Modularized rotating water tank typhoon simulation system based on similarity law and experiment method

Abstract

The invention provides a modular rotating water tank typhoon simulation system based on a similarity law, and the system comprises a basic rotating platform, a driving assembly of which drives a horizontal platform surface provided with a transparent water tank to rotate, so as to provide a Coriolis force background field; an inclined bottom plate with an adjustable inclination angle and a three-dimensional terrain model fixed on the inclined bottom plate are used for simulating a terrain effect; the vortex generation module is mounted through a detachable interface, comprises a stirring type vortex generation module, a suction type vortex generation module and a double-vortex generation module, and is used for generating controllable cyclone type vortexes; and the data acquisition control module is used for system control and experimental data recording. A controllable Coriolis force background field is provided through the basic rotating platform, and a reliable hardware basis is provided for application of the dynamic similarity law through physical cooperation of the terrain simulation module and the replaceable vortex generation module, so that a parameter design process based on the theoretical similarity law can be accurately executed in an entity system, and the design efficiency is improved. Therefore, the experiment can consider both simulation precision and operation efficiency.

Description

Technical Field

[0001] This invention relates to the field of typhoon simulation experiment technology, and in particular to a modular rotating water tank typhoon simulation system and experimental method based on the similarity law. Background Technology

[0002] Accurate prediction of tropical cyclone (TC) tracks is crucial for disaster prevention and mitigation. However, when typhoon tracks involve complex terrain (such as the Central Mountain Range, CMR, over Taiwan), their speed, track deflection, track continuity / discontinuity, and vortex structure often undergo complex changes. This makes track prediction highly uncertain, potentially leading to biased or delayed warnings and increasing the risk of disasters such as torrential rain, strong winds, and flash floods.

[0003] In the Northwest Pacific region of Taiwan, the complex topography, primarily influenced by CMR (Constant Motion Regulator), often leads to significant deflections in typhoon paths. Based on over a century of typhoon records in Taiwan (1897–2021), researchers have categorized typhoon landfall paths into eight types. The most prevalent path types affecting Taiwan include those making landfall in the north, central, and south. These path deflections are influenced by various factors, including the typhoon's intensity, size, and environmental steering currents, reflecting the complex interaction between the typhoon's internal structure and surrounding environmental conditions. Furthermore, in cases of binary typhoons, such as Sarika and Haima in 2016, the Fujiwhara effect further complicates path interactions, potentially leading to enhanced deflection or merging.

[0004] Historical observations and simulations have revealed several mechanisms for typhoon path deflection, including: topographic blocking effects (mountains obstructing airflow, causing path deflection or deceleration), topographic channel effects (airflow accelerated and guided by valleys, altering typhoon trajectory), topographic beta effects (similar to planetary beta effects, causing vortices to shift northwestward on mountain slopes), and changes in typhoon circulation structure. These mechanisms have been confirmed and explained in the literature through observations, numerical simulations, and idealized experiments. In general, complex terrain significantly impacts typhoon paths, and the limited availability of historical typhoon observation data makes simulating typhoon path deflection through complex terrain one of the most challenging aspects of current research.

[0005] To study such phenomena, existing technologies mainly rely on two approaches: numerical simulation and laboratory physical simulation, but both have significant limitations:

[0006] Lack of systematic similarity law guidance: Many traditional laboratory experiments simulate typhoon vortices and terrain in a relatively simple way, making it difficult to fully consider the effects of dynamic similarity laws (such as vortex Rossby number and terrain β parameter) and geometric similarity laws; this often leads to the experiment failing to accurately reproduce the degree of path deflection and flow characteristics when simulating real typhoons, especially under double vortex or run-of-river conditions.

[0007] The experimental parameter determination mechanism is inadequate: some existing experiments assume a constant vortex structure or treat the feedback of topographic effects as static, failing to dynamically adjust experimental parameters based on the real-time state of the prototype typhoon (such as intensity, scale, spacing, and glide velocity). In other words, the experiments lack a mechanism to systematically determine the rotation rate, topographic scale, and vortex generation method based on similar conditions.

[0008] Accuracy and efficiency are difficult to balance: While high-resolution comprehensive numerical weather prediction models can simulate the effects of complex terrain, they are computationally intensive and time-consuming, making it difficult to meet the needs of real-time research; while simplified laboratory experiments are quick to operate, they often sacrifice simulation accuracy and are less effective under complex terrain conditions. Summary of the Invention

[0009] This invention proposes a modular rotating water tank typhoon simulation system and experimental method based on similarity law, which solves the problems of existing typhoon simulation systems, such as lack of systematic similarity law guidance, imperfect experimental parameter determination mechanism, and difficulty in balancing accuracy and efficiency.

[0010] The technical solution of this invention is implemented as follows: The first aspect of this invention provides a modular rotating water tank typhoon simulation system based on the similarity law, comprising: A basic rotating platform includes a drive assembly, a platform surface, and a transparent water tank. The transparent water tank is fixedly installed on the platform surface, and the drive assembly is used to drive the platform surface to rotate about a vertical axis. The terrain simulation module includes an inclined base plate placed at the bottom of the water tank with an adjustable inclination angle, and a three-dimensional terrain model fixed on the inclined base plate; A vortex generation module is installed on a base rotating platform via a detachable interface and is used to generate cyclonic vortices in the fluid of a transparent water tank; the vortex generation module includes at least one of a stirring vortex generation module, a suction vortex generation module, and a dual vortex generation module. The data acquisition and control module is used to control the operating parameters of the basic rotating platform and the vortex generation module, and to collect and record the flow field visualization data during the experiment.

[0011] Specifically, the stirring vortex generation module includes: An inner cylinder and an outer cylinder are coaxially arranged, with the bottom of the outer cylinder open and the top of the outer cylinder equipped with a bearing that mates with the inner cylinder; A first drive motor that drives the inner cylinder to rotate about its axis;

[0012] A first lifting mechanism for driving the inner cylinder and outer cylinder to move vertically as a whole.

[0013] Specifically, the suction-type vortex generation module includes: The suction head has a conical nozzle at the bottom and an annular flow guide around the suction head. The suction tubing connected to the suction head; A suction pump installed on a suction pipeline; Water storage containers used to measure the amount of water extracted; A second lifting mechanism that drives the suction head to rise and fall.

