A method and device for synchronously measuring gas-solid two-phase velocity field

Abstract

The present invention belongs to the field of gas-solid two-phase flow measurement, and specifically relates to a method and device for synchronously measuring the velocity field of a gas-solid two-phase flow, wherein the device includes a particle generator and a high-enthalpy supersonic airflow supply section and a windowed test section arranged in sequence; the high-enthalpy supersonic airflow supply section is used to inject a high-enthalpy supersonic airflow generated by the combustion and heating of a fuel carrying nanoparticles into the windowed test section, and the nano-sized particles act as airflow tracer particles and follow the flow of the airflow; the particle generator includes a roller brush mechanism, a particle output structure, and n groups of particle supply mechanisms, and also includes a measurement component for measuring the gas-solid two-phase flow in the windowed test section. The particle generator of the present invention achieves efficient, stable, and uniform output of micron-sized particle flow, and has flexibility. It can provide particles of various sizes and / or materials independently, simultaneously, or in a set order, and can accurately control the mixing ratio, providing different test conditions for gas-solid two-phase flow measurement.

Description

Technical Field

[0001] The present invention belongs to the field of gas-solid two-phase flow measurement, and in particular relates to a gas-solid two-phase velocity field synchronous measurement method and a measuring device. Background Art

[0002] High-enthalpy supersonic gas-solid two-phase flow carrying micron-sized particles refers to a complex flow phenomenon in which the gas medium is in a high total enthalpy state, with a flow velocity exceeding the local speed of sound (Ma>1), and transports micron-sized solid particles. Significant momentum, energy, and possibly mass exchange occurs between the gas and particle phases. This is a typical flow state in advanced solid propulsion systems such as solid rocket motors, solid rocket scramjets, and powder ramjets, as well as in industrial processing systems such as supersonic spraying. This process is characterized by extremely small particle size, extremely high total temperature (>1000K), extremely high velocity (>1000m / s), and extremely complex flow, posing significant challenges to its observation and study. Research on the mechanisms and models of supersonic gas-solid two-phase flow is still in its infancy, and it is difficult to scientifically guide engineering practice. At the same time, facing the need for thrust control in multiple solid-state propulsion engines, various high-enthalpy supersonic gas-solid two-phase flow conditions (including inflow total temperature, total pressure, velocity, solid particle mass flow rate, particle size, etc.) may occur during different engine operation stages. However, the research on supersonic gas-solid two-phase flow processes under variable operating conditions remains a blank. Therefore, a mature method and device for synchronous measurement of gas-solid two-phase velocity fields is needed to meet these requirements.

[0003] Against this backdrop, some scholars have proposed a real-time measurement system and method for gas-solid two-phase flow fields. For example, patent application CN102313684A provides a real-time measurement system and method for gas-solid two-phase flow fields, which utilizes two gas-phase digital high-speed cameras and one solid-phase digital high-speed camera to achieve real-time measurement of the two-phase flow field. However, the experimental conditions involved in this method involve a low incoming flow velocity, slow movement of the gas-solid two-phase flow, and lack the characteristics of high total temperature, high flow velocity, and micron-sized solid particles. Clearly, these experimental conditions are unsuitable for the study of variable-condition, high-enthalpy, supersonic gas-solid two-phase flow carrying micron-sized particles. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a gas-solid two-phase velocity field synchronous measurement method and measurement device with multi-operating condition adjustment.

[0005] The present invention provides a gas-solid two-phase velocity field synchronous measurement device, comprising a particle generator and a high enthalpy supersonic airflow supply section and a windowed experimental section arranged in sequence;

[0006] The high-enthalpy supersonic airflow supply section is used to inject high-enthalpy supersonic airflow generated by the combustion and heating of the nanoparticle-carrying fuel into the windowed experimental section. The nanoparticles act as airflow tracer particles and follow the airflow.

[0007] The particle generator includes a roller brush mechanism, a particle output structure and n groups of particle supply mechanisms. The roller brush mechanism includes a cylinder, a brush body rotatably arranged in the cylinder, and a rotary drive mechanism for driving the brush body to rotate.

[0008] An opening I is provided on the wall surface of the cylinder, and the particle output structure includes an air inlet pipe I and an output pipe that are tangent to and co-linear with the outer side of the brush body. The particle output structure also includes an air inlet pipe II whose extension line passes through the axis of the brush body. The outlet of the air inlet pipe I, the inlet of the output pipe, and the outlet of the air inlet pipe II are interconnected at the position of opening I, and the inlets of the air inlet pipe I and the air inlet pipe II are connected to the air supply device, and the outlet of the output pipe is connected to the upstream of the windowed experimental section;

[0009] The cylinder is provided with n openings II below the horizontal symmetry plane. The particle supply mechanism includes a particle receiving chamber connected to the opening II and a driving mechanism for driving the cavity volume of the particle receiving chamber to decrease. When the cavity volume of the particle receiving chamber decreases, micron-sized particles contact the brush body from the opening II. n is greater than or equal to 2, and the micron-sized particles in the n particle receiving chambers are of different sizes and / or materials. The n driving mechanisms operate independently, simultaneously, or in a set sequence.

[0010] The invention also includes a measurement component for measuring the gas-solid two-phase flow in the windowed experimental section.

[0011] Furthermore, the opening I is provided at an end of the cylinder away from the particle supply mechanism.

[0012] Furthermore, the inlets of the air intake pipe I and the air intake pipe II are connected to each other and then connected to the air supply device.

[0013] Furthermore, the driving mechanism includes a linear driving mechanism and a base plate arranged on the output end of the linear driving mechanism, and the base plate and the opening II are arranged opposite to each other.

[0014] Furthermore, the particle supply mechanism is provided with several groups along the arc direction of the cylinder;

[0015] And / or, the particle supply mechanism is provided in a plurality of groups along the axial direction of the cylinder.

