Water tank PIV (particle image velocimetry) particle sowing device

Abstract

The invention relates to the technical field of coast and offshore engineering model tests, in particular to a water tank PIV particle sowing device. Wherein a flow channel is arranged in the water tank, the support is arranged in the water tank in a sliding mode, the first baffles are evenly arranged at intervals, one ends of the first baffles are rotationally connected to the support, the other ends of the first baffles abut against the bottom of the water tank, and the throwing pipes correspond to the first baffles one to one. A plurality of outlets are formed in the first baffle at intervals in the vertical direction, the throwing pipe communicates with the outlets and is used for throwing tracer particles, and the flow velocity measuring mechanism is arranged on the downstream of the rectifying mechanism. By arranging the first baffles and adjusting the angles of the first baffles, water flow can be smooth, and the stability of the water flow is improved; the throwing pipe is communicated with the vertically distributed outlets, so that the particles can be uniformly diffused in the water body along the vertical direction, and the uniformity and the concentration stability of the particles after throwing are improved.

Description

Technical Field

[0001] The invention relates to the technical field of coastal and offshore engineering model tests, and in particular to a water tank PIV particle spreading device. Background Art

[0002] Flume physical model tests are an important means of studying ports, coasts and offshore engineering. With the help of water flow flumes, researchers can conduct studies on water flow-structure interactions. Due to its non-invasive characteristics, particle image velocimetry is very popular in current flow field measurements. When using PIV to measure the two-dimensional flow field around a structure under the action of water flow, it is necessary to place tracer particles upstream of the flume. When the particles pass through the area to be tested with the water flow, the velocity vector of the local area of ​​the particles can be calculated by analyzing the displacement of each tracer particle in two adjacent frames, and finally the flow field of the area to be tested is obtained. The stability of the water flow in the flume, the uniformity of the tracer particles after placement, and the stability of the concentration are the key factors affecting the measurement effect of the PIV test.

[0003] However, in the prior art, in terms of water flow stability, the water flow created by pumping water upstream of the water tank often has large fluctuations and poor flow uniformity; in terms of tracer particles, experimenters mostly use manual or extraction pumping methods to release particles, and pour the pre-configured high-concentration particle solution directly into the water tank, which can easily lead to poor particle uniformity and concentration stability in the water tank.

[0004] Therefore, there is an urgent need for a water tank PIV particle spreading device to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a water tank PIV particle spreading device, which can improve the stability of water flow in the water tank, the uniformity of tracer particles after being released, and the stability of concentration.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A water trough PIV particle broadcasting device comprises: a water trough, a rectifying mechanism, a particle input mechanism and a flow velocity measuring mechanism, wherein a flow channel is arranged in the water trough, and the flow channel is extended along a first direction, the rectifying mechanism comprises a bracket and a plurality of first baffles, the bracket is slidably arranged in the water trough along the first direction, a plurality of first baffles are evenly spaced along a second direction, and one end of a plurality of first baffles are rotatably connected to the bracket, and the other ends of a plurality of first baffles are abutted against the bottom of the water trough to separate the flow channel into a plurality of branch flow channels, the particle input mechanism comprises a plurality of delivery pipes, a plurality of the delivery pipes are arranged in a one-to-one correspondence with a plurality of the first baffles, a plurality of outlets are arranged on the first baffles at intervals along a vertical direction, the delivery pipes are connected to the plurality of outlets, the delivery pipes are used to deliver tracer particles, the flow velocity measuring mechanism is arranged downstream of the rectifying mechanism, the flow velocity measuring mechanism is used to measure the water flow velocity, and the first direction is perpendicular to the second direction.

[0008] As a preferred technical solution of the above-mentioned water tank PIV particle spreading device, the rectification mechanism also includes a plurality of second baffles, and the plurality of second baffles are arranged one-to-one corresponding to the plurality of first baffles, one ends of the plurality of second baffles are evenly spaced and arranged on the bracket, and the first baffle is rotatably connected to the second baffle.

[0009] As an optimal technical solution for the above-mentioned water tank PIV particle spreading device, the rectification mechanism also includes a plurality of rotating shafts, and the plurality of rotating shafts are arranged in a one-to-one correspondence with the plurality of second baffles. The rotating shafts are rotatably connected to the second baffles, and the rotating shafts are fixedly connected to the first baffles.

