阅读说明：本技术 固体示踪颗粒发生器及流场测量装置 (Solid tracer particle generator and flow field measuring device ) 是由 任静 李雪英 赵珂 于 2020-04-30 设计创作，主要内容包括：本发明涉及一种固体示踪颗粒发生器,固体示踪颗粒发生器包括连接流道和燃烧架。连接流道内部形成中空的燃烧腔体,燃烧腔体能够串接于实验流道,进而允许实验流道内的实验流体流经燃烧腔体。燃烧架设置于燃烧腔体内,燃烧架能够承载燃料,点燃燃料后产生的示踪颗粒能够与实验流道内的实验流体混合并随实验流体运动。本发明还涉及一种包括上述固体示踪颗粒发生器的流场测量装置。上述固体示踪颗粒发生器及流场测量装置,固体示踪颗粒发生的整个过程全部在实验流道内完成,在实验进行过程中燃料能够与实验流道内的空气燃烧产生固体示踪颗粒,无需额外气体流量加入,便于实验流体流量的控制,且保证了固体示踪颗粒对流体的跟随性。(The invention relates to a solid tracer particle generator which comprises a connecting flow channel and a combustion frame. The connecting flow channel is internally provided with a hollow combustion cavity, and the combustion cavity can be connected in series with the experiment flow channel, so that the experiment fluid in the experiment flow channel can flow through the combustion cavity. The burning frame sets up in the combustion chamber, and the burning frame can bear fuel, ignites the tracer particle that produces after the fuel and can mix and along with the experiment fluid motion in the experiment runner. The invention also relates to a flow field measuring device comprising the solid tracer particle generator. Above-mentioned solid tracer particle generator and flow field measuring device, whole process that solid tracer particle takes place is whole to be accomplished in the experiment runner, carries out the in-process fuel in the experiment and can produce solid tracer particle with the air combustion in the experiment runner, need not extra gas flow and adds, and the control of the experimental fluid flow of being convenient for has just guaranteed the followability of solid tracer particle to the fluid.)

1. A solid trace particle generator, comprising:

the test device comprises a connecting flow channel, a test flow channel and a control device, wherein a hollow combustion cavity is formed inside the connecting flow channel, and the combustion cavity can be connected in series with the test flow channel so as to allow test fluid in the test flow channel to flow through the combustion cavity;

the burning frame set up in the burning cavity, burning frame can bear fuel, and the tracer particle that produces after lighting fuel can mix and along with the experiment fluid motion in the experiment runner.

2. The solid tracer particle generator of claim 1, wherein the combustion rack includes a plurality of layers of combustion trays spaced apart vertically within the combustion chamber, the plurality of layers of combustion trays being capable of carrying fuel, respectively.

3. The solid tracer particle generator of claim 2, wherein the plurality of combustion trays are arranged in parallel, and the plurality of combustion trays are spaced apart in a direction perpendicular to the flow direction of the test fluid in the combustion chamber.

4. The solid tracer particle generator of claim 3, wherein the connection flow channel includes a flow stabilizer disposed within the combustion chamber for slowing a flow rate of the test fluid flowing through the combustion tray.

5. The solid tracer particle generator of claim 4, wherein the flow stabilizer includes a plurality of layers of flow stabilizing grids spaced vertically within the combustion chamber, each layer of flow stabilizing grids being positioned at an opening of one of the layers of the combustion tray.

6. The solid tracer particle generator of claim 1, wherein the connection flow channel comprises 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 test fluid, the outlet end is arranged downstream of the combustion section along the flow direction of the test fluid, and the inlet end and the outlet end are respectively and fixedly connected with the test flow channel in a detachable manner.

7. The solid tracer particle generator of claim 6, wherein the inlet end comprises an inlet flange, the outlet end comprises an outlet flange, the inlet flange and the outlet flange are respectively detachably and fixedly connected with the experimental flow channel, and the combustion chamber is connected in series with the experimental flow channel.

8. The solid tracer particle generator of claim 6, wherein a line connecting the inlet end, the combustion section, and the outlet end of the connecting flow path is straight, curved, or broken.

9. The solid trace particle generator of any of claims 1-8, further comprising an igniter disposed on the combustion rack, the igniter configured to ignite fuel on the combustion rack.

