CN113063958B

CN113063958B - Particle generator

Info

Publication number: CN113063958B
Application number: CN202110334403.XA
Authority: CN
Inventors: 夏溪; 杨溢凡; 张昊东; 白严; 任勇智
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2022-06-07
Anticipated expiration: 2041-03-29
Also published as: CN113063958A

Abstract

The invention discloses a particle generator, comprising: a first cavity; the second cavity is communicated with the first cavity through a jet flow channel; a diaphragm operable to vibrate and operable to drive the gas in the second chamber to vibrate; wherein, the wall of the cavity for limiting the first cavity is provided with an airflow inlet and an airflow outlet which are communicated with the first cavity. Produce the efflux through the vibrating diaphragm vibration, because of the efflux has great kinetic energy, consequently can spread fast to whole first cavity in the tracer particle that erupts through jet flow channel, the homogeneous mixing of tracer particle completion in first cavity promptly. If gas is introduced from the gas flow inlet, the gas uniformly mixed with the trace particles in the first cavity can be slowly blown out from the gas flow outlet and enters the flow field experiment section, so that the particle generator can be also suitable for low-flow-rate experiments.

Description

Particle generator

Technical Field

The embodiment of the invention relates to the technical field of particle tracing laser measurement, in particular to a particle generator.

Background

A particle image velocimetry is a transient, multipoint and non-contact fluid mechanics velocimetry developed in the end of seventies. The PIV technology is characterized by exceeding the limitation of single-point speed measurement technology, being capable of recording the speed distribution information of a large number of space points in the same transient state and providing abundant flow field space structures and flow characteristics. When a PIV experiment is carried out to measure the flow field velocity, generally, tracer particles are added into an air flow in advance, then, laser is emitted, and a camera confirms the motion state of the particles by capturing scattered light of the tracer particles, so that the flow state of the flow field is obtained.

The Particle Image Velocimetry (PIV) is a non-contact flow field optical diagnosis measurement technology, can realize the speed measurement of non-contact and instantaneous flow fields, and compared with invasive measurement means such as a hot wire anemometer, the PIV not only has the advantages of high precision and high resolution of a single-point test technology, but also can obtain transient images and overall structures displayed by a plane flow field. In the field of two-dimensional full-field speed measurement, PIV is a mature technology and is rapidly developed into a standard method for flow field measurement. In the PIV measurement of the velocity field, tracer particles are required to be scattered in the flow field, and the motion state of the tracer particles is determined by capturing the scattered light of the tracer particles, so that the flow state of the flow field is obtained.

The non-contact flow field measurement method has strict requirements on the tracer particles, and the tracer particles with larger particle sizes can not only destroy the original flow field structure, but also deteriorate the original image acquisition result and influence the experimental result. The common tracer particles in the air flow field are generally smaller than 10 μm, but in the actual use process, under the influence of factors such as environment and the like, a part of tracer particles are converged into larger particles, and if the particles are also scattered into an experimental section, the experimental result is greatly influenced. The conventional particle generator directly blows trace particles in a container into a flow field experiment section by using high-speed airflow, so that larger particles are also brought into the flow field to influence an experiment result.

And such particle image velocimetry needs to adopt high-speed airflow to blow the tracer particles in the container, so it is not suitable for low-flow rate experiments, when low-flow rate experiments are carried out, the blending effect of the tracer particles is very poor, and it is difficult to uniformly mix the tracer particles with the experimental gas.

Disclosure of Invention

The embodiment of the invention aims to provide a particle generator, which can reduce the probability of larger trace particles entering a flow field and can also be suitable for low-flow-rate experiments.

To solve the above technical problem, an embodiment of the present invention provides a particle generator including:

the first cavity is defined by a cavity wall, and an airflow inlet and an airflow outlet which are communicated with the first cavity are arranged on the cavity wall;

the second cavity is communicated with the first cavity through a jet flow channel;

an actuator in communication with the second chamber and operable to drive gas within the second chamber through the fluidic channel into the first chamber.

