plate, a linear track, and a first slider. Multiple long strip positioning flange plates are arranged in parallel on the frame structure workpiece. The linear track is fixedly arranged on the long strip positioning flange plate. Multiple first sliders are arranged on each linear track. The carriage module is fixedly connected to the first sliders.

[0018] Preferably, the actuator module includes a servo motor, a reducer, a motor adapter flange, and a linear module. The drive end of the servo motor is connected to the motor adapter flange through the reducer. The motor adapter flange is connected to the linear module to drive the linear module to move. The linear module is fixedly connected to the carriage module. The servo driver is electrically connected to the servo motor.

[0019] Preferably, the rigid cylindrical module includes a test module comprising an end truss structure, a third flange plate, an upper baffle plate, a rigid cylindrical module, a lower baffle plate, and a fourth flange;

[0020] One end of the end truss structure is fixedly connected to the carriage module, and the other end of the end truss structure is fixedly connected to the third flange plate. The upper baffle is fixedly installed on the third flange plate. One end of the rigid cylindrical module is fixedly installed on the third flange plate, and the other end of the rigid cylindrical module is fixedly connected to the lower baffle plate and the fourth flange.

[0021] Preferably, the rigid cylindrical module includes a hydrodynamic cylindrical pipe, a foam cylindrical pipe, an inner support square pipe, a first limiting member, a first end hinged flange plate, a first three-part force sensor, a first inner fixing member, a first outer clamping flange plate, a second outer clamping flange plate, a second inner fixing workpiece, a second three-part force sensor, a second end hinged flange plate, and a second limiting member;

[0022] The first limiting member is installed on the first end hinged flange plate. The first inner fixing member passes through the first end hinged flange plate and is connected to the third flange plate. The other end of the first inner fixing member is fixedly connected to the first outer clamping flange plate and one end of the inner support square tube, respectively. The other end of the inner support square tube is fixedly connected to the second outer flange plate and the second inner fixing workpiece. The second inner fixing workpiece passes through the second end hinged flange plate and is fixedly connected to the lower baffle plate and the fourth flange. The second limiting member is installed on the second end hinged flange plate. The first three-part force sensor is disposed between the first end hinged flange plate and the first inner fixing member. The second three-part force sensor is disposed between the second inner fixing workpiece and the second end hinged flange plate.

[0023] The foam tube is sleeved on the surface of the inner support square tube, and the hydrodynamic tube is sleeved on the surface of the foam tube.

[0024] Preferably, the edges of the first end hinged flange and the second end hinged flange are semi-circular, and the first end hinged flange and the second end hinged flange are in line contact with the inner wall of the hydrodynamic circular pipe.

[0025] Preferably, one end of the first internal fixing member and the second internal fixing member is square and is embedded in the inner wall of the inner support square tube. The other end of the first internal fixing member and the second internal fixing member is provided with four L-shaped bosses. The four L-shaped bosses form a square groove. The first three-part force sensor and the second three-part separation sensor are disposed in the square groove. The four L-shaped bosses penetrate the L-shaped through holes opened on the first end hinge flange plate and the second end hinge flange plate.

[0026] Preferably, the foam tube is made of EPS foam material, and the outer diameter of the foam tube is 2-5 mm smaller than the inner diameter of the hydrodynamic tube.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The experimental apparatus disclosed in this invention combines the advantages of numerical solution algorithms and physical model experiments, virtually simulating the mass, boundary stiffness, damping, and other parameters of a rigid cylinder. This reduces the mass of the actual physical model, accelerates the experimental progress, and enables a series of experiments at constant Reynolds numbers, achieving extreme parameter conditions that traditional physical model experiments cannot simulate. The rigid cylinder measurement module used in the physical system avoids problems such as sensor damage at ultra-high Reynolds numbers, severe interference from the free liquid surface, and large model mass.

[0029] 2. This invention can avoid the huge bending moment generated by the real-scale riser on the three-part force sensor at ultra-high Reynolds numbers, effectively ensuring the accuracy of hydrodynamic load measurement in physical model experiments.

[0030] 3. This invention employs a hybrid approach combining numerical methods and physical model experimental methods, enabling manual adjustment of the mass, stiffness, and damping parameters of the self-excited vibration experimental system of a rigid cylinder. This significantly accelerates the experimental progress and saves experimental time.