10. The solid tracer particle generator of any of claims 1-8, further comprising a push-pull frame, wherein the connection flow channel is further provided with a push-pull opening, the push-pull opening is communicated with the combustion chamber, the push-pull frame is detachably disposed on the push-pull opening, and the push-pull frame is fixedly connected with the combustion frame; the combustion rack is pushed to the inside of the combustion cavity when the push-pull frame is arranged on the push-pull opening, and the combustion rack is pulled to the outside of the combustion cavity when the push-pull frame is far away from the push-pull opening.

11. The solid trace particle generator of claim 10, wherein the push-pull carriage pushes the combustion carriage horizontally into the combustion chamber or the push-pull carriage pulls the combustion carriage horizontally out of the combustion chamber.

12. The solid tracer particle generator of claim 10, wherein the push-pull port forms a push-pull flange, and the push-pull frame comprises a push-pull panel that is removably and fixedly connected to the push-pull flange in a threaded connection.

13. The solid tracer particle generator of claim 10, wherein the combustion rack includes a plurality of layers of combustion trays spaced apart vertically within the combustion chamber, the plurality of layers of combustion trays being capable of carrying fuel, respectively; the connecting flow channel further comprises a positioning disc, the positioning disc is arranged at the bottom of the combustion cavity, the push-pull frame drives the combustion frame to enter or leave the combustion cavity, and the upper surface of one layer of the combustion tray is in sliding fit with the upper surface of the positioning disc.

14. The solid tracer particle generator of claim 13, wherein the combustion tray at the bottom layer is in sliding engagement with the upper surface of the positioning plate during movement of the combustion frame into and out of the combustion chamber by the push-pull carriage.

15. A flow field measurement device for measuring the flow field distribution of a fluid, comprising an experimental flow channel and a solid tracer particle generator according to any of claims 1 to 14, the solid tracer particle generator being connected in series to the flow channel.

Technical Field

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

Background

Particle Image Velocimetry (PIV) is a non-contact laser optical measurement technology, can be used for research and measurement of fluid motion processes such as flow, turbulence, spray atomization and combustion, and can perform relatively accurate flow velocity measurement under the condition of not contacting a flow field. The precondition of accurately measuring the flow field by a particle image velocimetry method is the generation of tracer particles. A typical tracer particle generator generates tracer particles outside the flow channel and then uses pumping to add the tracer particles to the flow channel. A relatively large gas pressure is generally required in the process of pumping the tracer particles into the flow channel, which can 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 difficult to be matched with the flow speed of the original fluid, and the following performance of the tracer particles to the fluid is poor. Disturbing the fluid flow in the flow channel and poor tracking of the fluid by the tracer particles results in a less accurate measurement of the flow field.

Disclosure of Invention

Based on this, it is necessary to provide a solid trace particle generator and a flow field measuring device with higher flow field measurement accuracy, aiming at the problem that the existing trace particle generator has lower flow field measurement accuracy due to the pumping of trace particles.

A solid trace particle generator, comprising:

the test device comprises a connecting flow channel, a test flow channel and a control device, wherein a hollow combustion cavity is formed inside the connecting flow channel, and the combustion cavity can be connected in series with the test flow channel so as to allow test fluid in the test flow channel to flow through the combustion cavity;

the burning frame set up in the burning cavity, burning frame can bear fuel, and the tracer particle that produces after lighting fuel can mix and along with the experiment fluid motion in the experiment runner.

In one embodiment, the combustion rack comprises a plurality of layers of combustion trays, the plurality of layers of combustion trays are arranged in the combustion cavity at intervals along the vertical direction, and the plurality of layers of combustion trays can respectively bear fuel.

In one embodiment, the plurality of layers of the combustion trays are arranged in parallel, and the direction of the plurality of layers of the combustion trays arranged at intervals is perpendicular to the flowing direction of the experimental fluid in the combustion cavity.

In one embodiment, the connection flow passage includes a flow stabilizing portion disposed in the combustion chamber, and the flow stabilizing portion is configured to slow a flow rate of the test fluid flowing through the combustion tray.

In one embodiment, the flow stabilizing part comprises a plurality of layers of flow stabilizing grids, the plurality of layers of flow stabilizing grids are arranged in the combustion cavity at intervals along the vertical direction, and each layer of flow stabilizing grid is respectively positioned at an opening of one layer of the combustion tray.

