A device and method for measuring the unsteady flow field of a ship model steering state in a wind tunnel

Abstract

The present application relates to a kind of wind tunnel ship model steering state unsteady flow field test measurement device and test method.It includes wind tunnel test section, wing rudder model, steering mechanism, cave top and cave side three-dimensional coordinate positioning system, and respectively installed on its high-speed camera and high-frequency laser sheet light source;Steering mechanism drives rudder blade to rotate around rudder shaft according to predetermined rate and amplitude, simulates steering movement;Two sets of three-dimensional coordinate positioning system independently adjusts the spatial position of high-speed camera and sheet light source along three orthogonal directions, to adapt to the dynamic change of test area in steering process, so that laser sheet light plane and test section are accurately overlapped, and camera shooting light path is perpendicular to test section.The light path positioning of the present application is accurate, can effectively isolate cave body vibration interference and inhibit wall laser reflection, can capture the time history dynamic data of unsteady flow structure around wing rudder with high space-time resolution, provides reliable test support for ship steering state flow separation mechanism research and stealthy evaluation.

Description

Technical Field

[0001] This invention relates to the field of experimental measurement technology, and in particular to an experimental measurement device and method for unsteady flow field testing of a ship model in a wind tunnel under steering conditions. Background Technology

[0002] With the development of experimental measurement technology, related technologies for experimental measurement of appendage flow fields under ship maneuvering conditions have emerged. This technology is mainly used to study the flow topology and evolution mechanism around the ship model under steering conditions. It can provide technical reserves for ship flow stealth assessment and optimization technology, and is of great significance for improving ship flow stealth performance and reducing flow-induced noise. This leads to the development of related methods and devices for measuring unsteady flow fields under ship model steering conditions based on wind tunnel testing.

[0003] In related technologies, the measurement of unsteady flow fields around ship models is limited to laboratory constrained models. The experimental testing equipment used only supports fixed model attitude angles and rudder angles. Through such constrained models and corresponding testing equipment, relevant data on the flow field around the ship model are collected and analyzed to obtain preliminary flow characteristics.

[0004] However, the aforementioned measurement methods and corresponding test equipment for laboratory restraint models have significant technical defects and application limitations, making it impossible to conduct unsteady flow field test measurements of ship model steering in a wind tunnel. First, it is impossible to establish a simulation of steering motion under the predetermined steering speed of the ship model, making it difficult to achieve precise control of the rudder angle change law and integration of a high-strength anti-torsion steering mechanism under conditions of wind speed environment and limited space scale. Secondly, for the dynamic process of steering motion, there is a lack of non-contact experimental measurement technology with high spatiotemporal resolution around the wing and rudder, which makes it impossible to achieve synchronous triggering of data acquisition and difficult to provide the time-history dynamic data required for parameterized statistical analysis of flow characteristics under steering conditions. Third, it cannot adapt to the dynamic changes in the test area caused by the reciprocating rotation of the rudder blade around the rudder axis during steering maneuvers, making it difficult to accurately capture the flow evolution structure in the near-wing rudder area. Consequently, it cannot fully grasp the flow field change patterns around the ship's appendages under steering conditions, and cannot provide reliable technical support for the assessment and optimization of ship flow stealth. Summary of the Invention

[0005] To address the shortcomings of existing production technologies, the applicant provides a test and measurement device and method for unsteady flow field measurement in the steering state of a ship model in a wind tunnel, thereby enabling high spatiotemporal resolution measurement of unsteady flow in the steering state of a ship model.

[0006] The technical solution adopted in this invention is as follows: This invention provides a test and measurement device for unsteady flow field of a ship model in a wind tunnel under steering conditions. The device includes a wind tunnel test section having a height direction, a first horizontal direction, and a second horizontal direction. A wing-rudder model is installed inside the wind tunnel test section. The wing-rudder model includes a stabilizing wing body and rudder blades that rotate relative to the stabilizing wing body. The steering mechanism is connected to the rudder blade and is used to drive the rudder blade to reciprocate around the rudder shaft at a predetermined steering speed and amplitude. A three-dimensional coordinate positioning system for the tunnel top is installed above the top surface of the wind tunnel test section; A three-dimensional coordinate positioning system for the tunnel side is installed on one side of the wind tunnel test section in the second horizontal direction; A high-speed camera, mounted on the three-dimensional coordinate positioning system at the top of the tunnel, is used to capture images of tracer particles vertically downwards from the top of the wind tunnel test section. A high-frequency laser sheet light source is installed on the tunnel side three-dimensional coordinate positioning system to provide lateral horizontal illumination from the wind tunnel test section to form a laser sheet light covering the test section; The tunnel top three-dimensional coordinate positioning system and the tunnel side three-dimensional coordinate positioning system are respectively used to adjust the spatial positions of the high-speed camera and the high-frequency laser sheet light source in the first horizontal direction, the second horizontal direction, and the height direction, so as to adapt to the dynamically changing test area caused by the rotation of the rudder blade.