[0014] Specifically, the dual-vortex generation module includes: Vertical guide rails mounted on the frame; A lifting plate is slidably mounted on a vertical guide rail, and a horizontal moving module is installed on the lifting plate; A third lifting mechanism, fixedly installed on the top of the frame, is used to drive the lifting platform to rise and fall; Two sets of vortex generating units are arranged side by side on a horizontally moving module. The horizontally moving module is used to adjust the center distance between the two sets of vortex generating units. Each set of vortex generating units includes an inner cylinder and an outer cylinder arranged coaxially. The bottom of the outer cylinder is open, and the top of the outer cylinder is provided with a bearing that cooperates with the inner cylinder. A belt drive system includes a driving pulley, a timing belt, and a driven pulley. The driving pulley and the driven pulley are respectively mounted on the tops of two inner cylinders, and the timing belt is sleeved on the driving pulley and the driven pulley. The second drive motor is used to drive the drive wheel to rotate. The drive wheel drives the driven wheel to rotate through the synchronous belt, thereby driving the two inner cylinders to rotate.

[0015] Preferably, the typhoon simulation system further includes a traffic flow simulation module, the traffic flow simulation module comprising: A support platform that slides on an inclined base plate is used to support a fixed terrain model; The traction mechanism connecting the support platform includes a traction rope, a guide pulley, a tension sensor, and a reel. The guide pulley is mounted on the top of the water tank via a first horizontal rotating base, and the reel is mounted on the bottom of the water tank via a second horizontal rotating base. The tension sensor is mounted in the middle of the traction rope. One end of the traction rope is connected to the support platform, and the other end passes around the guide pulley and is wound around the reel. A third drive motor drives the winding reel to wind or unwind, and the third drive motor is fixedly mounted on the second horizontal rotating base.

[0016] A second aspect of this invention provides a modular rotating water tank typhoon simulation experimental method based on the similarity law, comprising the following steps: Obtain key physical parameters of the target typhoon prototype, including the Coriolis parameter. Planetary β parameters Maximum wind speed Maximum wind speed radius Terrain features and height The terrain feature width 'a' and the equivalent depth of environmental fluids 'D'; Based on the principle of potential vorticity conservation, a set of core dimensionless parameters are calculated to characterize the dynamic similarity of the target typhoon prototype-typhoon simulation system. Based on the key physical parameters of the target typhoon prototype and the physical constraints of the experimental system, the basic parameters of the model are determined, including the rotational angular velocity. and base slope Maximum wind speed of the model vortex and the maximum radius of the model vortex ; Based on the core dimensionless parameters and preset similarity conditions, the model-derived physical parameters for each module in the typhoon simulation system are determined, including the model fluid depth. Model terrain width and model terrain height ; The typhoon simulation system is configured based on the basic parameters and derived physical parameters of the model. The basic rotating platform is started to the set angular velocity. After the fluid reaches solid rotation equilibrium, vortices are generated through the vortex generation module, and the experimental process of the interaction between the vortex and the terrain model is recorded using the data acquisition and control module.

[0017] Specifically, the core dimensionless parameters include at least the parameters calculated using the following formula: Planetary β parameters: ; Terrain β parameter: ; in, The slope of the terrain; Geometric scale ratio: ; The model fluid depth Based on similar conditions It is calculated using the following formula: ; The model terrain width Based on similar conditions It is calculated using the following formula: ; The model terrain height Based on similar conditions It is calculated using the following formula: ; In this context, the subscript p represents the target typhoon prototype, and the subscript m represents the typhoon simulation system.

[0018] Furthermore, when simulating the interaction of two typhoons: The key physical parameters of the target typhoon prototype also include the distance d between the centers of the two typhoons and the vortex characteristic parameters of the two typhoons. The core dimensionless parameter also includes the spacing parameter. and strength ratio parameter : ; ; In this context, the subscripts A and B represent Typhoon A and Typhoon B, which are two typhoons. The physical parameters derived from the model also include the model's double vortex spacing. According to similar conditions From the formula Calculated; By adjusting the horizontal movement module of the dual vortex generator module, the center distance between the two sets of vortex generator units is set to... Furthermore, by configuring the diameter ratio of the driving pulley to the driven pulley in the belt drive system, the rotational speed ratio of the two inner cylinders is adjusted. This generates a double vortex with the target intensity ratio.

[0019] Furthermore, the maximum wind speed of the model vortex in the basic parameters of the model... and the radius of maximum wind speed The type of vortex generator selected is determined by associating its operating parameters:

[0020] If a stirring vortex generation module is used, the operating parameters include the angular velocity of the inner cylindrical stirring. Duration of agitation ;

[0021] If a suction-type vortex generator module is used, the operating parameters include the suction flow rate. Duration of suction ,and Satisfying the approximation relation: ; in, These are the Coriolis parameters for the model.

