Solid tracer particle generator and flow field measurement device

Abstract

The present invention relates to a solid tracer particle generator, which includes a connecting flow channel and a combustion rack. A hollow combustion cavity is formed inside the connecting flow channel, and the combustion cavity can be connected in series to the experimental flow channel, thereby allowing the experimental fluid in the experimental flow channel to flow through the combustion cavity. The combustion rack is arranged in the combustion cavity, and the combustion rack can carry fuel. The tracer particles generated after the fuel is ignited can be mixed with the experimental fluid in the experimental flow channel and move with the experimental fluid. The present invention also relates to a flow field measurement device including the above-mentioned solid tracer particle generator. With the above-mentioned solid tracer particle generator and flow field measurement device, the entire process of solid tracer particle generation is completed in the experimental flow channel. During the experiment, the fuel can burn with the air in the experimental flow channel to generate solid tracer particles, and no additional gas flow is required, which is convenient for controlling the flow of the experimental fluid and ensures the solid tracer particles' ability to follow the fluid.

Description

Technical Field

[0001] The invention relates to the technical field of flow field detection, and in particular to a solid tracer particle generator and a flow field measuring device. Background Art

[0002] Particle image velocimetry (PIV) is a non-contact laser optical measurement technology that can be used to study and measure fluid motion processes such as flow, turbulence, spray atomization and combustion. It can perform relatively accurate flow velocity measurements without contacting the flow field. The premise for accurate flow field measurement by particle image velocimetry is the generation of tracer particles. A general tracer particle generator generates tracer particles outside the flow channel, and then adds the tracer particles to the flow channel by pumping. In the process of pumping tracer particles into the flow channel, a large gas pressure is generally required, which will seriously affect the fluid flow in the flow channel and make the fluid flow difficult to control; and the speed of the pumped tracer particles is also difficult to match the flow velocity of the original fluid, and the tracer particles have poor followability to the fluid. Interference with the fluid flow in the flow channel and the poor followability of the tracer particles to the fluid will result in low measurement accuracy of the flow field. Summary of the invention

[0003] Based on this, it is necessary to provide a solid tracer particle generator and a flow field measurement device with higher flow field measurement accuracy to address the problem of low flow field measurement accuracy of existing tracer particle generators due to pumping in tracer particles.

[0004] A solid tracer particle generator, comprising:

[0005] A connecting flow channel is formed with a hollow combustion cavity inside, and the combustion cavity can be connected in series to the experimental flow channel, thereby allowing the experimental fluid in the experimental flow channel to flow through the combustion cavity;

[0006] The combustion rack is arranged in the combustion chamber, and the combustion rack can carry fuel. The tracer particles generated after the fuel is ignited can be mixed with the experimental fluid in the experimental flow channel and move with the experimental fluid.

[0007] In one embodiment, the combustion rack includes multiple layers of combustion trays, and the multiple layers of combustion trays are arranged in the combustion chamber at intervals along the vertical direction, and the multiple layers of combustion trays can carry fuel respectively.

[0008] In one of the embodiments, the multiple layers of combustion trays are arranged in parallel, and the direction in which the multiple layers of combustion trays are spaced apart is perpendicular to the flow direction of the experimental fluid in the combustion chamber.

[0009] In one of the embodiments, the connecting flow channel includes a flow stabilizing portion, which is disposed in the combustion chamber and is used to slow down the flow rate of the experimental fluid flowing through the combustion tray.

[0010] In one of the embodiments, the flow stabilizing portion includes a plurality of layers of flow stabilizing grids, which are arranged in the combustion chamber at intervals along the vertical direction, and each layer of the flow stabilizing grid is located at an opening of a layer of the combustion tray.

[0011] In one embodiment, the connecting flow channel includes a combustion section, an inlet end and an outlet end, a hollow combustion chamber is formed inside the combustion section, the inlet end is arranged upstream of the combustion section along the flow direction of the experimental fluid, and the outlet end is arranged downstream of the combustion section along the flow direction of the experimental fluid, and the inlet end and the outlet end are respectively detachably fixedly connected to the experimental flow channel.

[0012] In one of the embodiments, the inlet end includes an inlet flange, and the outlet end includes an outlet flange. The inlet flange and the outlet flange can be detachably fixedly connected to the experimental flow channel respectively, so that the combustion chamber can be connected in series to the experimental flow channel.