[0007] Its beneficial effects are as follows: By mounting a high-speed camera and a high-frequency laser sheet light source on the three-dimensional coordinate positioning system on the top and side of the tunnel, respectively, the optical devices in the flow field testing system have the ability to independently adjust their spatial position in three directions. This allows them to adapt to the dynamic changes in the test area caused by the reciprocating rotation of the rudder blade around the rudder axis during steering movements, enabling the tracking and capture testing of unsteady flow structures in the spatial region near the rudder. Simultaneously, by employing a non-contact flow field testing method with high spatiotemporal resolution, combined with the precise control of the rudder angle change law by the steering mechanism, a technical system for testing and measuring unsteady flow fields in the steering state of ship models has been established. This system enables high spatiotemporal resolution testing and identification of transient unsteady fine flow structures during ship model steering movements, expanding and improving the content of ship model flow field testing technology in wind tunnels. It provides reliable experimental data support for the study of the correlation between ship maneuvering movements and unsteady flow fields, as well as the analysis of the flow separation mechanism and evolution mechanism of steering movements.

[0008] As a further improvement, the hole-side three-dimensional coordinate positioning system includes a base, a first linear module disposed on the base along a first horizontal direction, a second linear module disposed along a height direction and fixed to the sliding end of the first linear module, and a third linear module disposed along a second horizontal direction and fixed to the sliding end of the second linear module; a mounting base is fixed on the sliding end of the third linear module, and the high-frequency laser chip light source is disposed on the mounting base.

[0009] Its beneficial effects are as follows: by adopting a three-level linear module stacked and connected in three mutually perpendicular directions, a compact and motion-decoupled three-dimensional positioning mechanism is constructed. It can independently adjust the position of the high-frequency laser sheet light source in the lateral space of the wind tunnel test section along the first horizontal direction, the second horizontal direction, and the height direction. The positioning accuracy is high and the motion range is controllable, which effectively ensures the precise coincidence of the laser sheet light plane with the dynamically changing test section, thereby reducing the test uncertainty introduced by the optical path deviation and improving the quality of particle image acquisition.

[0010] As a further improvement, the tunnel top three-dimensional coordinate positioning system includes a fourth linear module arranged along a first horizontal direction, a linear guide rail symmetrically arranged with the fourth linear module in a second horizontal direction, a connector whose two ends respectively cooperate with the sliding end of the fourth linear module and the linear guide rail and are driven by the fourth linear module to move along the first horizontal direction, a fifth linear module arranged along the second horizontal direction and fixed to the connector, and a sixth linear module arranged along the height direction and fixed to the sliding end of the fifth linear module; the sliding end of the sixth linear module is equipped with a camera gimbal for mounting the high-speed camera.

[0011] Its beneficial effects are as follows: The structure of the fourth linear module and the linear guide rail symmetrically arranged in the second horizontal direction, with the connecting piece spanning between the two to form a gantry support structure, ensures that the subsequent module with the high-speed camera is subjected to balanced force and moves smoothly when moving along the first horizontal direction. This significantly improves the structural rigidity and movement stability of the tunnel top positioning system, effectively avoids vibration and deformation caused by large span or cantilever stress, and ensures that the high-speed camera's imaging optical path is always perpendicular to the test section during long-term data acquisition, further improving the reliability and repeatability of the test data.

[0012] As a further improvement, the steering mechanism includes a drive motor, a rudder stalk that is driven by the drive motor, and a rudder sleeve that is fixedly sleeved on the outer periphery of the rudder stalk; the rudder sleeve is fixedly connected to the rudder blade, the rudder stalk extends from the bottom of the stabilizer body into the rudder sleeve, and the drive motor drives the rudder blade to rotate through the rudder stalk and the rudder sleeve.

[0013] Its beneficial effects are as follows: through the fitting structure of the rudder stock and the rudder sleeve, the precise transmission of the rudder blade's rotational motion around the rudder shaft is realized. The overall structure is small and compact, and can be installed and integrated into the bottom of the wing-rudder model or the internal space of the ship model. It has almost no interference with the flow structure around the model when the ship model is being steered, ensuring the authenticity and accuracy of the flow field test results, and solving the problem of integrating the steering mechanism under the limited space of the wind tunnel test.

