PIV test device and test method for ship model flow field in wind tunnel

Abstract

The invention relates to a ship model flow field PIV test device in a wind tunnel, which comprises a fixed base and a linear track, and is characterized in that the fixed base is arranged in a wind tunnel test section and is connected with a test section structure; the linear track is arranged on the fixed base; the front longitudinal sliding base and the rear longitudinal sliding base are arranged on the linear track; the front supporting rod is arranged on the front longitudinal sliding base; the rear supporting rod is arranged on the rear longitudinal sliding base through an arc guide rail and an arc sliding block. The test model is arranged on the front support rod and the rear support rod; the arc guide rail is arranged on the rear longitudinal sliding base, the arc sliding block is arranged at the bottom of the rear supporting rod, the rear supporting rod can move along the arc guide rail through the arc sliding block, the front supporting rod comprises a front large supporting rod and a front small supporting rod, an arc kidney-shaped hole is formed between the front large supporting rod and the front small supporting rod, and the front large supporting rod and the front small supporting rod can rotate relatively. According to the method, PIV calibration, different test section position changes and yaw angle changes can be quickly realized, and the model does not need to be disassembled when PIV is re-calibrated.

Description

Technical Field

[0001] The invention relates to the technical field of fluid mechanics test and testing, in particular to a PIV test device and a test method for a ship model flow field in a wind tunnel. Background Art

[0002] PIV particle image velocimetry is a method that uses multiple cameras to record the position of particles in the flow field and analyze the captured images to measure the flow velocity. The basic principle is to spread tracer particles in the flow field, use a pulsed laser light source to irradiate the required test section, record the particle image on the camera through two or more consecutive exposures, and then use algorithms such as cross-correlation to solve the velocity field. For stereoscopic PIV technology, two cameras are needed to observe the same flow field from two different directions, and then reconstruct the spatial displacement of the flow through the perspective principle, thereby obtaining the three components of the velocity vector that cannot be obtained by traditional planar PIV.

[0003] When conducting PIV tests on ship model flow fields in a wind tunnel, a calibration target is usually placed in the wind tunnel for calibration first to obtain the conversion relationship between pixel distance and physical distance. In the subsequent test process, the position and angle of the camera, laser polarization, etc. cannot be changed, that is, the optical path remains unchanged, otherwise recalibration is required; especially for SPIV tests, even the smallest changes can easily affect the test accuracy. Since the calibration position and the model position coincide, the PIV system needs to be calibrated first, and then the model is installed.

[0004] When existing test models need to be recalibrated, they need to be dismantled, recalibrated, and then reinstalled. For larger ship models, high-precision installation itself takes a lot of time, and it is even more difficult when testing multiple cross-section positions.

[0005] Therefore, we propose a PIV test device and test method for ship model flow field in a wind tunnel. Summary of the invention

[0006] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a PIV test device and test method for ship model flow field in a wind tunnel, which can quickly realize functions such as PIV calibration, position change of different test sections, yaw angle change, and there is no need to dismantle the model when recalibrating PIV.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A PIV test device for a ship model flow field in a wind tunnel, comprising:

[0009] A fixed base is arranged in the wind tunnel test section and connected to the test section structure;

[0010] A linear track, arranged on a fixed base;

[0011] The front longitudinal sliding base and the rear longitudinal sliding base are arranged on a linear track;

[0012] A front support rod, arranged on a front longitudinal sliding base;

[0013] The rear support rod is arranged on the rear longitudinal sliding base through the circular arc guide rail and the circular arc slider;

[0014] A test model, set on the front strut and the rear strut;

[0015] Among them, the arc guide rail is arranged on the rear longitudinal sliding base, the arc slider is arranged at the bottom of the rear support rod, the rear support rod can move along the arc guide rail through the arc slider, the front support rod includes a front large support rod and a front small support rod with an arc waist-shaped hole between them, and the front large support rod and the front small support rod can rotate relatively.

[0016] It is further characterized by:

[0017] The test model is provided with a front pre-embedded base and a rear pre-embedded base.

[0018] The length of the test model is L, the distance between the front and rear sections of the test section is l, and the length of the straight track and the fixed base is greater than L+l.