[0031] 4. This experimental setup can virtualize the parameters of a self-excited vibration experimental system for a rigid cylinder, enabling a relatively light real rigid cylinder to have structural properties with a large mass-to-weight ratio, thus reducing the strength and stiffness requirements of the experimental setup.

[0032] 5. The experimental setup allows for convenient modification of the system stiffness parameters, enabling the adjustment of the reduced velocity without altering the flow rate, thus ensuring that the experiment can be conducted under the reduced velocity conditions at a constant Reynolds number.

[0033] 6. The rigid cylinder experiment of this invention can use a large-diameter pipe with actual dimensions, avoiding the scale effect of the traditional small-diameter pipe model.

[0034] 7. The experimental apparatus has a simple overall structure, is easy to install, and is easy to implement. Attached Figure Description

[0035] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0036] Figure 1 This is an overall isometric perspective view of the device of the present invention;

[0037] Figure 2 This is a schematic diagram of the numerical control system of the present invention;

[0038] Figure 3 This is an isometric perspective view of the physical experiment system of the present invention;

[0039] Figure 4 This is a schematic diagram of the actuator module of the present invention;

[0040] Figure 5 These are the isometric and exploded views of the top fixing structure module of the present invention;

[0041] Figure 6 This is an isometric view of the carriage module of the present invention;

[0042] Figure 7 This is an exploded view of the rigid cylinder testing module of the present invention.

[0043] Figure 8 This is an isometric perspective view of the end truss structure of the present invention;

[0044] Figure 9 This is an exploded isometric view of the rigid cylindrical module of the present invention.

[0045] Figure 10 This is an isometric perspective view of the first and second internal fixation components of the present invention.

[0046] Figure 11 This is an isometric perspective view of the first and second end hinged flange plates of the present invention. Explanation of reference numerals:

[0047] Numerical System 1 End Truss Structure 24

[0048] Physical System 2 Third Flange Plate 25

[0049] Upper computer 3, upper baffle 26

[0050] Motion transfer function calculation module 4 Rigid cylinder module 27

[0051] Motion controller 5 Lower baffle 28

[0052] Servo driver 6, fourth flange plate 29

[0053] Actuator Module 7 Fifth Flange Plate 30

[0054] Top fixed structure module 8, end steel structure 31

[0055] Carriage module 9, sixth flange plate 32

[0056] Rigid cylinder test module 10 First limiting component 33

[0057] Linear module 11 First end hinged flange 34

[0058] Second slider 12 First force sensor 35

[0059] Motor adapter flange 13 First inner fastener 36

[0060] Reducer 14 First outer clamping flange 37

[0061] Servo motor 15, internal support square tube 38

[0062] Frame structure workpiece 16, second outer clamping flange plate 39

[0063] Long strip positioning flange plate 17 Second internal fastener 40

[0064] Linear track 18 Second force sensor 41

[0065] First slider 19, second end hinged flange 42

[0066] Main steel structure 20, Second limiting component 43

[0067] First flange plate 21, foam round tube 44

[0068] Second flange plate 22, hydrodynamic round pipe 45

[0069] Elbow flange plate 23 Detailed Implementation

[0070] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0071] This invention discloses a hybrid virtual experimental device for the self-excited vibration of a rigid cylinder with ultra-high Reynolds number, referring to... Figure 1 As shown, the device consists of a numerical control system 1 and a physical experiment system 2. The parameters of the numerical control system 1 are easily modified and traversed, while the external load measurement in the physical experiment system 2 is accurate. This allows the rigid cylinder and its elastic boundary in the physical experiment system 2 to be virtualized. The physical experiment system 2 measures the current hydrodynamic forces, the numerical control system 1 calculates the next motion response in real time, and the physical experiment system 2 executes the high-speed cyclic operation, achieving an equivalent simulation of the virtually set mass, boundary stiffness, and damping parameters of the rigid cylinder.

[0072] Reference Figure 2 As shown, the numerical control system 1 includes a host computer 3, a motion transfer function (JTFC) solving module 4, a motion controller 5, and a servo driver 6. The JTFC solving module 4 writes data to the motion controller 5 and connects to the host computer 3. The experimenter inputs the virtual mass, boundary virtual stiffness, and system damping of the rigid cylinder into the host computer 3. The host computer 3 collects the hydrodynamic loads acting on the rigid cylinder in real time and converts these loads into the dynamic motion response of the rigid cylinder's elastic system in real time through the JTFC solving module 4. The motion controller 5 then sends the real-time motion response commands of the rigid cylinder to the servo driver 6.