Compared with the prior art, the particle generator comprises a first cavity, a second cavity communicated with the first cavity through a jet flow channel, and an exciter capable of driving gas in the second cavity to enter the first cavity through the jet flow channel. In actual conditions, generally put into the second cavity with the tracer particle, the gaseous entering first cavity in the driver drive second cavity, and at this in-process, the tracer particle mixes with the gaseous entering first cavity in the second cavity, and the efflux is produced in first cavity in gaseous entering first cavity after the mixing through efflux passageway. Jet refers to a fluid flow in which a fluid is emitted from a nozzle, orifice, or slit (i.e., the above-described fluidic channel) and commingled with surrounding fluids, and the fluid is ejected from the nozzle or orifice, out of the confines of a solid boundary, and flows diffusively in a liquid or gas. Because the efflux has great kinetic energy, consequently the tracer particle who jets can spread fast in whole first cavity, and the tracer particle accomplishes the homogeneous mixing in first cavity promptly. If gas is introduced from the gas flow inlet, the gas uniformly mixed with the trace particles in the first cavity can be slowly blown out from the gas flow outlet and enters the flow field experiment section, so that the particle generator can be also suitable for low-flow-rate experiments.

Moreover, the gas mixed with the trace particles is blown into the first cavity in a driving gas movement mode, the trace particles with large particle sizes or the trace particles after agglomeration are difficult to be rolled to the positions near the orifice and then are injected into the first cavity due to the fact that the trace particles with large particle sizes or the trace particles after agglomeration are heavy in mass and a synthetic jet flow mode is adopted, and therefore the trace particles with large particle sizes or the trace particles after agglomeration can be remained in the second cavity, and the original flow field structure is prevented from being damaged when the trace particles enter the flow field.

In an embodiment, the exciter has a diaphragm which is part of a wall defining the second cavity.

In one embodiment, the diaphragm resonates with a gas in the second cavity.

In one embodiment, the exciter is a loudspeaker and the diaphragm is a diaphragm within the loudspeaker.

In one embodiment, the particle generator includes:

the tank body is provided with a tank body opening, and the tank wall of the tank body is provided with the airflow inlet and the airflow outlet;

the partition plate is connected with the tank body and used for closing the opening of the tank body, the partition plate and the tank body are enclosed to form the first cavity, a through hole is formed in the partition plate, and the through hole is the jet flow channel;

the sleeve, the said baffle and said tank body of said bush are coaxial, and connect with said baffle, the said baffle closes the said sleeve towards one side opening of said baffle;

the vibrating membrane is arranged on one side, away from the partition plate, of the sleeve, the sleeve is sealed, an opening is formed in one side, away from the partition plate, of the sleeve, and the partition plate, the sleeve and the vibrating membrane enclose the second cavity.

In one embodiment, the sleeve is detachably connected to the partition, or the sleeve is provided with a particle inlet, and the particle generator further comprises a switch operable to open or close the particle inlet.

In an embodiment, the airflow inlet and the airflow outlet are located on the tank wall of the tank body relatively along the axial direction of the tank body, and are arranged in a vertically staggered manner along the axial direction of the tank body.

In one embodiment, the jet inlet of the jet channel, which is communicated with the second cavity, is arranged opposite to the vibrating membrane.

In an embodiment, the airflow inlet and the airflow outlet are oppositely arranged on two sides of the jet outlet of the jet channel communicated with the first cavity.

In an embodiment, the circumferential inner diameter of the fluidic channel is equal to 1 mm.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

FIG. 1 is a schematic view of a structure of a particle generator in an embodiment of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is an exploded view of FIG. 1;

FIG. 4 is a schematic view of the structure of a particle generator according to another embodiment of the present invention;

FIG. 5 is a schematic view showing the structure of a particle generator according to still another embodiment of the present invention.

Description of reference numerals:

1. a tank body; 11. a first cavity; 12. an airflow inlet; 13. an airflow outlet; 2. a sleeve; 21. a second cavity; 3. a speaker; 31. a vibrating membrane; 4. a partition plate; 41. a fluidic channel; 411. a jet inlet; 412. a jet outlet; 5. an upper cavity; 6. a lower cavity; 7. a first conduit; 8. a second conduit; 9. a seal ring; 10. a case body; 101. a piston; 102. and a cylinder.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

In the following description, for the purposes of illustrating various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be understood as an open, inclusive meaning, i.e., as being interpreted to mean "including, but not limited to," unless the context requires otherwise.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings in order to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the essential spirit of the technical solution of the present invention.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise.