[0014] Furthermore, the steering mechanism also includes a positioning pin, which passes through the end of the stabilizer wing and is embedded in the rudder blade, and the centerline of the positioning pin coincides with the centerline of the rudder shaft of the rudder blade.

[0015] Its beneficial effects are as follows: the positioning pin passes through the end of the stabilizer wing and is embedded in the rudder blade, and the centerline coincides with the centerline of the rudder shaft. On the one hand, it provides a precise rotation positioning reference for the rudder blade, ensuring that the rudder blade rotates stably around the predetermined axis without wobbling during the steering motion. On the other hand, it plays a role in structural limit and stable support, improving the torsional strength and motion accuracy of the steering mechanism under high-frequency reciprocating steering conditions, and providing a reliable mechanism guarantee for steering flow field testing under high wind speed and high Reynolds number conditions.

[0016] Specifically, the stabilizing wing tip of the wing-rudder model is made of a fully transparent material to provide an unobstructed field of view for the high-speed camera; the stabilizing wing body and rudder blade surface are coated with a matte paint layer.

[0017] Its beneficial effects are as follows: the stabilizer tip is made of a fully transparent material, which can avoid the end structure from obstructing the field of view when the camera shoots vertically downward from the top of the wind tunnel, and completely capture the tracer particle image in the laser sheet light plane; the stabilizer body and rudder blade surface are sprayed with a matte paint layer, which can effectively prevent strong wall reflection when the high-energy pulsed laser irradiates the model surface, and avoid the reflected light from interfering with the clarity and signal-to-noise ratio of the particle image, thereby significantly improving the accuracy of flow structure identification and the quality of test data.

[0018] As a further improvement, a transparent glass cover is provided on the top surface of the wind tunnel test section, and the three-dimensional coordinate positioning system of the tunnel top is located above the transparent glass cover; a wind tunnel porthole is provided on one side wall of the wind tunnel test section in the second horizontal direction, and the three-dimensional coordinate positioning system of the tunnel side is located outside the wind tunnel porthole.

[0019] Its beneficial effects are as follows: By placing the three-dimensional coordinate positioning system on the top and side of the wind tunnel above the transparent glass cover and outside the wind tunnel window of the wind tunnel test section, respectively, the mounting base of the positioning system is physically isolated from the wind tunnel test section, avoiding the transmission of wind tunnel vibration to the flow field testing system during wind tunnel operation and introducing additional testing uncertainties. At the same time, the optical path penetrates into the interior of the test section through the transparent glass cover and the wind tunnel window, respectively, effectively isolating external environmental disturbances while ensuring the integrity of the optical path required for flow field measurement, and significantly improving the measurement accuracy and stability of the testing system.

[0020] As a further improvement, the device also includes a steering control system electrically connected to the steering mechanism, which controls the steering mechanism to perform two steering motion modes: static fixed rudder angle or dynamic oscillating rudder angle.

[0021] Its beneficial effects are as follows: the steering control system supports switching between two steering motion modes, namely static fixed rudder angle and dynamic swing rudder angle. It can not only meet the steady-state flow field measurement requirements under the fixed rudder angle state in traditional restrained model tests, but also realize the dynamic steering motion simulation under the predetermined steering speed and amplitude. This allows a single device to cover both steady-state and dynamic test conditions, enhancing the applicability and versatility of the device and enriching the test content of ship model flow field testing in wind tunnels.

[0022] This invention also provides a method for testing and measuring the unsteady flow field of a ship model in a wind tunnel under steering conditions, using the test and measurement device for the unsteady flow field of a ship model in a wind tunnel under steering conditions described in any of the above claims, comprising the following steps: Install the wing rudder model and steering mechanism, and connect the steering mechanism to the steering control system; Based on the normal direction of the flow field test section, the installation positions of the high-frequency laser sheet light source and the high-speed camera are arranged so that the high-frequency laser sheet light source is installed on the side of the wind tunnel test section, so that the laser sheet light shines horizontally from the side and covers the test section. The high-speed camera is installed on the top of the wind tunnel test section to capture images of tracer particles with the optical path perpendicular to the test section. The spatial positions of the high-speed camera and high-frequency laser sheet light source are finely adjusted by the three-dimensional coordinate positioning system on the top of the tunnel and the three-dimensional coordinate positioning system on the side of the tunnel, so that the light plane of the laser sheet coincides with the test section and the camera's shooting light path is perpendicular to the test section, thus completing the system debugging and calibration. Start the steering control system, set the steering rate and steering amplitude, and apply steering control commands to the steering mechanism to drive the rudder blades to perform steering motion; start the test system and collect dynamic data of the flow field time history after the steering motion has been performed for a predetermined period.