[0019] The rear longitudinal sliding base and the front longitudinal sliding base are both provided with a locking mechanism, and the locking mechanism is used to control whether the rear longitudinal sliding base and the front longitudinal sliding base can move.

[0020] The front longitudinal sliding base is provided with a front air guide cover, and the rear longitudinal sliding base is provided with a rear air guide cover.

[0021] The front air duct is divided into two parts, the lower part of the front air duct is integral, and the upper part of the front air duct is split; the rear air duct is divided into upper and lower parts, the lower part of the rear air duct is integral, and the upper part of the rear air duct is split.

[0022] The arc slider is provided with an adapter plate; the adapter plate is provided with a rear support rod connecting plate, the front longitudinal sliding base is provided with a front support rod connecting plate, the rear support rod connecting plate is provided with a rear large support rod, and the rear large support rod is provided with a rear small support rod.

[0023] The present invention also provides a PIV test method for a ship model flow field in a wind tunnel, comprising the following steps:

[0024] Installing fixed base and linear track in wind tunnel test section;

[0025] Install the calibration target and its supporting mechanism on the linear track so that the calibration plane coincides with the test section, complete the PIV system calibration, and keep the PIV test optical path fixed;

[0026] Move the calibration target support mechanism along the linear track to an area that does not affect the test model installation area, and remove the calibration target;

[0027] Install the front and rear support rods;

[0028] Install the test model, adjust the test model's attitude, and adjust the test model to the expected yaw angle;

[0029] Carry out a test run of the test system, and after confirming that the system is normal, remove the calibration target support mechanism;

[0030] The test plane of the test model coincides with the laser sheet light, completing the test of the test section;

[0031] Release the locking mechanism of the rear longitudinal sliding base and the front longitudinal sliding base, move the test model to the next test section, make the test section coincide with the laser sheet light, lock the locking mechanism of the rear longitudinal sliding base and the front longitudinal sliding base, and complete the PIV test of the test section; continue to move the test model to the next test section until all tests are completed.

[0032] When the PIV system needs to be recalibrated, move the test model to one end and recalibrate.

[0033] When the PIV system needs to be recalibrated, the test model can be recalibrated by adjusting it to a larger yaw angle to avoid the calibration target area.

[0034] The beneficial effects of the present invention are as follows:

[0035] The present invention has a compact and reasonable structure and is easy to operate. It adopts a movable slide rail model installation base, and can move the test model 17 along the central axis of the test section in test facilities such as wind tunnels and water tunnels to achieve rapid calibration and testing of SPIV flow field tests. The test device has a compact and reliable structure and is easy to operate. The test method used can quickly realize PIV testing of different longitudinal sections of the model without repeatedly calibrating the PIV system, thereby improving test efficiency.

[0036] At the same time, the present invention also has the following advantages:

[0037] (1) When the PIV system needs to be recalibrated, it is not necessary to dismantle the test model 17 and the supporting mechanism, thereby avoiding the time consumption caused by disassembling and reassembling the test model 17.

[0038] (2) The bottom of the rear support rod is equipped with an arc-shaped slide rail, which can flexibly adjust the model yaw angle within the range of ±16° while axially moving the test model 17, thereby realizing the variable drift angle flow field test in the upright state and the variable attack angle flow field test in the side-mounted state, which greatly enriches the test content of the model test. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a three-dimensional schematic diagram of the present invention.

[0040] Figure 2 for Figure 1 main view.

[0041] Figure 3 for Figure 1 Top view of the .

[0042] Figure 4 It is a schematic diagram of the test cross section of the present invention.

[0043] Figure 5 This is a schematic diagram of PIV calibration in which the calibration target of the present invention is placed on a mobile base.

[0044] Among them: 1. Fixed base; 2. Straight track; 3. Rear longitudinal sliding base; 4. Arc guide rail; 5. Adapter plate; 6. Rear support rod connecting plate; 7. Rear air deflector; 8. Rear large support rod; 9. Rear small support rod; 10. Rear embedded base; 11. Front longitudinal sliding base; 12. Front support rod connecting plate; 13. Front air deflector; 14. Front large support rod; 15. Front small support rod; 16. Front embedded base; 17. Test model; 18. Arc slider. DETAILED DESCRIPTION

[0045] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0046] like Figure 1-Figure 5 As shown, a PIV test device for a ship model flow field in a wind tunnel includes a fixed base 1, a linear track 2, a rear longitudinal sliding base 3, an arc guide rail 4, an adapter plate 5, a rear support rod connecting plate 6, a rear fairing 7, a rear large support rod 8, a rear small support rod 9, a rear embedded base 10, a front longitudinal sliding base 11, a front support rod connecting plate 12, a front fairing 13, a front large support rod 14, a front small support rod 15, a front embedded base 16, a test model 17 and an arc slider 18.