[0010] As an optimal technical solution of the above-mentioned water tank PIV particle spreading device, the rectification mechanism also includes a plurality of driving members, and the plurality of driving members are arranged in a one-to-one correspondence with the plurality of rotating shafts. The driving members are transmission-connected with the rotating shafts, and the driving members can drive the rotating shafts to rotate.

[0011] As a preferred technical solution of the above-mentioned water tank PIV particle sowing device, the water tank PIV particle sowing device also includes two sliders, the two sliders are respectively arranged at both ends of the bracket, and the two sliders are respectively slidably connected to two opposite side walls of the water tank.

[0012] As an optimal technical solution of the above-mentioned water trough PIV particle sowing device, the water trough PIV particle sowing device also includes two slide rails, the two slide rails are respectively arranged on the two side walls of the water trough, the two slide rails are arranged in a one-to-one correspondence with the two sliders, and the sliders are slidably connected to the slide rails.

[0013] As an optimal technical solution of the above-mentioned water tank PIV particle sowing device, the water tank PIV particle sowing device also includes a particle preparation component, and the particle preparation component includes a mixing barrel, a propeller, a rotating rod and a main pipe. The mixing barrel is used to store the tracer particles, the rotating rod is rotatably arranged in the mixing barrel, the propeller is sleeved on the outer periphery of the rotating rod, and the main pipe connects the mixing barrel and the plurality of the delivery pipes.

[0014] As a preferred technical solution of the above-mentioned water tank PIV particle sowing device, the water tank PIV particle sowing device also includes a water pump, and the water pump is connected to the mixing barrel and the main pipe.

[0015] As an optimal technical solution for the above-mentioned water tank PIV particle spreading device, the flow velocity measuring mechanism includes a plurality of velocities meters, and the plurality of velocities meters are evenly spaced along the second direction downstream of the rectification mechanism, and the plurality of velocities meters are symmetrically distributed along the first direction.

[0016] As a preferred technical solution of the above-mentioned water tank PIV particle broadcasting device, the number of the velocities meters is an odd number, and the velocities meters are centrally symmetrically distributed along the first direction.

[0017] Beneficial effects of the present invention:

[0018] The present invention provides a water tank PIV particle spreading device. The device includes a water tank, a rectifying mechanism, a particle input mechanism and a flow rate measuring mechanism. A flow channel is arranged in the water tank, and the flow channel is extended along a first direction. The rectifying mechanism includes a bracket and a plurality of first baffles. The bracket is slidably arranged in the water tank along the first direction. The plurality of first baffles are evenly spaced along a second direction, and one end of the plurality of first baffles is rotatably connected to the bracket, and the other ends of the plurality of first baffles are against the bottom of the water tank to separate the flow channel into a plurality of branch flow channels. The particle input mechanism includes a plurality of delivery pipes, and the plurality of delivery pipes are arranged one by one corresponding to the plurality of first baffles. The first baffle is provided with a plurality of outlets at intervals along a vertical direction, and the delivery pipe is connected to the plurality of outlets, and the delivery pipe is used to deliver tracer particles. The flow rate measuring mechanism is arranged downstream of the rectifying mechanism, and the flow rate measuring mechanism is used to measure the water flow velocity. The first direction is perpendicular to the second direction. The device can make the water flow smooth and improve the stability of the water flow by arranging a plurality of first baffles and adjusting the angles of the first baffles; the delivery pipe is connected to the vertically distributed outlets, so that the particles can be evenly diffused in the water body along the vertical direction, so that the particles are evenly diffused in the water body, and the uniformity of the particles after delivery and the stability of the concentration are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of the structure of a water tank PIV particle spreading device provided in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a rectifier mechanism provided in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the structure of a particle input mechanism provided in an embodiment of the present invention.

[0023] In the figure:

[0024] 1. Water tank; 101. Flow channel; 2. Bracket; 3. First baffle; 4. Delivery pipe; 5. Flow velocity measuring mechanism; 51. Speed ​​meter; 6. Second baffle; 7. Rotating shaft; 8. Driving member; 9. Sliding block; 10. Slide rail; 11. Mixing barrel; 12. Propeller; 13. Rotating rod; 14. Main pipe. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0026] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0028] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0029] like Figures 1 to 3 As shown, the present invention provides a water tank PIV particle spreading device, which includes a water tank 1, a rectifying mechanism, a particle input mechanism and a flow rate measuring mechanism 5.