[0023] Its beneficial effects are as follows: This method integrates steering motion simulation with high spatiotemporal resolution flow field testing technology. By accurately calibrating and adjusting the optical test path and spatial position before the experiment, and starting data acquisition after multiple cycles of steering motion, it ensures that the acquired data can fully reflect the dynamic evolution characteristics of the flow field under steering conditions. It provides rich time-history dynamic data for parametric statistical analysis of flow structure, separation morphology and vortex evolution law under steering conditions. It has the advantages of clear experimental process, strong operability and high reliability of measurement results.

[0024] As a further improvement, when arranging the installation positions of the high-frequency laser sheet light source and the high-speed camera, a mode of side-illuminated laser and vertical camera shooting is adopted; the normal direction of the test section is the vertical direction of the wind tunnel test section, and the test section position is taken as the spanwise center position of the rudder blade.

[0025] Its beneficial effects are as follows: the optical path layout mode of side-illuminated laser and vertical camera shooting allows the laser sheet light to cover the center position of the rudder blade spanwise from the side in a manner parallel to the test section, and the camera shooting vertically from the top can completely receive the scattered particle light signal in the sheet light plane. This layout effectively avoids interference and obstruction of the optical path during the rotation of the rudder blade, and at the same time can focus on the center region of the rudder spanwise where the steering motion has the most significant impact, so as to obtain the key flow field information reflecting the flow separation and vortex structure evolution characteristics around the wing and rudder to the maximum extent. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 In order to be in Figure 1 A schematic diagram of the structure after the wind tunnel test section has been removed from the original design.

[0028] Figure 3 This is a front view of the steering mechanism and rudder model of the present invention.

[0029] Figure 4 This is a three-dimensional schematic diagram of the steering mechanism and wing-rudder model of the present invention.

[0030] Figure 5 This is a three-dimensional schematic diagram of the structure of the device after it is connected to the control cabinet in a practical application of the present invention.

[0031] The components include: 1. Steering control touchscreen; 2. Steering control cabinet; 3. Wind tunnel test section; 4. Steering mechanism; 5. Three-dimensional coordinate positioning system on the tunnel side; 6. Three-dimensional coordinate positioning system on the tunnel top; 7. High-speed camera; 8. High-frequency laser sheet light source; 9. Transparent glass cover; 10. Wing and rudder model; 11. Laser sheet light source; 12. Wind tunnel porthole; 13. Positioning pin; 14. Rudder stock; 15. Rudder sleeve; 16. Connecting rod; 17. Connecting plate; 18. Power input module; 19. Control input module; 20. Drive motor; 21. Transmission track; 22. Stabilizer wing tip; 23. Rudder blade; 24. Stabilizer wing body; 501. Base; 502. First linear module; 503. Second linear module; 504. Third linear module; 505. Mounting bracket; 601. Fourth linear module; 602. Linear guide rail; 603. Connector; 604. Fifth linear module; 605. Sixth linear module; 606. Camera gimbal. Detailed Implementation

[0032] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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 the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" of the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] This invention provides a test and measurement device for unsteady flow fields in the steering state of a ship model in a wind tunnel. The overall structure is described in conjunction with the reference. Figure 1 and Figure 2 As shown.

[0038] The device mainly includes a wind tunnel test section 3 for providing a stable wind speed environment, a wing-rudder model 10 with integrated steering functions, a steering mechanism 4 for dynamic steering simulation, a tunnel-side three-dimensional coordinate positioning system 5 and a tunnel-top three-dimensional coordinate positioning system 6 for supporting and moving optical test components, as well as a high-speed camera 7 and a high-frequency laser sheet light source 8 for flow field acquisition; in addition, it also includes a steering control system that provides control commands and electrical power to the steering mechanism 4, which consists of... Figure 5 The steering control touch screen 1 and steering control cabinet 2 shown are combined.

[0039] Based on the structure of the wind tunnel test section 3, the present invention defines three mutually orthogonal directions: the first horizontal direction, the second horizontal direction, and the height direction, and constructs a spatial positioning reference for each component based on these directions.

[0040] The wind tunnel test section 3 is a frame structure with a closed or semi-closed test chamber, which has a top surface and a bottom surface opposite each other in the height direction. On the top surface, an optical path window is opened and a transparent glass cover plate 9 is installed. The wind tunnel test section 3 has two opposite side walls in the second horizontal direction. A wind tunnel window 12 is opened on the side wall where the sheet light source needs to be arranged. The transparent glass cover plate 9 and the wind tunnel window 12 together form a transparent barrier between the external optical test system and the internal test area, which not only ensures the smooth flow of light but also maintains the integrity of the wind tunnel flow field.