[0047] The fixed base 1 is arranged in the wind tunnel test section and connected to the test section structure, and the fixed base 1 includes two longitudinal beams, a plurality of cross beams and a front deflector. The linear track 2 is installed on the fixed base 1.

[0048] In one embodiment, the length of the fixed base 1 and the linear track 2 is determined according to the length of the test model 17, the front-to-back distance of the test section, and the PIV layout position. When the length of the test model 17 is set to L and the distance between the front and rear sections of the test section is set to l, the length of the linear track 2 and the fixed base 1 is greater than L+l.

[0049] The rear longitudinal sliding base 3 is installed on the linear track 2. The rear longitudinal sliding base 3 includes a connecting plate, a locking structure and four sliders. The connecting plate is arranged on the slider. The locking mechanism can lock the slider. The slider can move forward and backward along the linear track 2, thereby driving the connecting plate to move.

[0050] The circular arc guide rail 4 is installed on the rear longitudinal sliding base 3 , and the circular arc guide rail 4 is matched with an arc slider 18 , and the circular arc slider 18 is provided with an adapter plate 5 ; and the adapter plate 5 is provided with a rear support rod connecting plate 6 .

[0051] In one embodiment, the front longitudinal sliding base 11 and the rear longitudinal sliding base 3 have the same structure.

[0052] The front longitudinal sliding base 11 is installed on the linear track 2 , and a front support rod connecting plate 12 is provided on the front longitudinal sliding base 11 .

[0053] The rear large strut 8 is arranged on the rear strut connecting plate 6, the rear small strut 9 is arranged on the rear large strut 8, the front large strut 14 is arranged on the front strut connecting plate 12, the front small strut 15 is arranged on the front large strut 14, the front large strut 14 is connected to the front strut connecting plate 12, and the rear large strut 8 is connected to the rear strut connecting plate 6.

[0054] In one embodiment, the front fairing 13 and the rear fairing 7 are both hollow skin structures.

[0055] The front air deflector 13 is arranged on the front longitudinal sliding base 11, and the rear air deflector 7 is arranged on the rear longitudinal sliding base 3. The front air deflector 13 is divided into two parts, the lower part of the front air deflector 13 is integral, and the upper part of the front air deflector 13 is split. The rear air deflector 7 is divided into upper and lower parts, the lower part of the rear air deflector 7 is integral, and the upper part of the rear air deflector 7 is split, which is convenient for disassembly and assembly.

[0056] The front small support rod 15 and the rear small support rod 9 can be changed to different lengths to appropriately adjust the model height; when the lengths of the front small support rod 15 and the rear small support rod 9 become shorter, the upper parts of the front air guide cover 13 and the rear air guide cover 7 can be removed.

[0057] The front support rod comprises a front large support rod 14 and a front small support rod 15 , and the rear support rod comprises a rear large support rod 8 and a rear small support rod 9 .

[0058] The front embedded base 16 and the rear embedded base 10 are respectively arranged in the test model 17, and the test model 17 is installed on the rear small support rod 9 and the front small support rod 15.

[0059] When the test model 17 needs to be adjusted, the locking mechanism of the front longitudinal sliding base 11 and the rear longitudinal sliding base 3 is loosened, and the test model 17 is driven to move forward and backward by pushing the front large support rod 14, the rear large support rod 8, the front air deflector 13, and the rear air deflector 7, thereby adjusting the front and rear position of the test model 17.