In one embodiment, the connection flow channel comprises a combustion section, an inlet end and an outlet end, a hollow combustion cavity is formed in the combustion section, the inlet end is arranged on the upstream of the combustion section along the flow direction of the experimental fluid, the outlet end is arranged on the downstream of the combustion section along the flow direction of the experimental fluid, and the inlet end and the outlet end are respectively and fixedly connected with the experimental flow channel in a detachable mode.

In one embodiment, the inlet end comprises an inlet flange, the outlet end comprises an outlet flange, the inlet flange and the outlet flange can be respectively and fixedly connected with the experiment flow channel in a detachable mode, and then the combustion chamber can be connected in series with the experiment flow channel.

In one embodiment, a connection line between the inlet end, the combustion section and the outlet end of the connection flow channel is a straight line, a curved line or a broken line.

In one embodiment, the solid trace particle generator further comprises an igniter disposed on the combustion rack, the igniter being configured to ignite the fuel on the combustion rack.

In one embodiment, the solid trace particle generator further comprises a push-pull frame, a push-pull opening is further formed in the connecting flow channel, the push-pull opening is communicated with the combustion cavity, the push-pull frame is detachably arranged on the push-pull opening, and the push-pull frame is fixedly connected with the combustion frame; the combustion rack is pushed to the inside of the combustion cavity when the push-pull frame is arranged on the push-pull opening, and the combustion rack is pulled to the outside of the combustion cavity when the push-pull frame is far away from the push-pull opening.

In one embodiment, the push-pull frame pushes the combustion frame into the combustion cavity along a horizontal direction, or the push-pull frame pulls the combustion frame out of the combustion cavity along the horizontal direction.

In one embodiment, the push-pull opening is formed with a push-pull flange, and the push-pull frame comprises a push-pull panel which is detachably and fixedly connected with the push-pull flange in a threaded manner.

In one embodiment, the combustion rack comprises a plurality of layers of combustion trays, the plurality of layers of combustion trays are arranged in the combustion cavity at intervals along the vertical direction, and the plurality of layers of combustion trays can respectively bear fuel; the connecting flow channel further comprises a positioning disc, the positioning disc is arranged at the bottom of the combustion cavity, the push-pull frame drives the combustion frame to enter or leave the combustion cavity, and the upper surface of one layer of the combustion tray is in sliding fit with the upper surface of the positioning disc.

In one embodiment, in the process that the push-pull frame drives the combustion frame to enter or leave the combustion cavity, the combustion tray at the bottommost layer is in sliding fit with the upper surface of the positioning disc.

A flow field measuring device is used for measuring the flow field distribution of fluid and comprises an experimental flow channel and a solid tracer particle generator in any one of the schemes, wherein the solid tracer particle generator is connected in series with the flow channel.

Above-mentioned solid tracer particle generator and flow field measuring device, solid tracer particle generator are embedded in the experiment runner, and the whole process that solid tracer particle takes place is all accomplished in the experiment runner, carries out the in-process fuel in the experiment and can produce the solid tracer particle with the air combustion in the experiment runner, need not extra gas flow and adds. The solid tracer particles are generated in the experiment flow channel, extra pumping steps are not needed, the influence of pumping gas with larger pressure on the fluid flow in the experiment flow channel is effectively avoided, and the control of the experiment fluid flow is convenient. And 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, so that the following performance of the solid tracer particles to the fluid is ensured. The solid tracer particle generator and the flow field measuring device have high measurement precision on the flow field.

Drawings

Fig. 1 is a schematic structural diagram of a solid trace particle generator according to an embodiment of the present invention;

FIG. 2 is a schematic view of a connecting flow channel structure according to an embodiment of the present invention;

FIG. 3 is a schematic view of the assembly of a combustion frame and a push-pull frame according to an embodiment of the present invention;

FIG. 4 is a schematic view of the assembly of a burner block, a push-pull block, a flow-stabilizing grate, and a positioning plate according to an embodiment of the present invention;

FIG. 5 is a schematic view of a flow stabilizing grid according to an embodiment of the present invention;

FIG. 6 is a schematic illustration of the concentration of solid tracer particles in an experimental flow path according to an embodiment of the present invention;

fig. 7 is a schematic diagram of the velocity of the solid tracer particles in the experimental flow channel according to an embodiment of the present invention.