In the following description, for the purposes of clearly illustrating the structure and operation of the present invention, directional terms will be used, but terms such as "front", "rear", "left", "right", "outer", "inner", "outer", "inward", "upper", "lower", etc. should be construed as words of convenience and should not be construed as limiting terms.

An embodiment of the present invention, which is a particle generator as shown in fig. 1 to 4, is described below with reference to the accompanying drawings, and includes: the gas flow vibrating diaphragm comprises a first cavity 11, a second cavity 21 and a vibrating diaphragm 31, wherein the first cavity 11 is communicated with the second cavity 21 through a jet flow channel 41, the jet flow channel 41 is generally a fine pipe, a hole or a slit, so that a jet flow can be formed in the first cavity 11, the vibrating diaphragm 31 can vibrate, and when the vibrating diaphragm 31 vibrates, gas in the second cavity 21 can be driven to vibrate, meanwhile, a gas flow inlet 12 and a gas flow outlet 13 are formed in the wall of the cavity defining the first cavity 11, and the gas flow inlet 12 and the gas flow outlet 13 are communicated with the first cavity 11.

Because the particle generator comprises a first cavity, a second cavity communicated with the first cavity through a jet flow channel, and an exciter capable of driving gas in the second cavity to enter the first cavity through the jet flow channel. In actual conditions, generally put into the second cavity with the tracer particle, the gaseous entering first cavity in the driver drive second cavity, and at this in-process, the tracer particle mixes with the gaseous entering first cavity in the second cavity, and the efflux is produced in first cavity in gaseous entering first cavity after the mixing through efflux passageway. Jet refers to a fluid flow in which a fluid is emitted from a nozzle, orifice, or slit (i.e., the above-described fluidic channel) and commingled with surrounding fluids, and the fluid is ejected from the nozzle or orifice, out of the confines of a solid boundary, and flows diffusively in a liquid or gas. Because the efflux has great kinetic energy, consequently the tracer particle who jets can spread fast in whole first cavity, and the tracer particle accomplishes the homogeneous mixing in first cavity promptly. If gas is introduced from the gas flow inlet, the gas uniformly mixed with the trace particles in the first cavity can be slowly blown out from the gas flow outlet and enters the flow field experiment section, so that the particle generator can be also suitable for low-flow-rate experiments.

It should be noted that the exciter is operable to alternately blow gas into the second chamber 21 and generate a discontinuous jet in the first chamber 11 through the jet channel 41, which is called a synthetic jet, and when the exciter is operated, the exciter alternately blows ambient fluid, and the blown fluid forms a vortex ring in the first chamber 11 due to shearing action, and the vortex ring makes the trace particles move in a direction far from the jet channel 41, so that when the exciter generates suction, it is difficult to suck the trace particles in the first chamber 11 back into the first chamber 11, and the synthetic jet has a significant characteristic that only the outward output momentum is zero, and thus is also called a zero-mass jet. Compared with the traditional continuous blowing or suction flow control technology, the synthetic jet has the advantages of simple and compact structure, light weight, low cost, convenient maintenance, no need of additional air source and the like.