[0030] Specifically, a flow channel 101 is arranged in the water tank 1, and the flow channel 101 is extended along the first direction. The rectifying mechanism includes a bracket 2 and a plurality of first baffles 3. The bracket 2 is slidably arranged on the water tank 1 along the first direction. The plurality of first baffles 3 are evenly spaced along the second direction, and one end of the plurality of first baffles 3 is rotatably connected to the bracket 2, and the other ends of the plurality of first baffles 3 are abutted against the bottom of the water tank 1 to separate the flow channel 101 into a plurality of branch flow channels 101. The particle input mechanism includes a plurality of delivery tubes 4, and the plurality of delivery tubes 4 are arranged in a one-to-one correspondence with the plurality of first baffles 3. The first baffle 3 is provided with a plurality of outlets spaced along the vertical direction, and the delivery tube 4 is connected to the plurality of outlets, and the delivery tube 4 is used to deliver tracer particles. A flow velocity measuring mechanism 5 is arranged downstream of the rectifying mechanism, and the flow velocity measuring mechanism 5 is used to measure the water flow velocity. The first direction is perpendicular to the second direction. The device can make the water flow smooth and improve the stability of the water flow by setting a plurality of first baffles 3 and adjusting the angle of the first baffles 3; the delivery pipe 4 is connected to the vertically distributed outlets, which can make the particles evenly diffuse in the water body along the vertical direction, so that the particles are evenly diffused in the water body, and the uniformity and concentration stability of the particles after delivery are improved. It should be noted that the first direction is the length direction of the water tank 1, and the second direction is the width direction of the water tank 1.

[0031] Optionally, the rectifying mechanism further includes a plurality of second baffles 6, which are arranged one-to-one with the plurality of first baffles 3, one end of which is evenly spaced and arranged with the bracket 2, and the first baffle 3 is rotatably connected to the second baffle 6. Specifically, the first baffle 3 and the second baffle 6 are both thin plates of uniform thickness, and the first baffle 3 is rotated to adjust the cross-sectional area of ​​the water flow section, and at the same time, fine-tune the direction of the tracer particle delivery.

[0032] Further, the rectifying mechanism further includes a plurality of rotating shafts 7, which are arranged one by one with the plurality of second baffles 6, the rotating shafts 7 are rotatably connected to the second baffles 6, and the rotating shafts 7 are fixedly connected to the first baffle 3; the rectifying mechanism further includes a plurality of driving members 8, which are arranged one by one with the plurality of rotating shafts 7, the driving members 8 are transmission-connected with the rotating shafts 7, and the driving members 8 can drive the rotating shafts 7 to rotate. Specifically, the driving member 8 is a motor, and the motor can drive the first baffle 3 to rotate.

[0033] Optionally, the water tank PIV particle sowing device further includes two sliders 9, which are respectively arranged at the two ends of the bracket 2, and the two sliders 9 are respectively slidably connected to the two opposite side walls of the water tank 1; the water tank PIV particle sowing device further includes two slide rails 10, which are respectively arranged at the two side walls of the water tank 1, and the two slide rails 10 are arranged one-to-one with the two sliders 9, and the sliders 9 are slidably connected to the slide rails 10. Specifically, a plurality of second baffles 6 are arranged in parallel and spaced apart, and a plurality of second baffles 6 are all slidably arranged on the bracket 2, and the position and interval of each second baffle 6 along the width direction of the water tank 1 can be adjusted and fixed. By default, they are evenly spaced apart, and the other ends of the plurality of second baffles 6 are in direct contact with the bottom surface of the water tank 1 after the device is installed. The bracket 2 spans across the two ends of the width direction of the water tank 1 and is connected to the two sliders 9, so that the bracket 2 can be moved and fixed along the upstream and downstream length directions of the water tank 1.