[0073] The motion transfer function solution module 4 uses the Duhamel recursive integral response solution method as its core. This solution module is based on the hydrodynamic load F(t) measured at time i. i ) and the Duhamel integral coefficient A(t) at time i. i ) and B(t i Solve for the motion command X(t) at time i+1. i+1 ) and Duhamel integral coefficient A(t) i+1 ) and B(t i+1 ):

[0074]

[0075]

[0076] X(t i+1 )=A(t i+1 sinω D t i+1 -B(t i+1 cosω D (t i+1 )

[0077] in,

[0078]

[0079] m, c, and k represent the virtual mass of the rigid cylinder, the system damping coefficient, and the boundary elastic stiffness, respectively, set by the user on the host computer; m a dt represents the actual mass of the virtual rigid cylinder physical model; dt represents the time step for refreshing motion commands from the motion controller.

[0080] Reference Figure 3 As shown, the physics experiment system 2 includes an actuator module 7, a top fixed structure module 8, a carriage module 9, and a rigid cylindrical test module 10. The actuator module 7 is connected to the carriage module 9 and drives the carriage module 9 to move. The rigid cylindrical test module 10 is fixedly connected to the carriage module 9. The physics experiment system 2 is installed under a marine engineering pool trailer. The movement of the trailer causes the rigid cylinder to form a relative flow field in the water. The actuator module 7 is fixed to the top fixed structure module 8, driving the carriage module 9 and the rigidly connected rigid cylindrical test module 10 to complete the actuation command.

[0081] Reference Figure 4 As shown, the actuator module 7 includes a servo motor 15, a reducer 14, a motor adapter flange 13, and a linear module 11. The drive end of the servo motor 15 is connected to the motor adapter flange 13 via the reducer 14. The motor adapter flange 13 is connected to the linear module 11, driving the linear module 11 to move. The linear module 11 is bolted to the track flange platform of the top fixed structure module 8. The servo motor 15, according to the motion response command issued by the servo driver 6, drives the linear module to move via the reducer 14.

[0082] Reference Figure 5As shown, the top fixed structure module 8 includes a frame structure workpiece 16, elongated positioning flange plates 17, linear tracks 18, and first sliders 19. The frame structure workpiece 16 is welded from high-strength steel into a rectangular frame structure, with a track flange platform welded inside. Four elongated positioning flange plates 17 are welded onto the frame structure workpiece 16 and then precisely cut into stepped interfaces using a gantry milling machine. The four linear tracks 18 are made of stainless steel and are bolted to the middle of the stepped interfaces of the four elongated positioning flange plates 17 to ensure high-precision parallelism of the four linear tracks 18. Each linear track 18 is equipped with two first sliders 19.

[0083] Reference Figure 6 As shown, the carriage module 9 comprises a main steel structure 20, a first flange plate 21, a second flange plate 22, and an elbow flange plate 23. The main steel structure 20 is made of high-strength rectangular steel. The second flange plate 22 is bolted to the second slider 12 of the linear module 11 in the middle of the main steel structure 20. Four first flange plates 21 are welded around the main steel structure 20 according to the position of the first slider 19 on the linear track 18. The carriage module 9 frame is mounted on the top fixed structure module 8, with one end extending outward in a cantilever shape and reinforced by the elbow flange plate 23. The elbow flange plate 23 is welded to the main steel structure 20 and connected to the top fifth flange plate 30 of the rigid cylindrical test module 10.

[0084] Reference Figure 7 As shown, the rigid cylindrical module 27 includes a test module comprising an end truss structure 24, a third flange plate 25, an upper baffle plate 26, a rigid cylindrical module 27, a lower baffle plate 28, and a fourth flange 29. One end of the end truss structure 24 is fixedly connected to the carriage module 9 by bolts, and the other end of the end truss structure 24 is fixedly connected to the third flange plate 25 by bolts. The upper baffle plate 26 is fixedly installed on the third flange plate 25. One end of the rigid cylindrical module 27 is fixedly installed on the third flange plate 25, and the other end of the rigid cylindrical module 27 is fixedly connected to the lower baffle plate 28 and the fourth flange 29. Bolts pass through the fourth flange plate 29 and the lower baffle plate 28 and are tightened onto the rigid cylindrical module 27, thereby clamping and fixing the lower baffle plate 28 to the end of the rigid cylindrical module 27 by the fourth flange plate 29.