[0022] Preferably, when the typhoon simulation system includes a glide flow simulation module, the method further includes a glide flow field simulation step: Obtain the environmental steering airflow velocity of the prototype typhoon And calculate dimensionless velocities. ; Based on the principle of relative motion, determine the drag speed corresponding to the model. And the dragging direction, wherein the dragging direction is set to be opposite to the direction of the guiding airflow of the environment to be simulated; During the experiment, once the vortex was generated and stabilized, the flow simulation module was simultaneously activated to control the third drive motor to drive the winding reel at a speed of The platform carrying the terrain model is pulled along a set direction and moved at a constant speed to simulate the modulation effect of environmental guiding airflow on the typhoon path, and the vortex motion trajectory under this combined condition is recorded by the data acquisition and control module.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention provides a controllable Coriolis force background field through an integrated basic rotating platform. Through the physical collaboration of the terrain simulation module and the replaceable vortex generation module, it provides a reliable hardware foundation and operation interface for the rigorous application of the dynamic similarity law. Through the data acquisition and control module, it realizes precise control and recording of the process, so that the parameter design process based on the theoretical similarity law can be accurately executed in the physical system, thereby ensuring that the experiment can take into account both simulation accuracy and operation efficiency. (2) The stirring vortex generation module of the present invention directly injects angular momentum into the fluid through the high-speed rotation of the coaxial inner column, and the outer cylinder constrains the vortex formation range, so that the experimenter can generate a cyclone vortex with clear boundaries and stable strength in a short time, which greatly shortens the single experiment cycle and improves the experimental efficiency. (3) The suction vortex generation module of the present invention simulates the mass sink process of low-level convergence of typhoons. The vortex generated in this way has better axisymmetry and smoother peripheral circulation. Its three-dimensional structure is closer to the baroclinic characteristics of real typhoons, making up for the shortcomings of pure mechanical stirring in simulating the fine structure of vortex. (4) The dual vortex generation module of the present invention achieves independent and precise control of the spacing and relative intensity of the two vortices through the design of horizontal slide rail and differential belt drive, enabling researchers to quantitatively set different dimensionless spacing and intensity ratios, thereby systematically reproducing the full spectrum of dynamic behavior of the two typhoons from weak interaction, binding and mutual rotation to final merger in the laboratory, providing a controllable experimental platform for revealing the physical mechanism of the Fujiwara effect and its impact on path change. (5) The current simulation module of the present invention uses a drag terrain model to simulate the environmental guidance airflow, without the need to arrange a complex flow-generating system at the boundary of the rotating water tank, thus avoiding the interference of inflow disturbance on the main experimental vortex; by controlling the drag speed and direction, the guiding effect of different environmental flow fields on the typhoon path can be simulated, realizing the effective coupling study of the complex three-dimensional interaction of "vortex-terrain-environmental flow" in a simple rotating system. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the basic rotating platform in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the stirring vortex generation module in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of the suction-type vortex generation module in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the structure of the dual vortex generation module in an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the flow simulation module in an embodiment of the present invention.

[0030] Figure 6 This is a flowchart of the modular rotating water tank typhoon simulation experimental method based on the similarity law of the present invention.

[0031] In the diagram: 1. Drive assembly; 2. Horizontal platform; 3. Transparent water tank; 4. Inclined base plate; 5. Terrain model; 6. Detachable interface; 7. Inner cylinder; 8. Outer cylinder; 9. Bearing; 10. First drive motor; 11. First lifting mechanism; 12. Conical suction nozzle; 13. Flow guide; 14. Suction pipeline; 15. Suction pump; 16. Water storage container; 17. Second lifting mechanism; 18. Frame; 19. Vertical guide rail; 20. Lifting plate; 21. Horizontal moving module; 22. Third lifting mechanism; 23. Drive wheel; 24. Synchronous belt; 25. Driven wheel; 26. Bearing platform; 27. Traction rope; 28. Guide pulley; 29. ​​Tension sensor; 30. Winding reel; 31. First horizontal rotating base; 32. Second horizontal rotating base; 33. Third drive motor. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Reference Figures 1 to 5 The first aspect of this invention provides a modular rotating water tank typhoon simulation system based on the similarity law, comprising:

[0034] Basic rotating platform, such as Figure 1 As shown, the system includes a drive assembly 1, a platform surface 2, and a transparent water tank 3 (in this embodiment, the transparent water tank 3 is a rectangular glass or acrylic water tank). The transparent water tank 3 is fixedly installed on the platform surface 2. The drive assembly 1 is used to drive the platform surface 2 to rotate around a vertical axis. The drive assembly 1 typically includes a variable frequency motor, a synchronous belt, or a gear transmission mechanism, which can achieve continuous adjustment of the rotational angular velocity within a set range, with a rotational speed stability better than ±0.5%. The system parameters of the basic rotating platform are shown in Table 1 below:

[0035] Table 1 System Parameters of the Basic Rotary Platform

[0036] The core principle of the basic rotating platform is to simulate the Earth's rotation effect by using the Coriolis force on the fluid in a rotating reference frame. When the tank rotates stably at an angular velocity Ω, any relative motion in the fluid will be subject to the Coriolis force, the magnitude of which is related to the equivalent Coriolis parameter. It is directly proportional. By adjusting the rotation speed, the geodynamic environment at different latitudes can be simulated. When the fluid reaches a state of rotational equilibrium with the solid, there is no relative motion inside it. At this point, introducing a disturbance can reveal a geostrophic flow phenomenon similar to that in the atmosphere.

[0037] Terrain simulation module, such as Figure 1 As shown, the system includes an adjustable inclined base plate 4 placed at the bottom of the water tank 3, and a three-dimensional terrain model 5 fixed on the inclined base plate 4. In this embodiment, the inclined base plate 4 is typically made of transparent acrylic sheet, with one end raised by an adjustable bracket to form an adjustable inclination angle. The three-dimensional terrain model is scaled according to the geometric similarity law based on the simulated target (such as the Central Mountain Range of Taiwan, China), and is usually an elliptical mountain. The terrain model is fixed to the base plate by magnetic attraction or snap-fit. The system parameters of the terrain simulation module are shown in Table 2 below.

[0038] Table 2 System Parameters of Terrain Simulation Module

[0039] The terrain simulation module simulates atmospheric dynamics effects through two mechanisms. First, the inclined base plate 4 generates a fluid depth gradient along the slope direction. As the fluid column moves along this gradient direction, a relative vorticity change occurs due to the conservation of potential vorticity; this effect is equivalent to the planetary beta effect in the atmosphere. Second, a three-dimensional terrain model 5 (such as an elliptical mountain) placed on the base plate 4 generates local depth variations, simulating the dynamic response of a typhoon approaching an island terrain, including the terrain beta effect, blocking effect, and channel effect. The combination of these two mechanisms can fully reproduce the core physical processes of the interaction between typhoons and complex terrain.

[0040] A vortex generation module is installed on a base rotating platform via a detachable interface 6 and is used to generate cyclonic vortices in the fluid in the transparent water tank 3; the vortex generation module includes at least one of a stirring vortex generation module, a suction vortex generation module, and a dual vortex generation module.

[0041] The data acquisition and control module is used to control the operating parameters of the basic rotating platform and the vortex generation module, and to collect and record the flow field visualization data during the experiment. This module typically includes a high-resolution camera (for stripe photography or PIV particle image velocimetry), a laser sheet light source, a rotation speed sensor, a tension sensor, and a central controller, which can synchronously control the actions of each module and record data such as vortex trajectory and velocity field.