[0013] In one of the embodiments, the connection direction of the inlet end, the combustion section and the outlet end on the connecting flow channel is a straight line, a curve or a broken line.

[0014] In one embodiment, the solid tracer particle generator further includes an igniter, which is disposed on the combustion rack and is used to ignite fuel on the combustion rack.

[0015] In one embodiment, the solid tracer particle generator also includes a push-pull frame, and a push-pull port is also provided on the connecting flow channel, the push-pull port is connected to the combustion chamber, the push-pull frame is detachably arranged at the push-pull port, and the push-pull frame is fixedly connected to the combustion frame; when the push-pull frame is installed at the push-pull port, the combustion frame is pushed into the combustion chamber, and when the push-pull frame is away from the push-pull port, the combustion frame is pulled out of the combustion chamber.

[0016] In one of the embodiments, the push-pull frame pushes the combustion frame into the combustion chamber along a horizontal direction, or the push-pull frame pulls the combustion frame out of the combustion chamber along a horizontal direction.

[0017] In one of the embodiments, a push-pull flange is formed at the push-pull opening, and the push-pull frame includes a push-pull panel, and the push-pull panel is detachably fixedly connected to the push-pull flange in a threaded connection manner.

[0018] In one embodiment, the combustion rack includes multiple layers of combustion trays, which are arranged in the combustion chamber at intervals along the vertical direction, and the multiple layers of combustion trays can carry fuel respectively; the connecting flow channel also includes a positioning plate, which is arranged at the bottom of the combustion chamber, and when the push-pull rack drives the combustion rack to enter or leave the combustion chamber, one layer of the combustion tray slides and fits with the upper surface of the positioning plate.

[0019] In one of the embodiments, when the push-pull frame drives the combustion frame to enter or leave the combustion chamber, the combustion tray at the bottom layer slides and fits with the upper surface of the positioning plate.

[0020] A flow field measuring device is used to measure the flow field distribution of a fluid. The flow field measuring device comprises an experimental flow channel and a solid tracer particle generator as described in any one of the above schemes. The solid tracer particle generator is connected in series to the flow channel.

[0021] The above-mentioned solid tracer particle generator and flow field measurement device, the solid tracer particle generator is embedded in the experimental flow channel, and the entire process of solid tracer particle generation is completed in the experimental flow channel. During the experiment, the fuel can burn with the air in the experimental flow channel to produce solid tracer particles, and no additional gas flow is required. The solid tracer particles are generated in the experimental flow channel, and no additional pumping steps are required, which effectively avoids the influence of the pumped gas with a higher pressure on the fluid flow in the experimental flow channel, and facilitates the control of the experimental fluid flow. In addition, the solid tracer particles are generated in the experimental flow channel, and the generated solid tracer particles directly enter the experimental fluid and are only driven by the experimental fluid, which ensures the solid tracer particles' ability to follow the fluid. The above-mentioned solid tracer particle generator and flow field measurement device have high measurement accuracy for the flow field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a solid tracer particle generator provided in one embodiment of the present invention;

[0023] Figure 2 A schematic diagram of a connecting flow channel structure provided in one embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the assembly relationship between a combustion rack and a push-pull rack provided in one embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the assembly relationship of a combustion frame, a push-pull frame, a flow stabilizing grid and a positioning plate provided in one embodiment of the present invention;

[0026] Figure 5 A schematic diagram of a flow stabilizing grid structure provided by an embodiment of the present invention;

[0027] Figure 6 A schematic diagram of the concentration of solid tracer particles in an experimental flow channel provided in one embodiment of the present invention;

[0028] Figure 7 A schematic diagram of the velocity of solid tracer particles in an experimental flow channel provided by one embodiment of the present invention.

[0029] Among them: 10, solid tracer particle generator; 100, connecting flow channel; 110, combustion section; 111, combustion chamber; 120, inlet flange; 130, outlet flange; 140, flow stabilizing grid; 150, push-pull flange; 160, positioning plate; 200, combustion rack; 210, combustion tray; 300, push-pull rack; 310, push-pull panel; 320, push-pull handle. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0036] The present invention relates to a tracer particle generator, specifically a flow channel embedded solid tracer particle generator suitable for PIV flow display measurement, which provides stable solid tracer particles with good followability for fluid mechanics experimental research related to aerospace, energy power, and building environment. The use of an experimental flow channel embedded tracer particle generation method is one of the effective ways to solve the problems of accurate control of experimental gas flow, uniformity of tracer particles, and poor followability.