[0034] Optionally, the water tank PIV particle sowing device also includes a particle preparation component, which includes a stirring barrel 11, a propeller 12, a rotating rod 13 and a main pipe 14. The stirring barrel 11 is used to store tracer particles. The rotating rod 13 is rotatably arranged in the stirring barrel 11. The propeller 12 is sleeved on the outer circumference of the rotating rod 13. The main pipe 14 connects the stirring barrel and a plurality of delivery pipes 4. The water tank PIV particle sowing device also includes a water pump, which connects the stirring barrel 11 and the main pipe 14. Specifically, the stirring barrel 11 is composed of a cylindrical acrylic outer wall and a metal cover plate, and is the main container for the production and storage of tracer particles. The propeller 12 is composed of four blades, which are fixed on the rotating rod 13 at the position of the central symmetry axis of the cylindrical barrel. The stirring barrel 11 has a hole at the lower end, which is connected to the main pipe 14 through a water pump. A flow rate controller is provided in the main pipe 14 to monitor the flow rate of the particle solution in the main pipe 14. Furthermore, the water pump is a variable frequency water pump, which can control the real-time change of particle concentration, achieve the matching of particle concentration and water flow velocity, and improve the measurement accuracy of the PIV test flow field.

[0035] Optionally, the flow velocity measuring mechanism 5 includes a plurality of velocities 51, which are evenly spaced and arranged downstream of the rectifying mechanism along the second direction, and are symmetrically distributed along the first direction; the number of velocities 51 is an odd number, and the velocities 51 are centrally symmetrically distributed along the first direction. Specifically, in this embodiment, the flow velocity measuring mechanism 5 is provided with three velocities 51, which are centrally symmetrical in the horizontal section direction, and have the same positions in the length direction and vertical direction of the water tank 1. The velocity measurement result is an average value over a period of time, which can observe the rectifying effect during the test, calibrate the flow velocity, and calibrate the particle pumping rate. For example, when the average flow velocity required for the test is 0.1 m / s, before the rough adjustment, the flow velocity measuring mechanism 5 is used to calibrate the parameters of the flow generator of the flume itself, and the bracket 2 is adjusted along the upstream and downstream directions of the flume 1. After the rectification effect is initially ensured, the flow generator parameters are determined, and then the rectification fine adjustment is performed, that is, the positions of the slider 9 and the second baffle 6 and the angle of the first baffle 3 are adjusted by the existing flow generator parameters to adjust the flume flow. Of course, in some other embodiments, the number of tachometers 51 is determined according to the actual situation. No further details are given here.

[0036] The water tank PIV particle spreading device provided by the present invention is used in conjunction with necessary equipment for flow field measurement such as a high-speed camera and a laser. The use process of the device is as follows:

[0037] First, turn on the water pump in the water tank 1 to create flow, adjust the front and rear positions of the rectifier through the slider 9, observe whether the average value of the speed meter 51 at the center position is stable, and ensure that the water flow is relatively stable when it reaches the front section of the test section. After fixing the slider 9, monitor the cross-sectional flow velocity distribution of different flow rate measurements, roughly adjust the position of the second baffle 6 on the bracket 2, and drive the first baffle 3 to swing as a whole or individually driven by the driving member 8 to adjust the specific section opening. With this arrangement, the final rectifier position of the rectifier can be found, and at the same time, the uniformity of the water flow velocity in the water tank 1 along the width direction can be adjusted according to the needs of the flow field, so as to achieve a uniform cross-section, or a water flow arrangement with low flow velocity at both ends of the water tank 1 and high flow velocity in the middle section;

[0038] Then, ensure that the mixing barrel 11 is clean, add the liquid and particles of the pre-determined mass into the mixing barrel 11 in turn, close the mixing barrel 11, turn on the propeller 12 through the electronic control system until it is fully mixed and stopped, and turn on the water pump in advance to pump a small amount of particle solution into the water tank 1, and observe the reflective effect of the particles in the water tank 1. At this time, the particles reach the first baffle 3 through the water pump and the delivery pipe 4. The first baffle 3 has vertically uniform outlets, and the solution leaks out through the reserved outlet of the delivery pipe 4. When the particles reach the laser section, the laser reflection effect is obvious and there is basically no local flickering, it can be determined that the mixing is basically uniform. According to the required particle concentration in the water tank 1, the pumping efficiency required by the particles can be calibrated in advance, and the particle preparation and pumping process can be controlled by the electronic control system. The concentration of particles in the water body of the water tank 1 can be adjusted by adjusting the pumping speed. This setting, on the one hand, reduces the influence of human factors on particle delivery, and on the other hand, it also improves the speed of test personnel in preparing the test.