[0041] Inside the central area of ​​wind tunnel test section 3, a wing-rudder model 10 is installed, the main structure of which is as follows: Figure 3 and Figure 4 As shown, it includes a stabilizer body 24, a stabilizer tip 22, and a movable rudder blade 23; The rudder blade 23 is located at the trailing edge of the main body of the stabilizer and can rotate relative to the main body of the stabilizer 24 around the rudder shaft to simulate the steering attitude changes of a real ship's attachment.

[0042] Understandably, in order to achieve precise control over the motion of the rudder blade 23, a steering mechanism 4 is configured and integrated at the bottom of the wing-rudder model 10. This steering mechanism 4 can be housed inside or at the bottom of the wing-rudder model 10 to avoid introducing unnecessary turbulence structures into the wind tunnel flow field.

[0043] Specifically, the transmission and support core of the steering mechanism 4 consists of a positioning pin 13, a rudder stock 14, a rudder sleeve 15, a connecting rod 16, a connecting plate 17, a power input module 18, a control input module 19, a drive motor 20, and a transmission track 21. During installation, the rudder sleeve 15 is fully embedded into the rudder shaft position of the rudder blade 23 and fixedly connected thereto. The top cross section of the rudder sleeve 15 is preferably square to ensure the stability of torque transmission, and the remaining cross section is circular to facilitate rotational fit. The shape of the rudder stock 14 matches the inner cavity of the rudder sleeve 15. It extends from the bottom of the stabilizer body 24 into the interior of the rudder sleeve 15. When the rudder stock 14 is driven by a torque and rotates, it will drive the rudder blade 23 to rotate synchronously around the rudder shaft through the rudder sleeve 15.

[0044] During this dynamic process, the main body 24 of the stabilizer and the tip 22 of the stabilizer remain stationary, thus realistically reproducing the physical boundary conditions of the stabilizer remaining stationary while the control surface oscillates.

[0045] Furthermore, in order to provide a precise coaxiality reference for rotation and to withstand radial loads, a positioning pin 13 is provided. The positioning pin 13 passes through the top hole of the stabilizer end 22 and is embedded into the corresponding blind hole on the top of the rudder blade 23, ensuring that the center line of the positioning pin 13 coincides with the center line of the rudder shaft of the rudder blade 23.

[0046] As a power source, the drive motor 20 can be a single-axis rotary motor with high torsional resistance in practical applications to meet the steering torque requirements in high wind speed and high Reynolds number environments and ensure response accuracy during high-frequency reciprocating motion.

[0047] The rotational output of the drive motor 20 is transmitted to the rudder 14 via the transmission track 21.

[0048] The overall structural rigidity of the steering mechanism 4 is ensured by the connecting rod 16 and the connecting plate 17. The connecting rod 16 is arranged in parallel with the rudder spool 14 and embedded in the pre-embedded structure of the stabilizer body 24. It is fixedly connected to the stabilizer body 24 through the connecting plate 17 to form a stable gantry support structure.

[0049] The power and control commands of the steering mechanism 4 are connected through the power input module 18 and the control input module 19, which are connected to the external steering control cabinet 2.

[0050] Understandably, in order to obtain clear and interference-free tracer particle images in the test area where unsteady and spatially dynamic changes are caused by steering motion, the present invention designs the physical material and surface properties of the wing-rudder model 10.

[0051] Since the shooting angle of the high-speed camera 7 is vertically downward from the top of the hole, if the stabilizer tip 22 is made of conventional opaque material, it will severely obstruct the shooting view.

[0052] Therefore, the stabilizing wing tip 22 is made of fully transparent acrylic material, forming an unobstructed optical observation window. Meanwhile, because the high-energy pulsed laser light 11 emitted by the high-frequency laser light source 8 produces extremely strong wall reflection light when it shines on the model surface, this would severely overwhelm the scattered light signal of the tracer particles. To address this, the main body of the stabilizing wing 24 and the rudder blade 23 are made of ABS material, and their surfaces are coated with a black matte paint layer to maximize the absorption or diffuse reflection of laser energy and suppress the damage of high-intensity reflected light to the signal-to-noise ratio of the particle image.

[0053] In order to achieve optical non-contact measurement of the flow field and to adapt to the continuous dynamic changes in the test area caused by the reciprocating rotation of the rudder blade 23 around the rudder axis during steering, the present invention is configured with an optical layout scheme based on two independent three-dimensional coordinate positioning systems; the test optical path follows the mode of "side-facing laser illumination and vertical camera shooting".