[0037] like Figure 1-3As shown, an embodiment of the present invention provides a solid tracer particle generator 10, including a connecting flow channel 100 and a combustion rack 200. The connecting flow channel 100 is used to communicate with the experimental flow channel, and the connecting flow channel 100 is connected in series to the experimental flow channel. The combustion rack 200 is installed in the experimental flow channel to support the fuel to be burned. Specifically, a hollow combustion chamber 111 is formed inside the connecting flow channel 100, and the combustion chamber 111 can be connected in series to the experimental flow channel, thereby allowing the experimental fluid in the experimental flow channel to flow through the combustion chamber 111. The combustion rack 200 is disposed in the combustion chamber 111, and the combustion rack 200 can carry fuel. The tracer particles generated after the fuel is ignited can mix with the experimental fluid in the experimental flow channel and move with the experimental fluid. It can be understood that the connection between the connecting flow channel 100 and the experimental flow channel is a detachable fixed connection (such as threaded connection, clamping, etc.) or an irremovable fixed connection (such as welding, etc.); even the connecting flow channel 100 and the experimental flow channel can be integrated, in which case a certain section of the experimental flow channel serves as the connecting flow channel 100. Correspondingly, the solid tracer particle generator 10 provided in this embodiment can be disposable or reusable. This embodiment does not limit the specific connection relationship between the solid tracer particle generator 10 and the experimental flow channel.

[0038] The above-mentioned solid tracer particle generator 10 is embedded in the experimental flow channel. The entire process of solid tracer particle generation is completed in the experimental flow channel. During the experiment, the fuel can burn with the air in the experimental flow channel to produce solid tracer particles without the need for additional gas flow. The solid tracer particles are generated in the experimental flow channel without the need for additional pumping steps, which effectively avoids the influence of the pumped gas with a higher pressure on the fluid flow in the experimental flow channel, and facilitates the control of the experimental fluid flow. In addition, the solid tracer particles are generated in the experimental flow channel, and the generated solid tracer particles directly enter the experimental fluid and are only driven by the experimental fluid, which ensures the solid tracer particles' ability to follow the fluid. The above-mentioned solid tracer particle generator 10 and the flow field measurement device have high measurement accuracy for the flow field.

[0039] The uniform mixing of solid tracer particles and experimental fluid and their synchronous tracking are key steps in flow field measurement. Figure 1-4As shown, in one embodiment of the present invention, the combustion rack 200 includes a multi-layer combustion tray 210, which is arranged in a vertical direction in the combustion chamber 111, and the multi-layer combustion tray 210 can carry fuels respectively. The multi-layer combustion tray 210 carries fuels that can produce solid tracer particles respectively. When the solid tracer particles are produced in a combustion manner, they are distributed in a vertical direction, which is conducive to the solid tracer particles being fully mixed with the experimental fluid in the entire experimental flow channel. Further, the multi-layer combustion tray 210 is arranged in parallel, and the direction in which the multi-layer combustion tray 210 is arranged in a spaced manner is perpendicular to the flow direction of the experimental fluid in the combustion chamber 111. The parallel arrangement of the tray makes the distribution of the solid tracer particles produced by the fuel more uniform in space. And the direction in which the multi-layer combustion tray 210 is arranged in a spaced manner is perpendicular to the flow direction of the experimental fluid in the combustion chamber 111, and then the fuel-bearing surface of the combustion tray 210 is parallel to the flow direction of the experimental fluid, which can minimize the resistance caused by the combustion tray 210 to the flow of the experimental fluid. The number of layers of the combustion tray 210 can be adapted according to the experimental flow channel size and the concentration requirements of the solid tracer particles.

[0040] Optionally, the multi-layer combustion trays 210 are fixed to the inner wall of the combustion chamber 111 or supported by a tray frame. The multi-layer combustion trays 210 can also be designed to be distributed at equal intervals or at non-equal intervals according to the actual working conditions of the experimental fluid. Figure 1-4 As shown, as an achievable method, the combustion rack 200 includes five layers of combustion trays 210, and the five layers of combustion trays 210 are evenly spaced in the vertical direction, and the five layers of combustion trays 210 are supported by tray brackets. Specifically, the combustion tray 210 includes a bottom plate and a rib formed by bending the bottom plate upward along the outer periphery, and such a combustion tray 210 is semi-closed. During a single flow field measurement, the amount of fuel placed on each combustion tray 210 can be set according to the measurement requirements. For the convenience of further explanation, the vertical direction in which the multiple layers of combustion trays 210 are spaced apart is defined as the Z direction in the figure, the flow direction of the experimental fluid is defined as the horizontal longitudinal direction (the X direction in the figure), and the direction perpendicular to the vertical direction and the horizontal longitudinal direction is defined as the horizontal transverse direction (the Y direction in the figure).