[0042] Specifically, such as Figure 2 As shown, the stirring vortex generation module includes:

[0043] An inner cylinder 7 and an outer cylinder 8 are coaxially arranged. The bottom of the outer cylinder 8 is open, and the top of the outer cylinder 8 is provided with a bearing 9 that mates with the inner cylinder 7.

[0044] A first drive motor 10 drives the inner cylinder 7 to rotate about its axis;

[0045] The first lifting mechanism 11 (cylinder or electric push rod) is used to drive the inner cylinder 7 and the outer cylinder 8 to vertically rise and fall as a whole.

[0046] In this embodiment, the inner cylinder is a solid structure made of stainless steel or PVC; the outer cylinder is a thin-walled structure with an open bottom to allow fluid exchange. Both are coaxially mounted via precision bearings, and the inner cylinder is driven by a DC brushless motor. The system parameters of the stirring vortex generation module are shown in Table 3 below:

[0047] Table 3 System Parameters of the Stirring-Type Vortex Generation Module

[0048] The stirring-type vortex generation module directly injects angular momentum into the fluid through mechanical rotation. When a cylinder immersed in the rotating fluid rotates rapidly, the surrounding fluid is driven by viscosity to form a tangential velocity distribution. The concentric double-cylinder structure optimizes the radial structure of the vortex: the high-speed rotation of the inner cylinder generates core vortex, while the outer cylinder constrains the spatial range of the initial vortex, resulting in a more concentrated core and a more defined boundary. When the cylinder suddenly stops and is rapidly lifted off the water surface, the fluid, having acquired angular momentum, self-organizes into a stable cyclonic vortex under the influence of the Coriolis force.

[0049] Specifically, such as Figure 3 As shown, the suction-type vortex generation module includes:

[0050] The lower end is equipped with a suction head with a conical suction nozzle 12, and the suction head is surrounded by an annular guide shroud 13;

[0051] Suction tubing 14 (inner diameter 8-12 mm) connected to the suction head;

[0052] A suction pump 15 is installed on the suction pipeline 14;

[0053] Water storage container 16 (equipped with a level sensor for accurate measurement of water extraction volume) is used to measure the amount of water extracted.

[0054] The second lifting mechanism 17 that drives the suction head to rise and fall (such as a vertical robotic arm, the arm is driven by a stepper motor and has a vertical guide rail with a stroke of 50 cm and a positioning accuracy of ±0.5 mm).

[0055] The system parameters of the suction-type vortex generator module are shown in Table 4 below:

[0056] Table 4 System Parameters of the Suction-Type Vortex Generation Module

[0057] The suction-type vortex generation module is based on the principles of mass and angular momentum conservation. When fluid is locally extracted from a rotating fluid, the surrounding fluid converges towards the extraction point to replenish the removed mass. Under the influence of the Coriolis force, this centripetal flow deflects, forming a cyclonic rotation. Compared to the stirring method, the vortex generated by suction more closely resembles the physical mechanism of real tropical cyclones formed through low-level convergence, exhibiting better axisymmetry in the vortex structure and a more uniform distribution of the peripheral circulation. The vortex intensity is primarily determined by the extraction flow rate, duration, and background Coriolis parameters.

[0058] Specifically, such as Figure 4 As shown, the dual-vortex generation module includes:

[0059] Vertical guide rail 19 is mounted on frame 18;

[0060] A lifting plate 20 is slidably mounted on a vertical guide rail 19, and a horizontal moving module 21 is mounted on the lifting plate 20;

[0061] A third lifting mechanism 22 is fixedly installed on the top of the frame 18 and is used to drive the lifting plate 20 to rise and fall;

[0062] Two sets of vortex generating units are arranged side by side on a horizontal moving module 21. The horizontal moving module 21 is used to adjust the center distance between the two sets of vortex generating units. Each set of vortex generating units includes an inner cylinder 7 and an outer cylinder 8 arranged coaxially. The bottom of the outer cylinder 8 is open, and the top of the outer cylinder 8 is provided with a bearing 9 that cooperates with the inner cylinder 7.

[0063] The belt drive system includes a drive pulley 23, a timing belt 24, and a driven pulley 25. The drive pulley 23 and the driven pulley 25 are respectively mounted on the top of two inner cylinders 7, and the timing belt 24 is sleeved on the drive pulley 23 and the driven pulley 25.

[0064] The second drive motor is used to drive the drive wheel 23 to rotate. The drive wheel 23 drives the driven wheel 25 to rotate through the synchronous belt 24, thereby driving the two inner cylinders 7 to rotate. Differential speed control of the two vortices can be achieved by replacing the driven wheel 25 with different diameters. The driven wheel 25 specifications include 30, 35, 40, 50, 60 mm, etc., which can be combined to form a speed ratio range of 0.5 to 2.0, corresponding to different vortex intensity ratios.

[0065] The system parameters of the dual-vortex generation module are shown in Table 5 below:

[0066] Table 5 System Parameters of the Dual Vortex Generation Module

[0067] The dual-vortex generation module is used to simulate the interaction between two tropical cyclones, known as the Fujiwara effect. When two co-rotating vortices are close enough, they influence each other through their respective circulations: the tangential flow around the periphery of each vortex adducts the other, causing them to bind together and rotate cyclonicly around a common center. Historical observations indicate that tropical cyclones begin to interact when the distance is less than approximately 1400 km, the Fujiwara effect is significant when the distance is less than 650 km, and merging may occur when the distance is less than 300 km.

[0068] Preferably, such as Figure 5 As shown, the typhoon simulation system also includes a traffic flow simulation module, which includes:

[0069] A support platform 26, which is slidably mounted on an inclined base plate 4, is used to support a fixed terrain model 5;

[0070] The traction mechanism connecting the support platform 26 includes a traction rope 27, a guide pulley 28, a tension sensor 29, and a reel 30. The guide pulley 28 is mounted on the top of the water tank via a first horizontal rotating base 31, and the reel 30 is mounted on the bottom of the water tank via a second horizontal rotating base 32. The tension sensor 29 is mounted in the middle section of the traction rope 27. One end of the traction rope 27 is connected to the support platform 26, and the other end passes around the guide pulley 28 and is wound around the reel 30.