[0060] When the yaw angle of the test model 17 needs to be adjusted, the test model 17 rotates around the center of the front support rod as a whole. The front support rod rotates through the arc-shaped waist-shaped hole between the front large support rod 14 and the front small support rod 15, and the rear support rod rotates through the arc guide rail 4 and the arc slider 18. When adjusting the yaw angle, loosen the screws between the front large support rod 14 and the front small support rod 15, loosen the locking mechanism of the arc slider 18, and then adjust the yaw angle of the test model 17 so that the test model 17 rotates around the center of the front support. When the predetermined yaw angle is reached, lock the screws.

[0061] When adjusting the yaw angle, it is necessary to loosen the screws between the front large support rod 14 and the front small support rod 15, and loosen the locking mechanism of the arc slider 18, and then adjust the yaw angle of the model so that the model as a whole rotates around the center of the front support rod. When the predetermined yaw angle is reached, tighten the nuts between the front large support rod 14 and the front small support rod 15 and the locking mechanism of the arc slider 18.

[0062] By adjusting the test model 17 to be flush with the wind tunnel axis, the fixed base 1, the linear track 2, the rear longitudinal sliding base 3, the arc guide rail 4, the arc slider 18, the adapter plate 5, the rear support rod connecting plate 6, the front longitudinal sliding base 11, the front support rod connecting plate 12, etc. can form an overall frame structure, which is convenient for overall lifting without reassembly, or only the fixed base 1, the linear track 2, the rear longitudinal sliding base 3, the front longitudinal sliding base 11 and other components can be retained to form an overall frame structure.

[0063] The overall frame structure can be leveled once in the wind tunnel, and the height of the lifting nut can be fixed to improve the efficiency of the next installation.

[0064] A PIV test device and test method for a ship model flow field in a wind tunnel, comprising the following steps:

[0065] Installing a fixed base 1 and a linear track 2 in a wind tunnel test section;

[0066] Install the calibration target and its supporting mechanism on the linear track 2 so that the calibration plane coincides with the test section, complete the PIV system calibration, and keep the PIV test optical path fixed;

[0067] Move the calibration target support mechanism along the linear track 2 to an area where the test model 17 is not affected, and remove the calibration target;

[0068] Install the front and rear support rods;

[0069] Install the test model 17, adjust the attitude of the test model 17, and adjust the test model 17 to the expected yaw angle;

[0070] Carry out a test run of the test system, and after confirming that the system is normal, remove the calibration target support mechanism;

[0071] The test plane of the test model 17 coincides with the laser sheet light, completing the test of the test section;

[0072] Release the locking mechanism of the rear longitudinal sliding base 3 and the front longitudinal sliding base 11, move the test model 17 to the next test section, make the test section coincide with the laser sheet light, lock the locking mechanism of the rear longitudinal sliding base 3 and the front longitudinal sliding base 11, and complete the PIV test of the test section; continue to move the test model 17 to the next test section until all tests are completed.

[0073] When the PIV system needs to be recalibrated, recalibration can be performed by simply moving the test model 17 to one end or adjusting the test model 17 to a larger yaw angle to avoid the calibration target area.

[0074] The present invention abandons the traditional bottom fixed support rod installation mode and adopts a movable slide rail model installation base, which can move the test model 17 along the central axis of the test section in test facilities such as wind tunnels and water tunnels to achieve rapid calibration and testing of SPIV flow field tests. The test device has a compact structure, is reliable, and is easy to operate. The test method used can quickly realize PIV testing of different longitudinal sections of the model without repeatedly calibrating the PIV system, thereby improving test efficiency.

[0075] The present invention makes it unnecessary to dismantle the test model 17 and the supporting mechanism when the PIV system needs to be recalibrated, thereby avoiding the time consumption caused by disassembling and reassembling the test model 17;

[0076] The bottom of the rear support rod of the present invention is equipped with an arc-shaped slide rail. While axially moving the test model 17, the model yaw angle can be flexibly adjusted within the range of ±16°, thereby realizing variable drift angle flow field test in the upright state of the model and variable attack angle flow field test in the side-mounted state, which greatly enriches the test content of the model test.