[0041] The experimental fluid in the experimental flow channel and the connecting flow channel 100 flows through the combustion tray 210 at a flow rate within a set range. The fuel in the combustion tray 210 contacts the gas in the experimental fluid and burns. The stable combustion of the fuel is the key to producing solid tracer particles of uniform size and uniform concentration. In one embodiment of the present invention, the connecting flow channel 100 includes a flow stabilizing portion, which is arranged in the combustion chamber 111. The flow stabilizing portion is used to slow down the flow rate of the experimental fluid flowing through the combustion tray 210, and provide a suitable airflow for uniform and stable combustion of the fuel. As a feasible method, such as Figure 2-5 As shown, the flow stabilizing portion includes multiple layers of flow stabilizing grids 140, which are arranged in the combustion chamber 111 at intervals along the vertical direction, and each layer of flow stabilizing grids 140 is respectively located at the opening of a layer of combustion tray 210. In other embodiments, the flow stabilizing portion can also be a layer of high temperature resistant mesh covering the opening of the combustion tray 210.

[0042] There are many air holes on the flow stabilizing grid 140. When the experimental fluid flowing along the horizontal longitudinal direction (X direction) flows through the flow stabilizing grid 140, it can move downward in the vertical direction (Z direction) through the air holes and then contact the fuel. Since the flow direction of the experimental fluid is mainly horizontal and longitudinal (X direction), the flow rate of the experimental fluid passing through the air holes in the vertical direction (Z direction) is relatively low, which can allow the fuel to be burned evenly, stably and fully, thereby producing uniform tracer particles. In addition, the solid tracer particles produced by combustion can be entrained from the air holes of the flow stabilizing grid 140 into the mainstream of the experimental fluid by mainstream entrainment, and then the solid tracer particles are dispersed in the entire experimental flow channel driven by the experimental fluid, so that the solid tracer particles can stably follow the experimental fluid. Optionally, similar to the fixing method of the combustion tray 210, the multi-layer flow stabilizing grid 140 is respectively fixed on the inner wall of the combustion chamber 111 or supported by a grid bracket, so as to realize the spaced distribution of the multi-layer flow stabilizing grid 140 in the vertical direction, and correspond to the multi-layer combustion tray 210 one by one. In other embodiments of the present invention, the flow stabilizer grid 140 and the combustion tray 210 may be fixed together to form a whole.

[0043] In one embodiment of the present invention, the solid tracer particle generator 10 is detachably fixedly connected to and communicates with the experimental flow channel. Figure 1-3As shown, specifically, the connecting flow channel 100 includes a combustion section 110, an inlet end and an outlet end, a hollow combustion chamber 111 is formed inside the combustion section 110, the inlet end is arranged upstream of the combustion section 110 along the flow direction of the experimental fluid, and the outlet end is arranged downstream of the combustion section 110 along the flow direction of the experimental fluid, and the inlet end and the outlet end are respectively detachably fixedly connected to the experimental flow channel. Optionally, the inlet end and the outlet end of the solid tracer particle generator 10 are respectively connected to the experimental flow channel in the same or different manners and are equipped with necessary sealing measures, such as threaded connection, clamping, etc. As a feasible method, the inlet end includes an inlet flange 120, and the outlet end includes an outlet flange 130. The inlet flange 120 and the outlet flange 130 can be detachably fixedly connected to the experimental flow channel by bolts or screws, so that the combustion chamber 111 can be connected in series to the experimental flow channel. It can be understood that the part where the experimental flow channel is connected to the inlet flange 120 and the outlet flange 130 is also provided with a corresponding connecting flange. The flange connection method can not only ensure the connectivity between the solid tracer particle generator 10 and the experimental flow channel, but also facilitate the installation and maintenance of the entire flow field measurement device. The solid tracer particle generator 10 can be disassembled and assembled using bolts when necessary.