Wherein: 10. a solid trace particle generator; 100. connecting the flow channel; 110. a combustion section; 111. a combustion chamber; 120. an inlet flange; 130. an outlet flange; 140. a flow stabilizing grid; 150. pushing a venlafaxine; 160. positioning a plate; 200. a combustion rack; 210. a combustion tray; 300. a push-pull frame; 310. a push-pull panel; 320. push-pull handle.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The invention relates to a tracing particle generator, in particular to a flow channel embedded type solid tracing particle generator suitable for PIV flow display measurement, which provides stable and well-followed solid tracing particles for fluid mechanics experimental research related to aerospace, energy power and building environment. The generation method of the embedded tracer particles of the experimental flow channel is one of effective ways for solving the problems of accurate control of experimental gas flow, uniformity of tracer particles and poor following performance.

As shown in fig. 1-3, an embodiment of the present invention provides a solid trace particle generator 10 including a connecting flow channel 100 and a combustion frame 200. The connection flow channel 100 is used for communicating with the experiment flow channel, and the connection flow channel 100 is connected in series with the experiment flow channel. The combustion rack 200 is installed in the experimental runner for supporting the fuel to be combusted. Specifically, a hollow combustion chamber 111 is formed inside the connection flow channel 100, and the combustion chamber 111 can be connected in series to the experiment flow channel, so as to allow the experiment fluid in the experiment flow channel to flow through the combustion chamber 111. The combustion frame 200 is arranged in the combustion cavity 111, the combustion frame 200 can bear fuel, and tracer particles generated after the fuel is ignited can be mixed with experimental fluid in an experimental flow channel and move along with the experimental fluid. It is understood that the connection between the connection flow channel 100 and the experimental flow channel is a detachable fixed connection (such as a threaded connection, a clamping connection, etc.) or a non-detachable fixed connection (such as a welding connection, etc.); even the connection channel 100 and the experimental channel may be integrated, in which case a certain section of the experimental channel serves as the connection channel 100. Accordingly, the present embodiment provides a solid trace particle generator 10 that may be disposable or reusable. The specific connection relationship between the solid trace particle generator 10 and the experimental flow channel is not limited in this embodiment.

Above-mentioned solid tracer particle generator 10, solid tracer particle generator 10 is embedded in the experiment runner, and the whole process that solid tracer particle takes place is all accomplished in the experiment runner, carries out the in-process fuel in the experiment and can produce the solid tracer particle with the air combustion in the experiment runner, need not extra gas flow and adds. The solid tracer particles are generated in the experiment flow channel, extra pumping steps are not needed, the influence of pumping gas with larger pressure on the fluid flow in the experiment flow channel is effectively avoided, and the control of the experiment fluid flow is convenient. And 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, so that the following performance of the solid tracer particles to the fluid is ensured. The solid tracer particle generator 10 and the flow field measuring device have high accuracy in measuring the flow field.

The uniform mixing and synchronous following of the solid tracer particles with the test fluid is a key step in flow field measurement. As shown in fig. 1 to 4, in an embodiment of the present invention, the combustion rack 200 includes a plurality of combustion trays 210, the plurality of combustion trays 210 are vertically spaced apart from each other in the combustion chamber 111, and the plurality of combustion trays 210 can respectively carry fuel. Bear the weight of the fuel that can produce solid tracer particle respectively on the multilayer burning tray 210, just along vertical direction interval distribution when solid tracer particle produces with the mode of burning, be favorable to solid tracer particle to carry out intensive mixing with the experiment fluid in whole experiment runner. Further, the plurality of layers of combustion trays 210 are arranged in parallel, and the direction of the plurality of layers of combustion trays 210 arranged at intervals is perpendicular to the flowing direction of the experimental fluid in the combustion chamber 111. The parallel arrangement of the trays allows for a more uniform distribution of the solid tracer particles produced by the fuel in the space. And the direction that the multilayer burning tray 210 set up at interval is perpendicular with the flow direction of experimental fluid in combustion chamber 111, and then burning tray 210 is parallel to the bearing surface of fuel and the flow direction of experimental fluid, can reduce the resistance that burning tray 210 caused the flow of experimental fluid to the at utmost. The number of layers of the combustion tray 210 may be adapted according to the experimental flow channel size and the concentration requirements for the solid tracer particles.