[0039] In addition, the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A water tank PIV particle spreading device, characterized in that: include: A water tank (1), a rectifying mechanism, a particle input mechanism and a flow rate measuring mechanism (5), wherein a flow channel (101) is arranged in the water tank (1), and the flow channel (101) is extended along a first direction; the rectifying mechanism comprises a bracket (2) and a plurality of first baffles (3); the bracket (2) is slidably arranged on the water tank (1) along the first direction; the plurality of first baffles (3) are evenly spaced along a second direction; one end of the plurality of first baffles (3) are rotatably connected to the bracket (2), and the other ends of the plurality of first baffles (3) are connected to the bottom of the water tank (1). The flow channel (101) is offset from each other to separate the flow channel (101) into a plurality of branch flow channels (101); the particle input mechanism comprises a plurality of delivery tubes (4); the plurality of delivery tubes (4) are arranged in one-to-one correspondence with the plurality of first baffles (3); the first baffle (3) is provided with a plurality of outlets spaced apart in a vertical direction; the delivery tubes (4) are connected to the plurality of outlets; the delivery tubes (4) are used to deliver tracer particles; the flow velocity measuring mechanism (5) is arranged downstream of the rectifying mechanism; the flow velocity measuring mechanism (5) is used to measure the water flow velocity; the first direction is perpendicular to the second direction.

2. A water tank PIV particle spreading device according to claim 1, characterized in that: The rectifying mechanism further comprises a plurality of second baffles (6), the plurality of second baffles (6) being arranged in one-to-one correspondence with the plurality of first baffles (3), one end of the plurality of second baffles (6) being evenly spaced and arranged on the bracket (2), and the first baffles (3) being rotatably connected to the second baffles (6).

3. A water tank PIV particle spreading device according to claim 2, characterized in that: The rectifying mechanism further comprises a plurality of rotating shafts (7), the plurality of rotating shafts (7) being arranged in one-to-one correspondence with the plurality of second baffles (6), the rotating shafts (7) being rotatably connected to the second baffles (6), and the rotating shafts (7) being fixedly connected to the first baffles (3).

4. A water tank PIV particle spreading device according to claim 3, characterized in that: The rectifying mechanism further comprises a plurality of driving members (8), wherein the plurality of driving members (8) are arranged in a one-to-one correspondence with the plurality of rotating shafts (7), the driving members (8) are transmission-connected with the rotating shafts (7), and the driving members (8) can drive the rotating shafts (7) to rotate.

5. A water tank PIV particle spreading device according to claim 1, characterized in that: The water tank PIV particle sowing device further comprises two sliders (9), the two sliders (9) being respectively arranged at the two ends of the bracket (2), and the two sliders (9) being respectively slidably connected to two opposite side walls of the water tank (1).

6. A water tank PIV particle spreading device according to claim 5, characterized in that: The water tank PIV particle sowing device also includes two slide rails (10), the two slide rails (10) are respectively arranged on the two side walls of the water tank (1), the two slide rails (10) are arranged in a one-to-one correspondence with the two sliders (9), and the sliders (9) are slidably connected to the slide rails (10).

7. A water tank PIV particle spreading device according to claim 1, characterized in that: The water tank PIV particle broadcasting device also includes a particle preparation component, which includes a mixing barrel (11), a propeller (12), a rotating rod (13) and a main pipe (14). The mixing barrel (11) is used to store the tracer particles, the rotating rod (13) is rotatably arranged in the mixing barrel (11), the propeller (12) is sleeved on the outer periphery of the rotating rod (13), and the main pipe (14) connects the mixing barrel and the plurality of delivery pipes (4).

8. A water tank PIV particle spreading device according to claim 7, characterized in that: The water tank PIV particle sowing device also includes a water pump, and the water pump is connected to the mixing barrel (11) and the main pipe (14).

9. A water tank PIV particle spreading device according to any one of claims 1 to 8, characterized in that: The flow velocity measuring mechanism (5) comprises a plurality of velocities (51), wherein the plurality of velocities (51) are arranged at even intervals downstream of the rectifying mechanism along the second direction, and the plurality of velocities (51) are symmetrically distributed along the first direction.

10. A water tank PIV particle spreading device according to claim 9, characterized in that: The number of the speed meters (51) is an odd number, and the speed meters (51) are centrally symmetrically distributed along the first direction.

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