[0044] like Figure 1-3 As shown, in the above-mentioned embodiments, the direction of the line connecting the inlet end, the combustion section 110 and the outlet end of the connecting flow channel 100 is a straight line, which can minimize the flow resistance caused by the connecting flow channel 100 to the experimental fluid and ensure that the solid tracer particles produced by the combustion can be quickly carried away by the experimental fluid. In other embodiments, the direction of the line connecting the inlet end, the combustion section 110 and the outlet end of the connecting flow channel 100 is a curve or a broken line, as long as the solid tracer particle generator 10 is adapted to the actual working conditions.

[0045] In the above-mentioned embodiments, the combustion rack 200 can be fixedly installed or placed in the combustion chamber 111, or the combustion rack 200 can be pulled out of the combustion chamber 111 and put back into the combustion chamber 111. In one embodiment of the present invention, the combustion rack 200 is fixedly installed or placed in the combustion chamber 111, and fuel can be placed on the combustion rack 200 through the inlet end and / or the outlet end. The fuel can be ignited by extending an igniter into the combustion rack 200 for ignition or by installing the igniter on the combustion rack 200, and igniting the igniter through a circuit or mechanical connection, thereby causing the fuel to start burning.

[0046] In other embodiments of the present invention, the combustion rack 200 can be withdrawn from the combustion chamber 111 and put back into the combustion chamber 111. Figure 1-4As shown, as an achievable method, the solid tracer particle generator 10 further includes a push-pull frame 300, a push-pull port is further provided on the connecting flow channel 100, the push-pull port is communicated with the combustion chamber 111, the push-pull frame 300 is detachably arranged at the push-pull port, and the push-pull frame 300 is fixedly connected to the combustion frame 200; when the push-pull frame 300 is installed at the push-pull port, the combustion frame 200 is pushed into the combustion chamber 111, and when the push-pull frame 300 is away from the push-pull port, the combustion frame 200 is pulled out of the combustion chamber 111. In this embodiment, the combustion frame 200 that can be pulled out of the combustion chamber 111 allows the operator to conveniently add fuel outside and ignite the fuel, and then push the combustion frame 200 back into the combustion chamber 111. Further, the push-pull frame 300 pushes the combustion frame 200 into the combustion chamber 111 in a horizontal direction, or the push-pull frame 300 pulls the combustion frame 200 out of the combustion chamber 111 in a horizontal direction. The movement direction of the combustion rack 200 is parallel to the horizontally arranged flow stabilizing grid 140 , so as to avoid interference between the combustion rack 200 and the flow stabilizing grid 140 when the combustion rack 200 moves.

[0047] Optionally, the push-pull frame 300 drives the combustion frame 200 to move in a horizontal or vertical direction. Figure 1-3 As shown, in a specific embodiment of the present invention, the push-pull frame 300 drives the combustion frame 200 to move horizontally. A push-pull flange 150 is formed at the push-pull opening, and the push-pull frame 300 includes a push-pull panel 310, and the push-pull panel 310 is detachably fixedly connected to the push-pull flange 150 in a threaded connection. The connection between the push-pull panel 310 and the push-pull flange 150 ensures the sealing performance of the solid tracer particle generator 10 while realizing the mobility of the combustion frame 200. As a feasible method, a push-pull handle 320 is installed on the side of the push-pull panel 310 away from the combustion frame 200 for easy pushing and pulling.

[0048] In one embodiment of the present invention, Figure 1-4As shown, the combustion rack 200 includes multiple layers of combustion trays 210, which are arranged in the combustion chamber 111 at intervals along the vertical direction, and the multiple layers of combustion trays 210 can carry fuel respectively. The connecting flow channel 100 also includes a positioning plate 160, which is arranged at the bottom of the combustion chamber 111. When the push-pull rack 300 drives the combustion rack 200 to enter or leave the combustion chamber 111, one layer of the combustion tray 210 slides and fits with the upper surface of the positioning plate 160. One end of the multiple combustion trays 210 is respectively fixed to one side of the push-pull panel 310, and the positioning plate 160 can ensure the movement stability of the combustion rack 200 in the process of entering and leaving the combustion chamber 111. It can be realized that the positioning plate 160 is fixedly connected to the inner wall of the combustion chamber 111 or supported by a specific bracket to ensure that the positioning plate 160 can support at least one combustion tray 210 at a specific height. Furthermore, when the push-pull frame 300 drives the combustion frame 200 to enter or leave the combustion chamber 111, the bottom combustion tray 210 slides and fits with the upper surface of the positioning plate 160. In the above embodiment, the combustion frame 200 is pulled out of the combustion chamber 111 and then a suitable fuel is put in. After the fuel is ignited, the combustion frame 200 is pushed into the combustion chamber 111, or the combustion frame 200 is first pushed into the combustion chamber 111 and then the igniter installed on the combustion frame 200 is used to ignite the fuel.