[0054] The three-dimensional coordinate positioning system 5 on the side of the tunnel is responsible for carrying and positioning the high-frequency laser sheet light source 8, which is located outside the wind tunnel window 12.

[0055] The specific structure of the tunnel-side three-dimensional coordinate positioning system 5d includes: a stable base 501, on which a first linear module 502 arranged along a first horizontal direction is fixed; a second linear module 503 arranged along a height direction is fixedly connected to the sliding end of the first linear module 502; a third linear module 504 arranged along a second horizontal direction is fixed to the sliding end of the second linear module 503; a mounting base 505 is fixed to the sliding end of the third linear module 504, and a high-frequency laser sheet light source 8 is configured and installed on the mounting base 505; through the above-mentioned series three-level linear module design, the high-frequency laser sheet light source 8 can move independently and precisely along the first horizontal direction, the height direction, and the second horizontal direction, so that the laser sheet light 11 emitted by it can accurately penetrate the wind tunnel window 12, and horizontally irradiate and cover the predetermined spanwise center test section of the wing model 10 from the side.

[0056] The three-dimensional coordinate positioning system 6 on the top of the tunnel is responsible for supporting and positioning the high-speed camera 7. It is located above the transparent glass cover 9 at the top of the wind tunnel test section 3.

[0057] To ensure stable suspension and high-rigidity movement within the large-span tunnel ceiling space, the tunnel ceiling three-dimensional coordinate positioning system 6 adopts a gantry-type symmetrical structure, specifically including: a fourth linear module 601 fixedly arranged along the first horizontal direction, and a linear guide rail 602 arranged parallel and symmetrically to it in the second horizontal direction. A horizontally placed connector 603 is installed between the sliding end of the fourth linear module 601 and the slider of the linear guide rail 602. When the motor of the fourth linear module 601 is driven, the sliding end drives the connector 603, and the other end slides synchronously along the linear guide rail 602, thereby driving the entire upper frame to move smoothly along the first horizontal direction. A fifth linear module 604 arranged along the second horizontal direction is fixed on the connector 603; a sixth linear module 605 arranged along the height direction is fixed on the sliding end of the fifth linear module 604; a camera gimbal 606 for holding the camera is arranged on the sliding part at the bottom of the sixth linear module 605, and the high-speed camera 7 is fixed on the camera gimbal 606.

[0058] In this way, the high-speed camera 7 gains the ability to precisely adjust its spatial position along the first horizontal direction, the second horizontal direction, and the height direction. Its imaging optical path can penetrate vertically downward through the transparent glass cover plate 9, align with the test section, and realize the standard Tr-PIV particle image acquisition optical path with the optical path perpendicular to the laser sheet light plane.

[0059] Specifically, the base 501 of the tunnel side three-dimensional coordinate positioning system 5 and the fourth linear module 601 and linear guide rail 602 of the tunnel top three-dimensional coordinate positioning system 6 are all installed with a gap between them and the tunnel wall of the wind tunnel test section 3 or with a flexible vibration isolation structure. That is, the installation platform base is physically isolated from the tunnel body, which can effectively prevent the high-frequency vibration of the tunnel body caused by the fan or airflow from being transmitted to the high-resolution optical testing system during wind tunnel operation, thereby significantly reducing the test uncertainty caused by such external disturbances.

[0060] Please see Figure 5 The demonstration showcased the complete interconnected state of the device in practical application: the steering control system, consisting of the steering control touchscreen 1 and the steering control cabinet 2, is connected to the power input module 18 and control input module 19 of the steering mechanism 4 via cables, providing power to the drive motor 20 and issuing control commands for steering speed and amplitude. The system supports manual / automatic mode switching, satisfying both static fixed rudder angle and dynamic oscillating rudder angle test scenarios.

[0061] This invention provides a method for conducting experiments using the above-mentioned device, the workflow and principle of which are as follows: The first step is to vertically install the wing-rudder model 10 and its integrated steering mechanism 4 on the center of the wind tunnel test section 3 using a support rod, and connect all the cables of the steering control system.

[0062] The second step is to determine the flow field test section as the spanwise center position of the rudder blade 23, and the normal direction of the section is determined as the vertical direction of the wind tunnel test section. Based on this, the flow field test system is arranged: the high-frequency laser sheet light source 8 is installed on the three-dimensional coordinate positioning system 5 on the side of the tunnel, and the high-speed camera 7 is installed on the three-dimensional coordinate positioning system 6 on the top of the tunnel, forming a structure of side illumination and top shooting.