[0071] The third drive motor 33 (a stepper motor with a planetary reducer, which can achieve precise speed control of 0.1-5 cm / s) drives the winding reel 30 to wind or unwind. The third drive motor 33 is fixedly mounted on the second horizontal rotating base 32.

[0072] The support platform 26 is a transparent acrylic plate, 5-8 mm thick, supported on the inclined base plate 4 by miniature ball bearings 9 or PTFE gaskets, achieving low-friction sliding. The terrain model 5 is fixed to the support platform 26 by quick-release clips. The traction rope 27 is made of high-strength nylon thread, 0.3-0.5 mm in diameter, connected to the edge of the support platform 26, and led out of the water tank via guide pulley 28. The horizontal rotating base includes a 360° rotating base and an angle scale dial with an accuracy of 1°, used to set the dragging direction. The tension sensor 29 monitors the tension of the thread in real time, providing feedback control and thread breakage protection. The system parameters of the flow simulation module are shown in Table 6 below:

[0073] Table 6 System Parameters of the Drift Simulation Module

[0074] The flow simulation module addresses the technical challenge of generating a uniform background flow in a rotating system by employing the principle of relative motion equivalence. According to the Galilean transformation, a vortex moving at velocity V on stationary terrain is equivalent to the vortex remaining stationary while the terrain moves at velocity -V. Therefore, while maintaining the vortex's drift solely due to the β effect, the flow is simultaneously... Dragging the terrain can simulate an equivalent speed of... This method avoids the complexity of generating uniform inflow at the boundary of the rotating flume and minimizes disturbance to the flow field of the vortex itself. The direction of the flow is achieved by adjusting the dragging direction; dragging the terrain westward is equivalent to dragging eastward (guiding the vortex westward).

[0075] like Figure 6 As shown, the second aspect of the present invention provides a modular rotating water tank typhoon simulation experimental method based on the similarity law, comprising the following steps: S1, Obtain key physical parameters of the target typhoon prototype, including Coriolis parameters. Planetary β parameters (Describe the vortex gradient caused by the Earth's curvature), maximum wind speed Maximum wind speed radius Terrain features and height The terrain feature width 'a' and the equivalent depth of environmental fluids 'D'; S2, based on the principle of conservation of potential vorticity, calculate a set of core dimensionless parameters to characterize the dynamic similarity of the target typhoon prototype-typhoon simulation system; this stage aims to transform the physical characteristics of the real typhoon into dynamic control parameters. The core dimensionless parameters include at least the parameters calculated using the following formula: Planetary β parameters: This characterizes the relative strength of the Earth's rotation effect and vortex inertia; Terrain β parameter: This characterizes the effect of topographic forcing on vortices; in, The slope of the terrain; Geometric scale ratio: , representing the relative scale of topography and vortex.

[0076] S3. Based on the key physical parameters of the target typhoon prototype and the physical constraints of the experimental system, determine the basic parameters of the model, including the rotational angular velocity. and base slope Maximum wind speed of the model vortex and the maximum radius of the model vortex In this stage, boundary conditions are set based on the physical limitations of the experimental hardware. Since the laboratory cannot arbitrarily change all variables, three independent experimental parameters must be selected first. The selection of these parameters needs to take into account the size of the water tank, the range of motor speed, and the stability of the flow field (such as the range of Rossby number), which are known input items in the parameter conversion.

[0077] The maximum wind speed of the model vortex in the basic parameters of the model and the radius of maximum wind speed The type of vortex generator selected is determined by associating its operating parameters:

[0078] If a stirring vortex generation module is used, the operating parameters include the angular velocity of the inner cylindrical stirring. Duration of agitation ;

[0079] If a suction-type vortex generator module is used, the operating parameters include the suction flow rate. Duration of suction ,and Satisfying the approximation relation: ; in, These are the Coriolis parameters for the model.

[0080] S4. Based on the core dimensionless parameters and preset similarity conditions, determine the model-derived physical parameters for each module in the typhoon simulation system, including the model fluid depth. Model terrain width and model terrain height ;

[0081] The model fluid depth Based on far-field similarity conditions That is, it is required that the slope of the base plate in the experiment be generated The effect must be equivalent to the prototype planet. The effect, through formula substitution, derives the required fluid static depth for the model, and the calculation formula is as follows: ; This step ensures that the drift speed and path deflection mechanism of the vortex in the laboratory are consistent with those of a real typhoon.

[0082] The model terrain width According to the geometric similarity condition It is calculated using the following formula: ; The model terrain height Based on the similarity of topographic effects This ensures that the stretching effect of the vortex column remains proportional as the fluid crosses the terrain, and the height of the terrain in the model is inferred from this. The calculation formula is as follows: ;

[0083] Here, the subscript p represents the target typhoon prototype, and the subscript m represents the typhoon simulation system. Through the chained calculations of the above three steps, the massive real typhoon system can be accurately scaled down into a set of laboratory parameters including rotational speed, water depth, and terrain dimensions.

[0084] S5 configures the typhoon simulation system based on the model's basic parameters and derived physical parameters. It starts the basic rotating platform to the set angular velocity. After the fluid reaches solid rotation equilibrium, it generates vortices through the vortex generation module and uses the data acquisition and control module to record the experimental process of the interaction between the vortex and the terrain model.

[0085] Furthermore, when simulating the interaction of two typhoons:

[0086] The key physical parameters of the target typhoon prototype also include the distance d between the centers of the two typhoons and the vortex characteristic parameters of the two typhoons.

[0087] The core dimensionless parameter also includes the spacing parameter. and strength ratio parameter : ; ; In this context, the subscripts A and B represent Typhoon A and Typhoon B, which are two typhoons. The physical parameters derived from the model also include the model's double vortex spacing. According to similar conditions From the formula Calculated;

[0088] By adjusting the horizontal movement module of the dual vortex generator module, the center distance between the two sets of vortex generator units is set to... Furthermore, by configuring the diameter ratio of the driving pulley to the driven pulley in the belt drive system, the rotational speed ratio of the two inner cylinders is adjusted. This generates a double vortex with the target intensity ratio.