Specifically, the actuator includes: the vibrating diaphragm 31, the vibrating diaphragm 31 vibrates and drives the air in the second cavity 21 to vibrate, specifically, in this embodiment, the exciter is the speaker 3, the vibrating diaphragm 31 is a vibrating diaphragm in the speaker 3, sometimes the vibrating diaphragm is also called as a sound diaphragm, and drives the gas in the second cavity 21 to vibrate to generate a synthetic jet, the synthetic jet is a discontinuous jet generated by alternately blowing and sucking the surrounding fluid due to the vibration of the vibrating diaphragm 31, in practice, the trace particles are generally placed on the vibrating diaphragm 31, and the vibration of the vibrating diaphragm 31 helps the trace particles to fall off from the diaphragm into the air to be mixed with the air, so the mixing of the trace particles and the air can be more conveniently performed by using the vibrating diaphragm 31. As shown in fig. 2, since the particle generator includes the first chamber 11, the second chamber 21 communicating with the first chamber 11 through the fluidic channel 41, and the diaphragm 31 capable of driving the gas in the second chamber 21 to vibrate, the trace particles can be put into the second chamber 21 and then the diaphragm 31 is vibrated. The gas in the second cavity 21 is driven to vibrate by the vibration of the vibrating membrane 31 to generate a synthetic jet, the synthetic jet is a discontinuous jet generated by alternately blowing and sucking the surrounding fluid due to the vibration of the vibrating membrane 31, the discontinuous jet can enable the tracer particles in the second cavity 21 to be fully mixed with air, the mixed gas enters the first cavity 11 through the jet channel 41 to generate a jet in the first cavity 11, and the jet refers to a jet flow which is formed by that the fluid is emitted from a pipe orifice, an orifice or a slit (namely the jet channel 41) and is mixed with the surrounding fluid to flow, and the fluid is emitted from the spray pipe or the orifice, is separated from the constraint of a solid boundary and is diffused and flows in the liquid or the gas. Because the efflux has great kinetic energy, consequently the tracer particle who jets can spread fast to whole first cavity 11 in, and the tracer particle accomplishes the homogeneous mixing in first cavity 11 promptly. At this time, if gas is introduced from the gas flow inlet 12, the gas uniformly mixed with the trace particles in the first cavity 11 is slowly blown out from the gas flow outlet 13 and enters the flow field experiment section, so that the particle generator can also be applied to a low flow rate experiment.

In the process, the trace particles are mixed in the first cavity 11 in advance, at this time, as long as the gas is slightly introduced from the gas flow inlet 12, the mixed trace particles will drift out from the gas flow outlet 13, so that the uniform trace particles can be obtained in the low-flow-rate PIV experiment, and in this embodiment, even if the speed of the gas flow outlet 13 is almost zero, the trace particles with better mixing can be obtained to enter the flow field experiment section.

Moreover, because the gas that the mode that makes adopt synthetic efflux will be mixed with the tracer particle blows in first cavity 11, because the tracer particle diameter after the cluster that wets is great, quality and volume are great, the followability of particle is relatively poor, stay second cavity lower floor, consequently adopt synthetic efflux's mode, hardly blow in first cavity 11 with the particle of reunion, consequently the tracer particle that the particle diameter is great or the tracer particle after the cluster can stay in second cavity 21, avoid it to destroy original flow field structure in getting into the flow field.

In addition, the circumferential inner diameter of the jet flow channel 41 is recommended to be larger than or equal to 1mm, and the common tracer particles in the air flow field are generally smaller than 10 μm, so when the jet flow channel 41 is equal to 1mm, 100% of agglomerate particles with the size of more than 1mm can be filtered, but if the agglomerate particles with the size of hundreds of μm exist, most of agglomerate particles cannot be carried out by the jet flow because the following performance of large particle particles is poor. Thereby making the particle size of the trace particles more uniform. It should be noted that in some embodiments, the diameter of the fluidic channel may be selected to vary its size depending on the volume of the second chamber, with the smallest possible size being selected to increase the flow rate and reynolds number of the outlet jet, but too small may cause particle blockage.

In addition, as shown in fig. 2, the fluidic channel 41 is provided with a fluidic inlet 411 communicating with the second cavity 21, and the fluidic inlet 411 is disposed opposite to the diaphragm 31.

In addition, as shown in fig. 2 and 3, in the present embodiment, the particle generator further includes a driving device, the driving device drives the diaphragm 31 to vibrate, the combined device of the diaphragm 31 and the driving device is a loudspeaker 3, that is, the diaphragm 31 is the diaphragm 31 on the loudspeaker 3, and the loudspeaker 3 can be directly purchased in the market, so that the overall structure of the particle generator becomes simple and the cost is low.

Of course, in some embodiments, the exciter may be selected from piezoelectric film vibration, piston vibration, polyvinylidene fluoride film vibration, and the like, in addition to the speaker 3, without departing from the scope of the present invention.

In addition, the diaphragm 31 and the gas in the second cavity 21 generate resonance to adjust the working frequency of the loudspeaker 3, under the same power, the airflow speed ejected from the jet channel 41 to the first cavity 11 is different for different working frequencies, and a resonance frequency exists, and the airflow speed ejected from the jet channel 41 is the maximum when the loudspeaker 3 works at the resonance frequency, so that the mixing effect of the tracer particles is the best. If the resonant frequency is 100Hz, it represents that the gas with trace particles is ejected from the jet channel 41 100 times per second, so that it is uniformly mixed in the first cavity 11. The larger the working power of the loudspeaker 3 is, the more tracer particles are ejected, the higher the concentration of the tracer particles flowing out of the airflow outlet 13 at the same flow speed is, and the particle generator can be adjusted to the working condition required by people by adjusting the power of the loudspeaker 3.