Alternatively, the plurality of combustion trays 210 are respectively fixed to the inner wall of the combustion chamber 111 or supported by a tray support. The multi-layer combustion trays 210 can also be designed to be distributed at equal intervals or distributed at unequal intervals according to the actual working conditions of the experimental fluid. As shown in fig. 1 to 4, the burner block 200 includes five-layer burner trays 210 in a manner that the five-layer burner trays 210 are spaced apart from each other at equal intervals in a vertical direction, and the five-layer burner trays 210 are supported by a tray support. Specifically, the combustion tray 210 includes a bottom plate and a rib formed by bending the bottom plate upward along an outer periphery, and such a combustion tray 210 is semi-enclosed. The amount of fuel placed on each combustion tray 210 during a single flow field measurement may be set according to measurement requirements. For further explanation, the vertical direction in which the plurality of combustion trays 210 are arranged at intervals is defined as the Z direction in the drawing, the flow direction of the test fluid is defined as the horizontal longitudinal direction (X direction in the drawing), and the direction perpendicular to the vertical direction and the horizontal longitudinal direction is defined as the horizontal lateral direction (Y direction in the drawing).

The experimental fluid in the experimental flow channel and the connecting flow channel 100 flows through the combustion tray 210 at a set range of flow rate, the fuel in the combustion tray 210 contacts with the gas in the experimental fluid to be combusted, and the stable combustion of the fuel is the key for generating solid tracer particles with uniform size and uniform concentration. In an embodiment of the present invention, the connection flow channel 100 includes a flow stabilizer disposed in the combustion chamber 111, and the flow stabilizer is configured to slow down a flow rate of the experimental fluid flowing through the combustion tray 210, so as to provide a suitable airflow for uniform and stable combustion of the fuel. As one way of achieving this, as shown in fig. 2 to 5, the flow stabilizer includes a multi-layered flow stabilization grid 140, the multi-layered flow stabilization grid 140 is disposed in the combustion chamber 111 at intervals in the vertical direction, and each layer of flow stabilization grid 140 is located at an opening of one layer of the combustion tray 210. In other embodiments, the flow stabilizer may be a layer of high temperature resistant mesh covering the opening of the combustion tray 210.

The steady flow grating 140 is provided with a plurality of air holes, when flowing through the steady flow grating 140, the experimental fluid flowing along the horizontal longitudinal direction (X direction) can move downwards along the vertical direction (Z direction) through the air holes and then contact with the fuel, and because the flowing direction of the experimental fluid is mainly the horizontal longitudinal direction (X direction), the flow speed ratio of the experimental fluid passing through the air holes along the vertical direction (Z direction) is low, so that the fuel can be allowed to be uniformly, stably and fully combusted, and uniform tracer particles are generated. And the solid tracer particles generated by combustion can enter the main flow of the experimental fluid from the air holes of the steady flow grid 140 in a main flow entrainment mode, and then the solid tracer particles are dispersed in the whole experimental flow channel under the driving of the experimental fluid, so that the stable following of the solid tracer particles to the experimental fluid is realized. Optionally, similar to the fixing manner of the combustion tray 210, the multilayer flow stabilization grids 140 are respectively fixed on the inner wall of the combustion cavity 111 or supported by grid supports, so that the multilayer flow stabilization grids 140 are distributed at intervals in the vertical direction and are in one-to-one correspondence with the multilayer combustion tray 210. In other embodiments of the present invention, the flow stabilizing grid 140 and the combustion tray 210 may be fixed together to form a single body.

In one embodiment of the present invention, the solid trace particle generator 10 is detachably and fixedly connected to and in communication with the experimental flow path. As shown in fig. 1 to 3, specifically, the connection 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 disposed on the upstream of the combustion section 110 along the flow direction of the test fluid, the outlet end is disposed on the downstream of the combustion section 110 along the flow direction of the test fluid, and the inlet end and the outlet end are respectively and fixedly connected to the test flow channel in a detachable manner. Optionally, the inlet end and the outlet end of the solid trace particle generator 10 are respectively connected with the experimental flow channel in the same or different manners, and are provided with necessary sealing measures, such as threaded connection, clamping connection and the like. As an achievable way, the inlet end includes an inlet flange 120, the outlet end includes an outlet flange 130, the inlet flange 120 and the outlet flange 130 can be detachably and fixedly connected with the experimental flow channel through bolts or screws, respectively, and then the combustion chamber 111 can be connected in series with the experimental flow channel. It is understood that the portions of the experimental flow channel connected to the inlet flange 120 and the outlet flange 130 are also provided with corresponding connecting flanges. The flange connection mode is used, the communication between the solid tracing particle generator 10 and an experimental flow channel can be guaranteed, the whole flow field measuring device can be conveniently installed and maintained, and the solid tracing particle generator 10 can be disassembled and assembled by using bolts when necessary.