[0089] Preferably, when the typhoon simulation system includes a glide flow simulation module, the method further includes a glide flow field simulation step:

[0090] Obtain the environmental steering airflow velocity of the prototype typhoon And calculate dimensionless velocities. ;

[0091] Based on the principle of relative motion, determine the drag speed corresponding to the model. And the dragging direction, wherein the dragging direction is set to be opposite to the direction of the guiding airflow of the environment to be simulated;

[0092] During the experiment, once the vortex was generated and stabilized, the flow simulation module was simultaneously activated to control the third drive motor to drive the winding reel at a speed of The platform carrying the terrain model is pulled along a set direction and moved at a constant speed to simulate the modulation effect of environmental guiding airflow on the typhoon path, and the vortex motion trajectory under this combined condition is recorded by the data acquisition and control module.

[0093] The feasibility of the typhoon simulation system of this invention is illustrated below with a specific example:

[0094] Example 1: Parameter Design for a Single Typhoon Experiment

[0095] Prototype of the target typhoon: Taking a single typhoon as an example, typical parameters include: latitude φ≈ 22°N (corresponding to f0 = 2Ωsinφ ≈ 5.5×10⁻⁶). -5 s -1 β0 ≈ 2.28 × 10 -11 m -1 s -1 Maximum wind speed Maximum wind speed radius Terrain height (Central Mountain Range of Taiwan, China), topographic width a≈ 160km, tropospheric depth D≈10 km.

[0096] Step 1, calculate the core dimensionless parameters: ; ; .

[0097] Step 2, set the basic parameters of the model

[0098] Rotational parameters: The rotational angular velocity Ω determines the Coriolis parameters of the model. Depending on the equipment capacity, a typical selection is Ω = 0.5-1.0 rad / s (approximately 5-10 rpm), corresponding to... .

[0099] Base plate parameters: slope of inclined base plate The equivalent β effect of the model is determined. Based on geometric constraints, the tilt angle is typically chosen. Corresponding slope .

[0100] Vortex parameters: The vortex generation system determines the model vortex parameters. and Based on the specifications of the vortex generator and the fluid viscosity limitations, a typical selection is made. , .

[0101] In this example, Ω = 0.785 rad / s (7.5 rpm) is selected. = 0.0538 (θ ≈ 3°), = 6cm / s, = 3 cm.

[0102] Step 3: Determine the physical parameters derived from the model based on similarity conditions.

[0103] Based on similar conditions Calculation model fluid depth : ; This result verifies the feasibility of the parameter selection within the allowable water depth range (8-15 cm) of the equipment; Based on similar conditions Calculate the terrain half-width of the model : ; The corresponding terrain width is approximately 3.2 cm.

[0104] Based on similar conditions Calculate the terrain height of the model ; ; The parameter comparison table between the prototype and model of a single typhoon is shown in Table 7 below: Table 7. Parameter Comparison Table between Single Typhoon Prototype and Model

[0105] Step 4: Verify the similarity of the vortex structures.

[0106] Depth of liquid surface depression at the center of the vortex The relationship between surface concavity and maximum tangential wind speed for a vortex satisfying gradient wind equilibrium can be estimated using the gradient wind balance relationship: ; Regarding the prototype typhoon: (The equivalent height corresponding to the actual atmospheric pressure drop is approximately 300 m). For the model vortex: ; Calculate the vortex β parameter: ; (Assuming the prototype vortex β parameters are comparable); The similarity of the vortex structures was confirmed.

[0107] Step 5, verify relative terrain consistency Relative terrain β parameter It is a key indicator for measuring the strength of topographic effects relative to planetary beta effects and should be consistent between prototypes and models: ; ;

[0108] The two are completely equal, verifying the correctness of the parameter conversion.

[0109] Example 2: Parameter Design for a Double Vortex Experiment

[0110] In addition to the basic similarity conditions, the double vortex experiment needs to meet additional similarity conditions: Dimensionless spacing similarity: ,in ;

[0111] Similar strength ratios: ,in ;

[0112] The design of parameters for the dual-vortex experiment, based on the dynamic similarity law of the single-vortex experiment, further introduces key physical quantities describing the interaction between the two typhoons, specifically addressing the Fujiwhara Effect. Its design process comprises three coherent and progressively advancing technical processing steps:

[0113] First, step one involves determining the interactive characteristic parameters of the twin typhoon prototypes. This step aims to simplify the complex trajectories of historical twin typhoon cases (such as Parma-Melor) into quantifiable dimensionless indicators. In addition to extracting the basic parameters of a single typhoon, two key dimensionless numbers need to be calculated: (1) Dimensionless spacing parameter ,in This represents the straight-line distance between the centers of the two typhoons. The maximum wind speed radius of the main typhoon determines whether the two typhoons merge, rotate with each other, or only have path disturbances. (2) Strength ratio parameter , usually approximated as This characterizes the relative strength of the two typhoons. By analyzing historical observation data, the corresponding target simulation scenario (such as strong-weak interaction or equal-strength alternation) is determined. and The numerical range serves as the control objective for the experimental design.

[0114] Secondly, step two involves calculating the geometric spacing and mechanical configuration of the model. This step transforms the aforementioned dimensionless parameters into specific mechanical settings for the dual-vortex generation module. This is done after the model's characteristic radius has been determined based on the single-vortex similarity law. Under the premise of similar conditions The physical distance between the two vortex generators in the laboratory can be directly calculated. Subsequently, based on the calculated The value (typically in the range of 15-50 cm) is used to precisely position and lock the horizontal moving module of the dual vortex generation module to ensure geometric similarity under the initial experimental conditions.

[0115] Finally, step three involves deriving the differential transmission ratio and selecting the pulley, which is the core technical method for simulating the asymmetric intensity of two typhoons. Based on the principle of turbulent generation, vortex intensity (vorticity) is... ) and the rotational angular velocity of the inner cylinder Proportional. To satisfy the similarity condition. The rotational speed ratio of the two generators in the laboratory needs to meet the following requirements. Since the dual-vortex generator module uses a single motor drive combined with a belt drive system, its speed ratio is determined by the diameter ratio of the driving and driven pulleys (i.e., Therefore, the technical processing needs to be based on the target strength ratio. Choose a suitable diameter combination from standardized pulley kits (e.g., 30, 40, 50, 60 mm). For example, to simulate a weak-strong interaction with an intensity ratio of 0.5, a pulley combination with a diameter ratio of 2:1 should be used and mounted on the two generator shafts. This mechanical differential design allows for the accurate reproduction of the relative intensity characteristics of two typhoons under a single power source.