In addition, as shown in fig. 4, the jet flow channel 41 has a jet flow outlet 412 communicated with the first cavity 11, and the gas flow inlet 12 and the gas flow outlet 13 are located at both sides of the jet flow outlet 412, so that the tracer particles ejected from the jet flow outlet 412 can be fully mixed into the gas flow entering from the gas flow inlet 12 and enter the experimental section of the flow field from the gas flow outlet 13, thereby increasing the concentration of the tracer particles entering the experimental section of the flow field.

In addition, as shown in fig. 1 to 3, the particle generator specifically further includes: a tank body 1, a clapboard 4 and a sleeve 2, wherein, the tank body 1 is provided with an opening of the tank body 1, the wall of the tank body 1 is provided with an airflow inlet 12 and an airflow outlet 13, the clapboard 4 is connected with the tank body 1, and the opening of the tank body 1 is sealed, in particular, the clapboard 4 can be connected with the tank body 1 through a bolt, of course, the glue can also be used, the cavity enclosed by the partition board 4 and the tank body 1 is the first cavity 11, and the through hole is arranged on the partition board 4, the through hole is the jet flow channel 41, the sleeve 2, the partition plate 4 and the tank body 1 are coaxially arranged and are connected with the partition plate 4, the partition 4 closes the opening of the sleeve 2 on the side facing the partition 4, and the diaphragm 31 is arranged on the side of the sleeve 2 remote from the partition 4, and the opening of the sleeve 2 at the side far from the partition plate 4 is sealed, and the area enclosed by the partition plate 4, the sleeve 2 and the vibrating membrane 31 is the second cavity 21.

Specifically, the sleeve 2 is detachably connected to the partition plate 4, or the sleeve 2 is provided with a particle inlet, and when the sleeve 2 is provided with a particle inlet, the particle generator further includes a switch capable of opening or closing the particle inlet, and the switch may be a plug or a cover.

In this embodiment, the sleeve 2 is detachably connected to the partition plate 4, before operation, the sleeve 2 and the partition plate 4 can be detached, the trace particles are put into the second cavity 21, preferably, the trace particles can be put on the diaphragm 31, and then the sleeve 2 and the partition plate 4 are connected, so that the speaker 3 can be turned on, the diaphragm 31 vibrates, and meanwhile, if there is a particle inlet, the trace particles can be put into the second cavity 21 through the particle inlet.

In addition, as shown in fig. 2 and 3, a first pipeline 7 and a second pipeline 8 are further connected to the tank 1, an inlet of the first pipeline 7, which is communicated with the first cavity 11 of the tank 1, is an airflow inlet 12, an outlet of the second pipeline 8, which is communicated with the first cavity 11 of the tank 1, is an airflow outlet 13, the second pipeline 8 can be communicated with the flow field experimental part, and the first pipeline 7 can be communicated with an air compressor.

As shown in fig. 2 and 3, the gas inlet 12 and the gas outlet 13 are oppositely disposed on the tank 1, and are located on both sides of the jet outlet 412, and are staggered up and down.

In addition, as shown in fig. 3, in order to increase the sealing performance between the first cavity 11 and the second cavity 21, a sealing ring 9 may be added between the tank 1 and the partition plate 4, and the sealing rings 9 may be added between the partition plate 4 and the sleeve 2, and between the sleeve 2 and the speaker 3.

Of course, it should be noted that in some embodiments, as shown in fig. 4, the particle generator may also be an elongated box 10, the box 10 has a cavity therein, and a partition plate 4 is disposed in the box 10, and the partition plate 4 divides the cavity of the box 10 into an upper cavity 5 and a lower cavity 6. The lower cavity 6 is provided with a vibrating membrane 31, and the vibrating membrane 31 closes the downward opening of the can body 1, so that the vibrating membrane 31 forms a cavity wall for defining the lower cavity 6. Meanwhile, the box body 10 is also provided with an airflow inlet 12 and an airflow outlet 13 which are both communicated with the upper cavity 5, the airflow inlet is communicated with the first pipeline 7, and the airflow outlet 13 is communicated with the second pipeline 8. The upper chamber 5 is the first chamber 11, the lower chamber 6 is the second chamber 21, and the partition plate 4 is provided with a through hole or a narrow slit, which is the jet flow channel 41, for placing trace particles into the lower chamber 6.