[0085] like Figure 8 As shown, the end truss structure 24 includes a fifth flange plate 30, an end steel structure 31, and a sixth flange plate 32. The fifth flange plate 30 is bolted to the elbow flange and welded to the end steel structure 31. The sixth flange plate 32 is bolted to the third flange plate 25 and is also welded to the end steel structure.

[0086] Reference Figure 9 As shown, the rigid cylindrical module 27 includes a hydrodynamic cylindrical pipe 45, a foam cylindrical pipe 44, an inner support square pipe 38, a first limiting member 33, a first end hinged flange plate 34, a first three-part force sensor 35, a first inner fixing member 36, a first outer clamping flange plate 37, a second outer clamping flange plate 39, a second inner fixing workpiece, a second three-part force sensor 41, a second end hinged flange plate 42, and a second limiting member 43.

[0087] There are three first limiting members 33, which are installed at three quarter-quadrant positions of the first end hinged flange plate 34. The first inner fixing member 36 passes through the first end hinged flange plate 34 and connects to the third flange plate 25. The other end of the first inner fixing member 36 is fixedly connected to one end of the first outer clamping flange plate 37 and the inner support square tube 38, respectively. Bolts pass through the four first outer clamping flange plates 37 and the inner support square tube 38 and are tightened onto the first inner fixing member 36, thereby firmly connecting the inner support square tube 38 and the first inner fixing member 36 together. The other end of the inner support square tube 38 is fixedly connected to the second outer flange plate and the second inner fixed workpiece. The second inner fixed workpiece passes through the second end hinged flange plate 42 and is fixedly connected to the lower baffle plate 28 and the fourth flange 29. The second limiting member 43 is installed at three 1 / 4 quadrants of the second end hinged flange plate 42, and together with the first limiting member 33, restricts the movement of the hydrodynamic circular pipe 45 along its length axial direction. The first three-part force sensor 35 is disposed between the first end hinged flange plate 34 and the first inner fixed member 36. The first end hinged flange plate 34 is fixedly connected to one end of the first three-part force sensor 35 by bolts, and the other end of the first three-part force sensor 35 is fixed to the first inner fixed member 36 by bolts. The second three-part force sensor 41 is disposed between the second inner fixed workpiece 36 and the second end hinged flange plate 42. The second three-part force sensor 41 is installed on the second inner fixed member 40 by bolts at one end and on the second end hinged flange plate 42 at the other end.

[0088] The foam tube 44 is tightly fitted and wrapped around the surface of the inner supporting square tube 38, and the hydrodynamic tube 45 is sleeved on the surface of the foam tube 44. The edges of the first end hinged flange plate 34 and the second end hinged flange plate 42 are semi-circular, and the first end hinged flange plate 34 and the second end hinged flange plate 42 are in line contact with the inner wall of the hydrodynamic tube 45. The hydrodynamic tube 45 is made of lightweight carbon fiber material, which reduces the weight of the rigid cylindrical module 27 and lowers the strength requirements of the overall experimental device. The foam tube is made of lightweight EPS foam, and its size is about 2-5 mm smaller than the inner wall size of the hydrodynamic tube 45, so as to drain the fluid inside the hydrodynamic tube 45 during the experiment and reduce the influence on the measurement of the hydrodynamic load.

[0089] Reference Figure 10As shown, the first internal fixing component 36 and the second internal fixing component 40 are both made of aluminum alloy. The first internal fixing component is made of high-strength stainless steel and the second internal fixing component 40 is made of aluminum alloy. One end of each internal fixing component is square and has the same dimensions as the inner wall of the inner support square tube 38. The other end is machined with four L-shaped bosses, forming a square groove in the center. The force sensor is installed in the groove. The L-shaped bosses protrude through the L-shaped through holes of the end flange plate.