[0077] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A PIV test device for ship model flow field in a wind tunnel, characterized in that: include: A fixed base (1) is arranged in the wind tunnel test section and connected to the test section structure; A linear track (2) is arranged on a fixed base (1); A front longitudinal sliding base (11) and a rear longitudinal sliding base (3) are arranged on the linear track (2); A front support rod, arranged on a front longitudinal sliding base (11); The rear support rod is arranged on the rear longitudinal sliding base (3) through an arc guide rail (4) and an arc slide block (18); A test model (17) is arranged on the front support rod and the rear support rod; The circular arc guide rail (4) is arranged on the rear longitudinal sliding base (3), the circular arc slider (18) is arranged at the bottom of the rear support rod, the rear support rod can move along the circular arc guide rail (4) through the circular arc slider (18), the front support rod includes a front large support rod (14) and a front small support rod (15), and there is an arc waist-shaped hole between them, and the front large support rod (14) and the front small support rod (15) can rotate relatively.

2. A PIV test device for a ship model flow field in a wind tunnel as claimed in claim 1, characterized in that: The test model (17) is provided with a front pre-embedded base (16) and a rear pre-embedded base (10).

3. A PIV test device for a ship model flow field in a wind tunnel as claimed in claim 1, characterized in that: The length of the test model (17) is L, the distance between the front and rear sections of the test section is l, and the length of the straight track (2) and the fixed base (1) is greater than L+l.

4. A PIV test device for a ship model flow field in a wind tunnel as claimed in claim 3, characterized in that: The rear longitudinal sliding base (3) and the front longitudinal sliding base (11) are both provided with a locking mechanism, and the locking mechanism is used to control whether the rear longitudinal sliding base (3) and the front longitudinal sliding base (11) can move.

5. A PIV test device for a ship model flow field in a wind tunnel as claimed in claim 1, characterized in that: The front longitudinal sliding base (11) is provided with a front air guide cover (13), and the rear longitudinal sliding base (3) is provided with a rear air guide cover (7).

6. A PIV test device for a ship model flow field in a wind tunnel as claimed in claim 5, characterized in that: The front air guide cover (13) is divided into two parts, the lower part of the front air guide cover (13) is integral, and the upper part of the front air guide cover (13) is split; the rear air guide cover (7) is divided into upper and lower parts, the lower part of the rear air guide cover (7) is integral, and the upper part of the rear air guide cover (7) is split.

7. A PIV test device for a ship model flow field in a wind tunnel as claimed in claim 6, characterized in that: The arc slider (18) is provided with an adapter plate (5); the adapter plate (5) is provided with a rear support rod connecting plate (6); the front longitudinal sliding base (11) is provided with a front support rod connecting plate (12); the rear support rod connecting plate (6) is provided with a rear large support rod (8); and the rear large support rod (8) is provided with a rear small support rod (9).

8. A method for PIV testing of a ship model flow field in a wind tunnel, using a PIV testing device for a ship model flow field in a wind tunnel as claimed in any one of claims 1 to 6, characterized in that: The steps include: Installing a fixed base (1) and a linear track (2) in a wind tunnel test section; Installing a calibration target and its supporting mechanism on the linear track (2) so that the calibration plane coincides with the test section, completing the PIV system calibration, and keeping the PIV test optical path fixed; Move the calibration target support mechanism along the linear track (2) to an area where the test model (17) is not affected for installation, and remove the calibration target; Install the front and rear support rods; Installing the test model (17), adjusting the attitude of the test model (17), and adjusting the test model (17) to a desired yaw angle; Carry out a test run of the test system, and after confirming that the system is normal, remove the calibration target support mechanism; The test plane of the test model (17) coincides with the laser sheet light, completing the test of the test section; The locking mechanisms of the rear longitudinal sliding base (3) and the front longitudinal sliding base (11) are released, and the test model (17) is moved to the next test section so that the test section coincides with the laser sheet light. The locking mechanisms of the rear longitudinal sliding base (3) and the front longitudinal sliding base (11) are locked to complete the PIV test of the test section. The test model (17) is continuously moved to the next test section until all tests are completed.

9. A PIV test method for a ship model flow field in a wind tunnel as claimed in claim 8, characterized in that: When the PIV system needs to be recalibrated, the test model (17) is moved to one end and recalibrated.

10. A PIV test method for a ship model flow field in a wind tunnel as claimed in claim 8, characterized in that: When the PIV system needs to be recalibrated, the test model (17) is adjusted to a larger yaw angle to avoid the calibration target area, so that recalibration can be performed.

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