As shown in fig. 1 to 3, in the above embodiments, the connecting line direction of the inlet end, the combustion section 110 and the outlet end on the connecting flow channel 100 is a straight line, which can reduce the flow resistance of the connecting flow channel 100 to the test fluid to the maximum extent, and ensure that the solid tracer particles generated by combustion can be quickly taken away by the test fluid. In other embodiments, the connecting line connecting the inlet end, the combustion section 110 and the outlet end of the flow channel 100 is curved or broken, so long as the solid trace particle generator 10 is adaptive to the actual conditions.

In the above embodiments, the combustion frame 200 may be fixedly installed or placed in the combustion chamber 111, or the combustion frame 200 may be drawn 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 put into the combustion rack 200 through the inlet end and/or the outlet end. The fuel may be ignited by inserting an igniter into the combustion rack 200 to ignite the fuel or by installing an igniter on the combustion rack 200 and operating the igniter through an electrical circuit or mechanical connection to ignite the fuel, thereby initiating combustion of the fuel.

In other embodiments of the present invention, the combustion rack 200 may be withdrawn from the combustion chamber 111 and replaced in the combustion chamber 111. As shown in fig. 1 to 4, as an implementation manner, the solid trace particle generator 10 further includes a push-pull frame 300, the connection flow channel 100 is further provided with a push-pull opening, the push-pull opening is communicated with the combustion chamber 111, the push-pull frame 300 is detachably disposed at the push-pull opening, and the push-pull frame 300 is fixedly connected with the combustion frame 200; the push-pull frame 300 is installed in the push-pull opening to push the combustion frame 200 into the combustion chamber 111, and the push-pull frame 300 is away from the push-pull opening to pull the combustion frame 200 out of the combustion chamber 111. In this embodiment, the combustion rack 200 capable of being pulled out of the combustion chamber 111 allows an operator to easily add fuel to the outside and ignite the fuel, and then push the combustion rack 200 back into the combustion chamber 111. Further, the push-pull frame 300 pushes the combustion frame 200 into the combustion chamber 111 along the horizontal direction, or the push-pull frame 300 pulls the combustion frame 200 out of the combustion chamber 111 along the horizontal direction. The moving direction of the combustion rack 200 is parallel to the horizontally arranged flow stabilization grating 140, so that interference between the combustion rack 200 and the flow stabilization grating 140 during movement is avoided.

Optionally, the direction of the movement of the combustion frame 200 driven by the push-pull frame 300 is horizontal transverse direction or horizontal longitudinal direction. As shown in fig. 1-3, in one embodiment of the present invention, the push-pull frame 300 moves the combustion rack 200 in a horizontal lateral direction. The push-pull opening is provided with a push-pull flange 150, the push-pull frame 300 comprises a push-pull panel 310, and the push-pull panel 310 and the push-pull flange 150 are detachably and fixedly connected in a threaded manner. The connection between the push-pull panels 310 and the push-pull flanges 150 allows the combustion frame 200 to be movable while ensuring the sealing performance of the solid trace particle generator 10. As a practical matter, the side of the push-pull panel 310 away from the combustion rack 200 is provided with a push-pull handle 320 for easy pushing and pulling.

In an embodiment of the present invention, as shown in fig. 1 to 4, the combustion rack 200 includes a plurality of layers of combustion trays 210, the plurality of layers of combustion trays 210 are disposed in the combustion chamber 111 at intervals along a vertical direction, and the plurality of layers of combustion trays 210 can respectively carry fuel. The connecting flow channel 100 further comprises a positioning disc 160, the positioning disc 160 is disposed at the bottom of the combustion chamber 111, and the push-pull frame 300 drives the combustion frame 200 to enter or exit the combustion chamber 111, wherein the upper surface of the positioning disc 160 is in sliding fit with the combustion tray 210. One end of each of the plurality of combustion trays 210 is fixed to one side of the push-pull panel 310, and the positioning plate 160 can ensure the motion stability of the combustion rack 200 in the process of entering and exiting the combustion chamber 111. It can be realized that the positioning plate 160 is fixedly connected with the inner wall of the combustion chamber 111 or supported by a specific bracket, so that the positioning plate 160 can support at least one combustion tray 210 at a specific height. Further, in the process that the push-pull frame 300 drives the combustion frame 200 to enter or leave the combustion chamber 111, the combustion tray 210 at the bottommost layer is in sliding fit 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, then a proper amount of fuel is put in, and the combustion frame 200 is pushed into the combustion chamber 111 after the fuel is ignited, or the combustion frame 200 is pushed into the combustion chamber 111 first, and then the fuel is ignited by using an igniter mounted on the combustion frame 200.