In addition, it should be noted that when the partition plate 4 divides the chamber into the upper chamber 5 and the lower chamber 6, the speaker may be disposed in the lower chamber 6, as shown in fig. 5, the actuator may further include a piston 101 and a cylinder 102, the piston 101 may be slidably disposed in the lower chamber 6, and the gas mixed with the trace particles in the lower chamber 6 may be sent into the upper chamber 5 through the jet flow passage 41 by the up-and-down movement of the piston 101. The piston 101 can be coaxially and fixedly connected with a mandril of the cylinder 102, and the cylinder 102 pushes the piston to move up and down. Of course, similar moving parts may be substituted in addition to the piston 101 without departing from the scope of the present invention.

Of course, in addition to the above structure, the particle generator may be two sealed cases, the two sealed cases are communicated with each other through a thin tube, the vibrating membrane 31 is disposed in one sealed case, and other modifications may be made to the structure of the particle generator according to actual needs without departing from the scope of the present invention.

In the present case, the speaker 3 is selected as a driving member for driving the air in the second cavity 21 to vibrate, and the speaker 3 converts the input electric energy into the kinetic energy of the vibrating member, that is, into the vibration of the diaphragm 31. Change the pressure in the second cavity 21 during the vibration of 3 diaphragms 31 of speaker, along with 3 diaphragms 31 vibration of speaker, there is the air current from jet channel 41 blowout, be equipped with an amount of tracer particle in the second cavity 21, so the air current from jet channel 41 blowout also has the tracer particle, because of jet channel 41 is less, and large granule air current following nature is relatively poor, consequently only less granule can follow the air current and spray through jet channel 41, synthetic jet because of spouting has great kinetic energy, the tracer particle who spouts can spread to whole first cavity 11 fast, the homogeneous mixing of tracer particle completion in first cavity 11 promptly. At this time, if gas is introduced from the first pipe 7, the gas in the first chamber 11, in which the trace particles are uniformly mixed, is slowly blown out from the second pipe 8.

It can be seen from the above that the structure of the present invention is greatly simplified, so that the manufacturing cost is greatly reduced, mainly the synthetic jet principle is adopted for particle mixing, and the speaker 3 is adopted as the synthetic jet actuator.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.

Claims

1. A particle generator, comprising:

an actuator in communication with the second chamber and operable to drive gas within the second chamber through the fluidic channel into the first chamber;

wherein the tracer particles are operably disposed within a second chamber and the actuator is operable to drive gas within the second chamber to vibrate to produce the synthetic jet.

2. The particle generator of claim 1, wherein the actuator has a diaphragm, the diaphragm being a portion of a wall defining the second chamber.

3. The particle generator of claim 2, wherein the diaphragm resonates with a gas in the second cavity.

4. The particle generator of claim 2 wherein the actuator is a speaker and the diaphragm is a diaphragm within the speaker.

5. The particle generator of claim 2, wherein the particle generator comprises:

the sleeve, the baffle and the tank body are coaxially arranged and are connected with the baffle, and the baffle seals an opening of the sleeve facing to one side of the baffle;

6. The particle generator of claim 5, wherein the sleeve is removably coupled to the barrier or the sleeve defines a particle inlet, and further comprising a switch operable to open or close the particle inlet.

7. The particle generator of claim 6, wherein the airflow inlet and the airflow outlet are located on the tank wall of the tank body along the axial direction of the tank body, and are staggered up and down along the axial direction of the tank body.

8. The particle generator of claim 2 wherein the fluidic inlet of the fluidic channel in communication with the second chamber is disposed opposite the diaphragm.

9. The particle generator of claim 1, wherein the airflow inlet and the airflow outlet are oppositely disposed on two sides of the jet outlet of the jet channel communicating with the first cavity.

10. The particle generator of claim 1 wherein the jet channel has a circumferential inner diameter equal to 1 mm.