[0116] For double-vortex experiments, the dimensionless spacing similarity must additionally be satisfied: If the distance between the two prototype typhoons... = 1000 km, prototype Then the dimensionless spacing is: ; Model Spacing ;

[0117] The strength ratio γ is achieved by changing the diameter of the driven wheel. Let the diameter of the driving wheel be D. A = 40 mm. If γ = 1.2 (the rotational speed of a strong vortex is 1.2 times that of a weak vortex) is required, then the diameter of the driven wheel can be selected. Configuration.

[0118] The parameter comparison table between the prototype and model of the two typhoons is shown in Table 8 below:

[0119] Table 8. Parameter Comparison Table between the Prototype and Model of the Two Typhoons

[0120] A typical dual-vortex experiment configuration is shown in Table 9 below:

[0121] Table 9 Typical Double Vortex Experiment Configuration

[0122] Example 3: Design of experimental parameters for the flow field

[0123] The design of the jet flow field experimental parameters utilizes the "principle of relative motion" to solve the problem of background flow simulation in a rotating reference frame. Its core lies in converting the jet velocity field in the real atmosphere into accurate drag parameters for a terrain model in the laboratory. This design method includes three rigorous technical processing steps, the specific derivation and calculation process of which are as follows:

[0124] First, step one involves quantifying the prototype jet stream dynamics. This step aims to extract representative steering flow parameters from the complex atmospheric environment. It requires analyzing the average velocity vector of the target typhoon case (such as a westward-moving path guided by the subtropical high). Assuming the typhoon's movement is primarily driven by environmental advection and... The drift contribution, in this simplified model, will be deducted. The motion component after drifting is considered as the ambient flow speed. Next, dimensionless driving flow parameters are defined. This dimensionless number characterizes the ratio of the environmental flow field to the intensity of the vortex's own circulation, and is a key dynamic indicator that determines the degree of vortex path deflection (such as whether it is blocked by terrain or flows around it).

[0125] Secondly, step two involves deriving the model's drag velocity and direction. This step converts atmospheric dynamic parameters into mechanical control commands for the runoff simulation module. Based on the application of Galilean transformation in rotating frames, in a real environment, vortices relative to stationary terrain exhibit velocity... Movement is dynamically equivalent to the terrain moving relative to a stationary vortex at a velocity- Move. Therefore, firstly, based on similarity conditions... Calculate the equivalent flow velocity required for the laboratory model Because the laboratory uses a terrain-dragging method, the actual set dragging speed... Numerically equal to However, its direction needs to be determined. Reverse processing. For example, to simulate westward movement in the real atmosphere. The flow of traffic, in the laboratory, requires setting the terrain model to the east ( )move.

[0126] Finally, step three involves calculating the towing distance and controlling the time. This step aims to ensure the feasibility of the experiment and the completeness of the data acquisition. Based on the calculated towing speed... and the characteristic scale of the model terrain (Including the effective range of vortex and terrain interaction, typically set to 2-3 times the terrain width), calculate the required total towing distance. and effective experimental time This itinerary needs to be verified. Whether it is within the physical length limit of the water tank in the flow simulation module (e.g., 30-80 cm), and set the acceleration / deceleration curve of the stepper motor accordingly to ensure that the terrain reaches a stable set speed before entering the interaction zone. This eliminates the non-physical interference of inertia on the flow field. Through this precise kinematic planning, environmental vegetation effects of different intensities and directions can be successfully reproduced in a stationary rotating fluid.

[0127] For the turbulence field experiment, the dimensionless turbulence similarity must be satisfied: If the prototype flow rate is... ,prototype ,but: ;

[0128] Model dragging speed ;

[0129] The dragging direction is determined according to the principle of relative motion: if it is necessary to simulate an eastward flow (guiding the vortex westward), then the terrain should be dragged westward (in the 270° direction); the parameter comparison table between the typhoon prototype and the model that incorporates the flow field is shown in Table 10 below:

[0130] Table 10 shows the parameter comparison between the typhoon prototype and model with introduced runoff field.

[0131] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A modular rotating water tank typhoon simulation system based on the similarity law, characterized in that, include: The basic rotating platform includes a drive assembly (1), a platform surface (2) and a transparent water tank (3). The transparent water tank (3) is fixedly installed on the platform surface (2). The drive assembly (1) is used to drive the platform surface (2) to rotate around a vertical axis. The terrain simulation module includes an inclined base plate (4) placed at the bottom of the transparent water tank (3) with an adjustable inclination angle, and a three-dimensional terrain model (5) fixed on the inclined base plate (4); The vortex generation module is installed on the base rotating platform through a detachable interface (6) and is used to generate cyclonic vortices in the fluid of the transparent water tank (3); the vortex generation module includes at least one of a stirring vortex generation module, a suction vortex generation module and a dual vortex generation module. The data acquisition and control module is used to control the operating parameters of the basic rotating platform and the vortex generation module, and to collect and record the flow field visualization data during the experiment.

2. The modular rotating water tank typhoon simulation system based on the similarity law as described in claim 1, characterized in that, The stirring vortex generation module includes: An inner cylinder (7) and an outer cylinder (8) are coaxially arranged. The bottom of the outer cylinder (8) is open, and the top of the outer cylinder (8) is provided with a bearing (9) that mates with the inner cylinder (7). A first drive motor (10) drives the inner cylinder (7) to rotate about its axis; A first lifting mechanism (11) is used to drive the inner cylinder (7) and the outer cylinder (8) to rise and fall vertically as a whole.

3. The modular rotating water tank typhoon simulation system based on the similarity law as described in claim 1, characterized in that, The suction-type vortex generation module includes: The suction head is provided with a conical suction nozzle (12) at the lower end, and an annular guide shroud (13) is provided around the suction head; A suction tube (14) connected to the suction head; A suction pump (15) installed on the suction pipeline (14); Water storage container (16) used to measure the amount of water extracted; A second lifting mechanism (17) that drives the suction head to rise and fall.