[0049] In the above embodiment, the built-in solid tracer particle generator 10 is conducive to the precise control of the experimental fluid flow rate while ensuring the uniformity of the tracer particles. The multi-layer parallel combustion tray 210 ensures the uniformity of the distribution of solid tracer particles in the experimental flow channel and the controllability of the concentration. The downstream only needs a short development distance to achieve the effect of uniform distribution of solid tracer particles in the flow field. The pull-out combustion rack 200 is conducive to taking and placing fuel and adjusting the fuel amount. The number of layers of the combustion tray 210 can be adapted according to the size of the experimental flow channel and the concentration requirements of the tracer particles. And the flow stabilizing grid 140 combined with the semi-enclosed combustion tray 210 ensures the stability and good followability of the generation of solid tracer particles. The flow stabilizing grid 140 can greatly reduce the local flow velocity by generating low-speed vortices, so that the solid fuel can still burn stably inside the experimental flow channel, and the generated solid tracer particles can be entrained from the combustion tray 210 into the mainstream of the experimental fluid by suction and enter the downstream flow field. The flue gas particles produced by solid fuel combustion are very small, which ensures the tracking ability of the tracer particles, especially under low-speed experimental conditions.

[0050] Figure 6It is a numerical simulation cloud map of the concentration distribution of solid tracer particles in the flow field in one embodiment of the present invention. The numerical simulation is calculated by the software ANSYS CFX, and a point source is given inside each combustion tray 210 to simulate the solid tracer particle generation process. The distribution effect of the solid tracer particles in the downstream depends to a great extent on the injection method of the solid tracer particles in the experimental flow channel. Compared with the traditional external pump-in generation method, the embedded particle generation method ensures the uniformity and good followability of the downstream solid tracer particle distribution, and only requires a very short flow distance to achieve a uniform distribution effect. The pull-out parallel combustion tray 210 structure is conducive to taking and placing fuel and adjusting the fuel amount. The number of parallel layers of the combustion tray 210 can be adapted according to the size of the experimental flow channel and the concentration requirements of the tracer particles.

[0051] Figure 7 It is a numerical simulation cloud diagram of the fluid velocity distribution in the flow channel of the present invention. The difficulty of the embedded particle generation method is how to ensure the stability and good followability of the solid tracer particles. The flow stabilization grid 140 can greatly reduce the local flow velocity by generating low-speed vortices, so that the solid fuel can still burn stably inside the flow channel. At the same time, the generated tracer particles are entrained into the mainstream of the experimental fluid at a lower flow rate by air entrainment, providing stable solid tracer particles with good followability for the flow measurement experiment.

[0052] An embodiment of the present invention also provides a flow field measurement device for measuring the flow field distribution of a fluid (generally a gas) (the flow velocity of the fluid and the distribution of the fluid in a spatial range). The flow field measurement device includes an experimental flow channel and a solid tracer particle generator 10 described in any one of the above embodiments, and the solid tracer particle generator 10 is connected in series to the flow channel. In the above flow field measurement device, the solid tracer particle generator 10 is embedded in the experimental flow channel, and the entire process of solid tracer particle generation is completed in the experimental flow channel. During the experiment, the fuel can burn with the air in the experimental flow channel to generate solid tracer particles without the need for additional gas flow. The solid tracer particles are generated in the experimental flow channel without the need for additional pumping steps, which effectively avoids the influence of the pumped gas with a relatively high pressure on the fluid flow in the experimental flow channel, and facilitates the control of the experimental fluid flow. In addition, the solid tracer particles are generated in the experimental flow channel, and the generated solid tracer particles directly enter the experimental fluid and are only driven by the experimental fluid, which ensures the followability of the solid tracer particles to the fluid. The above solid tracer particle generator 10 and the flow field measurement device have high measurement accuracy for the flow field.