In the above embodiment, the built-in solid tracer particle generator 10 facilitates accurate control of the experimental fluid flow while ensuring tracer particle uniformity. The multilayer parallel arrangement of the combustion tray 210 ensures the uniformity of the distribution of the solid tracer particles in the experimental flow channel and the controllability of the concentration. The effect of uniform distribution of the solid tracer particles in the flow field can be achieved only by a short development distance in the downstream. The combustion frame 200 that can pull out is in favor of getting and putting fuel and adjusting the fuel quantity, can adapt the number of layers of burning tray 210 according to experiment runner size and the concentration demand to the tracer particle. And the flow stabilization grid 140 in combination with the semi-enclosed combustion tray 210 ensures stability and good tracking of the solid tracer particle production. The flow stabilizing grid 140 can greatly reduce the local flow velocity by generating a low-speed vortex, so that the solid fuel can still be stably combusted in the experiment flow channel, and the generated solid tracer particles can be entrained into the main flow of the experiment fluid from the combustion tray 210 in an entrainment mode and enter a downstream flow field. The particle size of flue gas particles generated by burning the solid fuel is very small, the following performance of the tracer particles is ensured, and particularly, the tracer particles are used under the low-speed experimental working condition.

Fig. 6 is a numerically simulated cloud of the concentration distribution of solid tracer particles in a flow field in accordance with an embodiment of the invention. The numerical simulation is given by the software ANSYS CFX calculation, where a given point source inside each combustion tray 210 simulates the solid tracer particle generation process. The downstream distribution of the solid tracer particles is largely dependent on the manner in which the solid tracer particles are injected into the experimental flow channel. Compared with the traditional external pumping type generation mode, the embedded particle generation mode ensures the uniformity and good following performance of the distribution of the downstream solid tracing particles, and can achieve the uniform distribution effect only by a very short flow distance. The structure of the drawing parallel type combustion tray 210 is beneficial to taking and placing fuel and adjusting the fuel quantity, and the parallel layer number of the combustion tray 210 can be adapted according to the size of an experimental runner and the concentration requirement of tracer particles.

Fig. 7 is a numerical simulation cloud chart of the velocity distribution of the fluid in the flow channel of the present invention, and the difficulty of the generation mode of the embedded particles lies in how to ensure the stability and good following performance of the generation of the solid tracer particles. The flow stabilization grid 140 can greatly reduce the local flow velocity by generating low-speed vortex, so that the solid fuel can still be stably combusted inside the flow channel. Meanwhile, the generated tracer particles are entrained into the main flow of the experimental fluid at a low flow speed in an air flow entrainment mode, so that stable and good-following-property solid tracer particles are provided for a flow measurement experiment.

An embodiment of the present invention further provides a flow field measuring device for measuring flow field distribution (flow velocity of a fluid and distribution of the fluid in a spatial range) of a fluid (generally a gas), the flow field measuring device includes an experimental flow channel and the solid trace particle generator 10 described in any one of the above embodiments, and the solid trace particle generator 10 is connected in series to the flow channel. Above-mentioned flow field measuring device, solid tracer particle generator 10 is embedded in the experiment runner, and the whole process that solid tracer particle takes place is all accomplished in the experiment runner, carries out the in-process fuel in the experiment and can produce solid tracer particle with the air combustion in the experiment runner, need not extra gas flow and adds. The solid tracer particles are generated in the experiment flow channel, extra pumping steps are not needed, the influence of pumping gas with larger pressure on the fluid flow in the experiment flow channel is effectively avoided, and the control of the experiment fluid flow is convenient. And 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, so that the following performance of the solid tracer particles to the fluid is ensured. The solid tracer particle generator 10 and the flow field measuring device have high accuracy in measuring the flow field.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.