[0090] like Figure 11 As shown, the first end hinged flange plate 34 and the second end hinged flange plate 42 are made of high-strength aluminum alloy. The edge of the flange plate is semi-circular to ensure that it is in line contact with the inner wall of the hydrodynamic pipe 45 when supporting it, thereby releasing the bending moment acting on the first three-part force sensor 35 and the second three-part force sensor 41 during the experiment, and playing a role similar to the hinged boundary. The first end flange plate and the second end flange plate have L-shaped through holes to allow the first inner fixing member 36 and the second inner fixing member 40 to pass through during installation without contacting the two flange plates. A strip-shaped slit is opened at the 1 / 4 quadrant of the flange plate for the routing of the signal output lines of the three-part force sensors.

[0091] The installation and implementation process of this experimental setup is as follows:

[0092] Before the formal experimental testing, based on the actual experimental needs, the diameter of the rigid cylinder, the specific conditions of the test flow rate, the size of the laboratory drag pool, and the economic efficiency of the experimental setup, the various components of the experimental apparatus were designed. After all experimental components were fabricated, the detailed installation steps are as follows:

[0093] First, the top fixed structure module 8 is welded according to the description of this invention, and the linear track 18 and the first slider 19 are assembled. The carriage module 9 is installed on the top fixed structure module 8, and the assembled device is installed on the marine engineering towing tank. Next, the actuator module 7 is installed, and the linear module 11 is fixed to the flange platform in the middle of the top fixed structure module 8 by pressure blocks. The servo motor 15, the reducer 14, and the reducer 14 flange are sequentially connected to the linear module 11, and the second flange plate 22 is installed with the second slider 12.

[0094] Next, assemble the rigid cylindrical module 27, fixing the first internal fixing member 36 and the second internal fixing workpiece to both ends of the inner support square tube 38 via the first external clamping flange plate 37 and the second external clamping flange plate 39, respectively. Then, install the first three-part force sensor 35 and the second three-part force sensor 41 on the first internal fixing member 36 and the second internal fixing workpiece, respectively. Next, install the first limiter on the first end hinge plate and tighten it with bolts to the first three-part force sensor 35. Tightly fit the foam tube onto the inner support square tube 38, and then push the hydrodynamic round tube 45 from the bottom onto the first end hinge flange plate 34 and make it contact the first limiter 33. Install the second end hinge flange plate 42 onto the second three-part force sensor 41, and install the second limiter to prevent the hydrodynamic round tube 45 from moving axially. Further, use high-strength stainless steel profiles for welding, and bolt the third flange plate 25 to the fifth flange plate 30 of the end truss structure 24. The rigid cylindrical model is fixed to the third flange plate 25 with bolts. The upper baffle plate 26 is also fixed to the third flange plate 25 with bolts. The rigid cylindrical module 27 is also fixed to the third flange plate 25 with bolts. Bolts pass through the fourth flange plate 29 and the lower baffle plate 28 and are tightened onto the rigid cylindrical module 27, thereby clamping and fixing the lower baffle plate 28 to the end of the rigid cylindrical module 27 by the fourth flange plate 29.

[0095] Finally, the feedback signals from the first three-part force sensor 35, the second three-part force sensor 41, and the servo motor 15 are connected to the numerical system. The host computer 3, motion controller 5, and driver are connected for communication, and the motion transfer function calculation module 4 is written into the controller. The experimenter inputs the virtual mass of the rigid cylinder, the boundary virtual spring stiffness, and the system damping parameters through the host computer 3, starts the trailer at the set flow rate, and starts the virtual hybrid experimental system to conduct self-excited vibration experiments of the rigid cylinder at different Reynolds numbers. After the experiment, the displacement motion response and load information of the self-excited oscillation of the rigid cylinder are collected and saved synchronously. In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0096] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A hybrid virtual experimental device for the self-excited vibration of a rigid cylinder with a real-scale Reynolds number, characterized in that, include: Numerical control systems and physical experimental systems; The physical experiment system includes an actuator module, a carriage module, and a rigid cylinder testing module. The actuator module is connected to the carriage module and drives the carriage module to move. The rigid cylinder testing module is fixedly connected to the carriage module. The numerical control system includes a host computer and a motion transfer function calculation module. The host computer collects the hydrodynamic load collected by the rigid cylinder testing module in real time, and converts the hydrodynamic load into the dynamic motion response of the rigid cylinder elastic system in real time through the motion transfer function calculation module, and generates a real-time motion response command for the rigid cylinder. The actuator module responds in real time according to the real-time motion response command for the rigid cylinder. The motion transfer function calculation module calculates the hydrodynamic load measured at time i. F ( t i and the Duhamel integral coefficient at time i. A ( t i )and B ( t i Solve for the motion command at time i+1. X ( t i+1 ) and Duhamel integral coefficient A ( t i+1 )and B ( t i+1 ): in, m, c, k These are the virtual mass of the rigid cylinder set by the user on the host computer, the system damping coefficient, and the boundary elastic stiffness, respectively. m a The actual mass of the virtual rigid cylinder physical model; dt The time step for refreshing motion commands for the motion controller.

2. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 1, characterized in that, The numerical control system also includes a motion controller and a servo driver; The host computer acquires the input virtual mass, boundary virtual stiffness, and system damping parameters of the rigid cylinder. The motion controller sends the real-time motion response command of the rigid cylinder to the servo driver, and the servo driver controls the actuator module to generate a response.

3. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 1, characterized in that, It also includes a top fixing structure module; the top fixing structure module includes a frame structure workpiece, a long strip positioning flange plate, a linear track and a first slider, multiple long strip positioning flange plates are arranged in parallel on the frame structure workpiece, the linear track is fixedly arranged on the long strip positioning flange plate, and multiple first sliders are arranged on each linear track, and the carriage module is fixedly connected to the first slider.

4. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 2, characterized in that, The actuator module includes a servo motor, a reducer, a motor adapter flange, and a linear module. The drive end of the servo motor is connected to the motor adapter flange through the reducer. The motor adapter flange is connected to the linear module to drive the linear module to move. The linear module is fixedly connected to the carriage module. The servo driver is electrically connected to the servo motor.

5. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 1, characterized in that, It also includes a rigid cylindrical module; the rigid cylindrical module includes a test module comprising an end truss structure, a third flange plate, an upper baffle plate, a rigid cylindrical module, a lower baffle plate, and a fourth flange; One end of the end truss structure is fixedly connected to the carriage module, and the other end of the end truss structure is fixedly connected to the third flange plate. The upper baffle is fixedly installed on the third flange plate. One end of the rigid cylindrical module is fixedly installed on the third flange plate, and the other end of the rigid cylindrical module is fixedly connected to the lower baffle plate and the fourth flange.

6. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 5, characterized in that, The rigid cylindrical module includes a hydrodynamic cylindrical pipe, a foam cylindrical pipe, an inner support square pipe, a first limiting member, a first end hinged flange plate, a first three-part force sensor, a first inner fixing member, a first outer clamping flange plate, a second outer clamping flange plate, a second inner fixing workpiece, a second three-part force sensor, a second end hinged flange plate, and a second limiting member. The first limiting member is installed on the first end hinged flange plate. The first inner fixing member passes through the first end hinged flange plate and is connected to the third flange plate. The other end of the first inner fixing member is fixedly connected to the first outer clamping flange plate and one end of the inner support square tube, respectively. The other end of the inner support square tube is fixedly connected to the second outer flange plate and the second inner fixing workpiece. The second inner fixing workpiece passes through the second end hinged flange plate and is fixedly connected to the lower baffle plate and the fourth flange. The second limiting member is installed on the second end hinged flange plate. The first three-part force sensor is disposed between the first end hinged flange plate and the first inner fixing member. The second three-part force sensor is disposed between the second inner fixing workpiece and the second end hinged flange plate. The foam tube is sleeved on the surface of the inner support square tube, and the hydrodynamic tube is sleeved on the surface of the foam tube.

7. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 6, characterized in that, The edges of the first end hinged flange and the second end hinged flange are semi-circular, and the first end hinged flange and the second end hinged flange are in line contact with the inner wall of the hydrodynamic circular pipe.

8. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 6, characterized in that, One end of the first internal fixation member and the second internal fixation member is square and is embedded in the inner wall of the inner support square tube. The other end of the first internal fixation member and the second internal fixation member is provided with four L-shaped bosses. The four L-shaped bosses form a square groove. The first three-part force sensor and the second three-part force sensor are disposed in the square groove. The four L-shaped bosses penetrate the L-shaped through holes opened on the first end hinge flange plate and the second end hinge flange plate.

9. The hybrid virtual experimental device for self-excited vibration of a rigid cylinder with real-scale Reynolds number as described in claim 6, characterized in that, The foam tube is made of EPS foam material, and the outer diameter of the foam tube is 2-5mm smaller than the inner diameter of the hydrodynamic tube.

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