[0053] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0054] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A solid tracer particle generator, characterized in that: The solid tracer particle generator comprises: A connecting flow channel is formed with a hollow combustion cavity inside, and the combustion cavity can be connected in series to the experimental flow channel, thereby allowing the experimental fluid in the experimental flow channel to flow through the combustion cavity; A combustion rack is arranged in the combustion chamber, and the combustion rack can carry fuel. The tracer particles generated after the fuel is ignited can mix with the experimental fluid in the experimental flow channel and move with the experimental fluid; the combustion rack includes a plurality of combustion trays, and the plurality of combustion trays are arranged in the combustion chamber at intervals along the vertical direction, and the plurality of combustion trays can carry fuel respectively; the plurality of combustion trays are arranged in parallel, and the direction in which the plurality of combustion trays are arranged at intervals is perpendicular to the flow direction of the experimental fluid in the combustion chamber; the combustion tray includes a bottom plate and a retaining edge formed by bending the bottom plate upward along the outer periphery.

2. The solid tracer particle generator according to claim 1, characterized in that: The connecting flow channel includes a flow stabilizing portion, which is disposed in the combustion chamber and is used to slow down the flow rate of the experimental fluid flowing through the combustion tray.

3. The solid tracer particle generator according to claim 2, characterized in that: The flow stabilizing portion comprises a plurality of layers of flow stabilizing grids, which are arranged in the combustion chamber at intervals along a vertical direction, and each layer of the flow stabilizing grids is respectively located at an opening of a layer of the combustion tray.

4. The solid tracer particle generator according to claim 1, characterized in that: The connecting flow channel includes a combustion section, an inlet end and an outlet end. A hollow combustion chamber is formed inside the combustion section. The inlet end is arranged upstream of the combustion section along the flow direction of the experimental fluid, and the outlet end is arranged downstream of the combustion section along the flow direction of the experimental fluid. The inlet end and the outlet end are respectively detachably fixedly connected to the experimental flow channel.

5. The solid tracer particle generator according to claim 4, characterized in that: The inlet end includes an inlet flange, and the outlet end includes an outlet flange. The inlet flange and the outlet flange can be detachably fixedly connected to the experimental flow channel respectively, so that the combustion chamber can be connected in series to the experimental flow channel.

6. The solid tracer particle generator according to claim 4, characterized in that: The connection direction of the inlet end, the combustion section and the outlet end on the connecting flow channel is a straight line, a curve or a broken line.

7. The solid tracer particle generator according to any one of claims 1 to 6, characterized in that: The solid tracer particle generator further comprises an igniter, which is disposed on the combustion rack and is used to ignite the fuel on the combustion rack.

8. The solid tracer particle generator according to any one of claims 1 to 6, characterized in that: The solid tracer particle generator also includes a push-pull frame, and a push-pull port is also provided on the connecting flow channel, the push-pull port is connected to the combustion chamber, the push-pull frame is detachably arranged at the push-pull port, and the push-pull frame is fixedly connected to the combustion frame; when the push-pull frame is installed at the push-pull port, the combustion frame is pushed into the combustion chamber, and when the push-pull frame is away from the push-pull port, the combustion frame is pulled out of the combustion chamber.

9. The solid tracer particle generator according to claim 8, characterized in that: The push-pull frame pushes the combustion frame into the combustion chamber along a horizontal direction, or the push-pull frame pulls the combustion frame out of the combustion chamber along a horizontal direction.

10. The solid tracer particle generator according to claim 8, characterized in that: A push-pull flange is formed at the push-pull opening, and the push-pull frame includes a push-pull panel. The push-pull panel is detachably fixedly connected to the push-pull flange in a threaded connection manner.

11. The solid tracer particle generator according to claim 8, characterized in that: The combustion rack includes multiple layers of combustion trays, which are arranged in the combustion chamber at intervals along the vertical direction, and the multiple layers of combustion trays can carry fuel respectively; the connecting flow channel also includes a positioning plate, which is arranged at the bottom of the combustion chamber, and when the push-pull rack drives the combustion rack to enter or leave the combustion chamber, one layer of the combustion tray slides and fits with the upper surface of the positioning plate.

12. The solid tracer particle generator according to claim 11, characterized in that: When the push-pull frame drives the combustion frame to enter or leave the combustion chamber, the combustion tray at the bottom layer slides and fits with the upper surface of the positioning plate.

13. A flow field measuring device for measuring the flow field distribution of a fluid, characterized in that: The flow field measurement device comprises an experimental flow channel and the solid tracer particle generator according to any one of claims 1 to 12, and the solid tracer particle generator is connected in series to the flow channel.

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