4. The modular rotating water tank typhoon simulation system based on the similarity law as described in claim 1, characterized in that, The dual-vortex generation module includes: Vertical guide rails (19) are mounted on the frame (18); A lifting plate (20) is slidably mounted on a vertical guide rail (19), and a horizontal moving module (21) is mounted on the lifting plate (20); A third lifting mechanism (22) is fixedly installed on the top of the frame (18) for driving the lifting plate (20) to rise and fall; Two sets of vortex generating units are arranged side by side on a horizontal moving module (21). The horizontal moving module (21) is used to adjust the center distance between the two sets of vortex generating units. Each set of vortex generating units includes an inner cylinder (7) and an outer cylinder (8) arranged coaxially. The bottom of the outer cylinder (8) is open, and the top of the outer cylinder (8) is provided with a bearing (9) that cooperates with the inner cylinder (7). The belt drive system includes a drive pulley (23), a timing belt (24), and a driven pulley (25). The drive pulley (23) and the driven pulley (25) are respectively mounted on the top of two inner cylinders (7), and the timing belt (24) is sleeved on the drive pulley (23) and the driven pulley (25). The second drive motor is used to drive the drive wheel (23) to rotate. The drive wheel (23) drives the driven wheel (25) to rotate through the synchronous belt (24), thereby driving the two inner cylinders (7) to rotate.

5. The modular rotating water tank typhoon simulation system based on the similarity law as described in claim 1, characterized in that, The typhoon simulation system also includes a traffic flow simulation module, which includes: A support platform (26) is slidably mounted on an inclined base plate (4) for supporting a fixed terrain model (5); The traction mechanism connecting the support platform (26) includes a traction rope (27), a guide pulley (28), a tension sensor (29), and a winding reel (30). The guide pulley (28) is mounted on the top of the water tank via a first horizontal rotating base (31), and the winding reel (30) is mounted on the bottom of the water tank via a second horizontal rotating base (32). The tension sensor (29) is mounted in the middle section of the traction rope (27). One end of the traction rope (27) is connected to the support platform (26), and the other end passes around the guide pulley (28) and is wound around the winding reel (30). A third drive motor (33) drives the winding reel (30) to wind or unwind, and the third drive motor (33) is fixedly mounted on the second horizontal rotating base (32).

6. A modular rotating water tank typhoon simulation experimental method based on the similarity law, based on the typhoon simulation system according to any one of claims 1-5, characterized in that, Includes the following steps: Obtain key physical parameters of the target typhoon prototype, including the Coriolis parameter. Planetary β parameters Maximum wind speed Maximum wind speed radius Terrain features and height The terrain feature width 'a' and the equivalent depth of environmental fluids 'D'; Based on the principle of potential vorticity conservation, a set of core dimensionless parameters are calculated to characterize the dynamic similarity of the target typhoon prototype-typhoon simulation system. Based on the key physical parameters of the target typhoon prototype and the physical constraints of the experimental system, the basic parameters of the model are determined, including the rotational angular velocity. and base slope Maximum wind speed of the model vortex and the maximum radius of the model vortex ; Based on the core dimensionless parameters and preset similarity conditions, the model-derived physical parameters for each module in the typhoon simulation system are determined, including the model fluid depth. Model terrain width and model terrain height ; The typhoon simulation system is configured based on the basic parameters and derived physical parameters of the model. The basic rotating platform is started to the set angular velocity. After the fluid reaches solid rotation equilibrium, vortices are generated through the vortex generation module, and the experimental process of the interaction between the vortex and the terrain model is recorded using the data acquisition and control module.

7. The modular rotating water tank typhoon simulation experimental method based on the similarity law as described in claim 6, characterized in that, The core dimensionless parameters include at least the parameters calculated using the following formula: Planetary β parameters: ; Terrain β parameter: ; in, The slope of the terrain; Geometric scale ratio: ; The model fluid depth Based on similar conditions It is calculated using the following formula: ； The model terrain width Based on similar conditions It is calculated using the following formula: ； The model terrain height Based on similar conditions It is calculated using the following formula: ； In this context, the subscript p represents the target typhoon prototype, and the subscript m represents the typhoon simulation system.

8. The modular rotating water tank typhoon simulation experimental method based on the similarity law as described in claim 7, characterized in that, When simulating the interaction of two typhoons: The key physical parameters of the target typhoon prototype also include the distance d between the centers of the two typhoons and the vortex characteristic parameters of the two typhoons. The core dimensionless parameter also includes the spacing parameter. and strength ratio parameter : ； ； In this context, the subscripts A and B represent Typhoon A and Typhoon B, which are two typhoons. The physical parameters derived from the model also include the model's double vortex spacing. According to similar conditions From the formula Calculated; By adjusting the horizontal movement module of the dual vortex generator module, the center distance between the two sets of vortex generator units is set to... Furthermore, by configuring the diameter ratio of the driving pulley to the driven pulley in the belt drive system, the rotational speed ratio of the two inner cylinders is adjusted. This generates a double vortex with the target intensity ratio.

9. The modular rotating water tank typhoon simulation experimental method based on the similarity law as described in claim 7, characterized in that, The maximum wind speed of the model vortex in the basic parameters of the model and the radius of maximum wind speed The type of vortex generator selected is determined by associating its operating parameters: If a stirring vortex generation module is used, the operating parameters include the angular velocity of the inner cylindrical stirring. Duration of agitation ; If a suction-type vortex generator module is used, the operating parameters include the suction flow rate. Duration of suction ,and Satisfying the approximation relation: ； in, These are the Coriolis parameters for the model.

10. The modular rotating water tank typhoon simulation experimental method based on the similarity law as described in claim 7, characterized in that, When the typhoon simulation system includes a glide flow simulation module, the method further includes a glide flow field simulation step: Obtain the environmental steering airflow velocity of the prototype typhoon And calculate dimensionless velocities. ; Based on the principle of relative motion, determine the drag speed corresponding to the model. And the dragging direction, wherein the dragging direction is set to be opposite to the direction of the guiding airflow of the environment to be simulated; During the experiment, once the vortex was generated and stabilized, the flow simulation module was simultaneously activated to control the third drive motor to drive the winding reel at a speed of The platform carrying the terrain model is pulled along a set direction and moved at a constant speed to simulate the modulation effect of environmental guiding airflow on the typhoon path, and the vortex motion trajectory under this combined condition is recorded by the data acquisition and control module.

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