[0063] The third step involves activating the flow field testing system by seeding tracer particles into the wind tunnel and observing real-time images from the high-speed camera 7. Subsequently, the linear modules on the three-dimensional coordinate positioning systems at the tunnel side and top are operated to precisely adjust the spatial coordinates of the high-speed camera 7 and the high-frequency laser sheet light source 8. The final state of adjustment is as follows: the plane of the laser sheet light 11, horizontally incident from the wind tunnel sidewall, completely coincides with the test section at the spanwise center of the rudder blade 23; the focusing plane of the high-speed camera 7, shooting vertically downwards from the tunnel top, coincides with the plane of the laser sheet light 11, and the camera's imaging optical axis is perpendicular to this plane. Based on this, a precision calibration target is placed at the test section for spatial scale calibration, completing the calibration of the entire Tr-PIV system.

[0064] The fourth step is to start the wind tunnel and wait for the airflow to stabilize; set the required dynamic steering parameters, such as steering rate and steering amplitude, through the steering control touch screen 1; the steering control system then controls the drive motor 20 to drive the rudder blade 23 to perform a predetermined reciprocating steering motion through the transmission track 21, rudder stick 14 and rudder sleeve 15 according to the instructions.

[0065] Fifth, after observing that the steering motion has been executed for more than three cycles and the flow field structure tends to be dynamically stable, a data acquisition command is issued through a synchronous trigger. The Tr-PIV system continuously emits two laser pulse sheet light sources in a very short time interval to illuminate the tracer particles in the same cross section of the flow field. The high-speed camera 7 simultaneously opens two exposures to record particle image pairs with time intervals. Then, the image pairs are processed by a cross-correlation algorithm to extract the two-dimensional velocity vector field in that transient state. This process is repeated, and the system continuously records time-history dynamic sequence images and velocity field data covering multiple steering cycles.

[0066] Thus, this invention achieves high spatiotemporal resolution and wide-area dynamic capture of unsteady flow fields around rudders in a wind tunnel environment under ship model steering conditions. Based on the collected time-history dynamic data, researchers can parametrically and statistically analyze the flow topology, the generation and evolution of large-scale separated vortices, and the mutual interference mechanism between vortex systems under steering conditions, thereby providing a detailed experimental data basis for the evaluation of ship maneuvering motion and flow stealth performance.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A test and measurement device for unsteady flow field under steering conditions of a ship model in a wind tunnel, characterized in that, include: The wind tunnel test section (3) has a height direction, a first horizontal direction and a second horizontal direction based on the structural definition of the wind tunnel test section (3); A wing-rudder model (10) is set inside the wind tunnel test section (3). The wing-rudder model (10) includes a stabilizing wing tip (22), a stabilizing wing body (24), and a rudder blade (23) that rotates relative to the stabilizing wing body (24). The steering mechanism (4) is connected to the rudder blade (23) for driving the rudder blade (23) to reciprocate around the rudder shaft at a predetermined steering speed and amplitude; A three-dimensional coordinate positioning system (6) for the top of the wind tunnel is set above the top surface of the wind tunnel test section (3); A three-dimensional coordinate positioning system (5) is installed on one side of the wind tunnel test section (3) in the second horizontal direction; A high-speed camera (7) is installed on the three-dimensional coordinate positioning system (6) at the top of the tunnel and is used to take images of tracer particles vertically downward from the top of the wind tunnel test section (3). A high-frequency laser sheet light source (8) is installed on the tunnel side three-dimensional coordinate positioning system (5) and is used to irradiate the wind tunnel test section (3) from the side to form a laser sheet light (11) covering the test section. Among them, the three-dimensional coordinate positioning system (6) on the top of the tunnel and the three-dimensional coordinate positioning system (5) on the side of the tunnel are respectively used to adjust the spatial positions of the high-speed camera (7) and the high-frequency laser sheet light source (8) in the first horizontal direction, the second horizontal direction and the height direction, so as to adapt to the test area that is dynamically changed by the rotation of the rudder blade (23); The stabilizing wing tip (22) of the wing-rudder model (10) is made of a fully transparent material to provide an unobstructed field of view for the high-speed camera (7); the surface of the stabilizing wing body (24) and the rudder blade (23) is provided with a matte paint layer; The top surface of the wind tunnel test section (3) is provided with a transparent glass cover plate (9), and the three-dimensional coordinate positioning system (6) of the tunnel top is located above the transparent glass cover plate (9); the wind tunnel test section (3) is provided with a wind tunnel porthole (12) on one side wall in the second horizontal direction, and the three-dimensional coordinate positioning system (5) of the tunnel side is located outside the wind tunnel porthole (12).

2. The test and measurement device for unsteady flow field of ship model steering state in a wind tunnel according to claim 1, characterized in that: The three-dimensional coordinate positioning system (5) for the tunnel side includes a base (501), a first linear module (502) disposed on the base (501) along a first horizontal direction, a second linear module (503) disposed along a height direction and fixed to the sliding end of the first linear module (502), and a third linear module (504) disposed along a second horizontal direction and fixed to the sliding end of the second linear module (503); a mounting base (505) is fixed on the sliding end of the third linear module (504), and the high-frequency laser chip light source (8) is disposed on the mounting base (505).

3. The test and measurement device for unsteady flow field of ship model steering state in a wind tunnel according to claim 1, characterized in that: The three-dimensional coordinate positioning system (6) at the top of the tunnel includes a fourth linear module (601) arranged along the first horizontal direction, a linear guide rail (602) symmetrically arranged with the fourth linear module (601) in the second horizontal direction, a connector (603) whose two ends are respectively engaged with the sliding end of the fourth linear module (601) and the linear guide rail (602) and driven by the fourth linear module (601) to move along the first horizontal direction, a fifth linear module (604) arranged along the second horizontal direction and fixed on the connector (603), and a sixth linear module (605) arranged along the height direction and fixed to the sliding end of the fifth linear module (604); the sliding end of the sixth linear module (605) is equipped with a camera gimbal (606) for mounting the high-speed camera (7).

4. The test and measurement device for unsteady flow field of ship model steering state in a wind tunnel according to claim 1, characterized in that: The steering mechanism (4) includes a drive motor (20), a rudder stalk (14) that is connected to the drive motor (20) in a transmission, and a rudder sleeve (15) that is fixedly sleeved on the outer periphery of the rudder stalk (14); the rudder sleeve (15) is fixedly connected to the rudder blade (23), the rudder stalk (14) extends from the bottom of the stabilizer body (24) into the rudder sleeve (15), and the drive motor (20) drives the rudder blade (23) to rotate through the rudder stalk (14) and the rudder sleeve (15).

5. The test and measurement device for unsteady flow field of ship model steering state in a wind tunnel according to claim 4, characterized in that: The steering mechanism (4) also includes a positioning pin (13), which passes through the end of the stabilizer (22) and is embedded in the rudder blade (23), and the center line of the positioning pin (13) coincides with the center line of the rudder shaft of the rudder blade (23).

6. The test and measurement device for unsteady flow field of ship model steering state in a wind tunnel according to claim 1, characterized in that: It also includes a steering control system, which is electrically connected to the steering mechanism (4) and is used to control the steering mechanism (4) to perform two steering motion modes: static fixed rudder angle or dynamic oscillating rudder angle.

7. A method for measuring the unsteady flow field during the steering state of a ship model in a wind tunnel, characterized in that, The application of the unsteady flow field test and measurement device for the steering state of a ship model in a wind tunnel as described in any one of claims 1 to 6 includes the following steps: Install the wing rudder model (10) and the steering mechanism (4), and connect the steering mechanism (4) to the steering control system; According to the normal direction of the flow field test section, the installation positions of the high-frequency laser sheet light source (8) and the high-speed camera (7) are arranged so that the high-frequency laser sheet light source (8) is installed on the side of the wind tunnel test section (3) and the laser sheet light (11) is used to horizontally irradiate and cover the test section from the side; the high-speed camera (7) is installed on the top of the wind tunnel test section (3) and the tracer particles are photographed with the optical path perpendicular to the test section. By using the three-dimensional coordinate positioning system (6) on the top of the tunnel and the three-dimensional coordinate positioning system (5) on the side of the tunnel, the spatial positions of the high-speed camera (7) and the high-frequency laser sheet light source (8) are finely adjusted so that the plane of the laser sheet light (11) coincides with the test section and the camera's shooting light path is perpendicular to the test section, thus completing the system debugging and calibration. Start the steering control system, set the steering rate and steering amplitude, and apply steering control commands to the steering mechanism (4) to drive the rudder blade (23) to perform steering motion; The test system is started, and dynamic data of the flow field time history are collected after the steering motion has been performed for a predetermined period.

8. The method for measuring the unsteady flow field of a ship model in a wind tunnel under steering conditions according to claim 7, characterized in that: When arranging the installation positions of the high-frequency laser sheet light source (8) and the high-speed camera (7), the mode of side-irradiation laser and vertical shooting by camera is adopted; the normal direction of the test section is the vertical direction of the wind tunnel test section (3), and the test section position is taken as the spanwise center position of the rudder blade (23).

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