[0016] Furthermore, the high enthalpy supersonic airflow supply section includes a fuel storage tank, an air heater, and a Laval nozzle arranged in sequence;

[0017] The fuel tank is used to store liquid fuel carrying nano-scale particles;

[0018] The air heater includes a mixing chamber and an air inlet connected to the mixing chamber, and the fuel storage tank is connected to the mixing chamber;

[0019] The inlet of the Laval nozzle is connected to the mixing chamber, and the outlet is connected to the windowed test section.

[0020] Furthermore, the mixing chamber is also connected to an oxygen inlet.

[0021] Furthermore, the measurement component includes a synchronous controller, and a pulse laser and a double-exposure CCD camera connected to the synchronous controller. The pulse laser and the double-exposure CCD camera are arranged on opposite sides of the windowed experimental section.

[0022] The present invention also provides a method for synchronously measuring a gas-solid two-phase velocity field, using the above-mentioned gas-solid two-phase velocity field synchronous measurement device, comprising the following steps:

[0023] S1, a high-enthalpy supersonic airflow with nano-sized particles flows into the windowed experimental section, and the nano-sized particles act as airflow tracer particles and follow the airflow in the windowed experimental section;

[0024] S2, the particle generator injects micron-sized particles upstream into the windowed experimental section;

[0025] S3, the measurement component captures the scattered light of micron-sized particles and nano-sized particles, and separates the scattered light images of micron-sized particles and airflow tracer particles based on the particle image separation algorithm, and obtains the two-dimensional velocity field information of micron-sized particles and gas phase flow field at the same time through the cross-correlation algorithm or particle tracking algorithm.

[0026] Furthermore, in step S2, the particle generators work independently, simultaneously, or in a set order as needed to provide micron-sized particles with inconsistent sizes and / or inconsistent materials to the upstream of the windowed experimental section.

[0027] The beneficial effect of the present invention is that the gas-solid two-phase velocity field synchronous measurement device provided by the present invention has a particle generator that achieves the effects of enhanced mixing and efficient flushing of the brush body through an innovative dual-path air intake design of the air intake pipe I and the air intake pipe II. In addition, combined with the independent controllable drive of the multi-particle supply mechanism, it successfully solves the pain points of traditional particle generators in terms of particle transport efficiency, residue control, single particle type and mixing interference. It achieves efficient, stable and uniform output of micron-level particle flow, and has extremely high flexibility. It can provide particles of various sizes and / or materials independently, simultaneously or in a set order, and can accurately control the mixing ratio. These characteristics significantly improve the experimental accuracy, stability, repeatability and research capabilities of the entire gas-solid two-phase velocity field synchronous measurement device, such as the experimental range and experimental depth. It solves the problem that the supersonic gas-solid two-phase flow process with variable working conditions in engines currently using different solid propellants or powdered fuels is difficult to accurately and efficiently test.

[0028] The synchronous measurement device for gas-solid two-phase velocity field is proposed to address the problem that it is impossible to simultaneously achieve synchronous measurement of particle velocity field and gas phase velocity field during the current research on variable-condition high-enthalpy supersonic gas-solid two-phase flow carrying micron-sized particles. Nano-sized particles are sown in the high-enthalpy supersonic incoming flow as tracer particles of the gas phase flow field, and micron-sized particles are injected into the incoming flow as solid particles in the form of a transverse jet through a particle generator to form a high-enthalpy gas-solid two-phase incoming flow carrying micron-sized particles. The parameter control of the high-enthalpy supersonic airflow supply section and the design of the particle generator are used to realize real-time changes in the supersonic gas-solid two-phase flow conditions during the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Attachment Figure 1 Schematic diagram of the structure of the gas-solid two-phase velocity field synchronous measurement device of the present invention;

[0030] Attachment Figure 2 Schematic diagram of the structure of the particle generator of the present invention;

[0031] Attachment Figure 3 Schematic diagram of image separation of micron-sized particles and nano-sized particles in gas-solid two-phase flow in the present invention.

[0032] In the figure, 1-air heater; 2-fuel storage tank; 3-Laval nozzle; 4-particle generator; 41-rolling brush mechanism; 411-cylinder; 412-brush body; 413-opening I; 414-opening II; 42-particle output structure; 421-inlet pipe I; 422-output pipe; 423-inlet pipe II; 43-particle supply mechanism; 431-particle accommodating chamber; 432-drive mechanism; 4321-linear drive mechanism; 4322-base plate; 5-windowed experimental section; 6-pulsed laser; 7-synchronous controller; 8-double-exposure CCD camera; 9-control system. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0036] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; it can mean mechanical connection, electrical connection, physical connection, or wireless communication connection; it can mean direct connection or indirect connection through an intermediate medium; it can mean internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] As attached Figure 1 -Attached Figure 3 As shown, the present invention provides a gas-solid two-phase velocity field synchronous measurement device, comprising a particle generator 4 and a high enthalpy supersonic airflow supply section and a windowed experimental section 5 arranged in sequence;

[0039] The high-enthalpy supersonic airflow supply section is used to inject a high-enthalpy supersonic airflow with nano-sized particles into the windowed experimental section 5. The airflow flows into the windowed experimental section 5 at a high speed, and the nano-sized particles follow the airflow as airflow tracer particles.

[0040] The particle generator 4 includes a roller brush mechanism 41, a particle output structure 42, and an n-group particle supply mechanism 43. The roller brush mechanism 41 includes a cylinder 411, a brush body 412 rotatably disposed in the cylinder 411, and a rotary drive mechanism for driving the brush body 412 to rotate. The rotary drive mechanism can be a motor.

[0041] An opening I413 is provided on the wall of the cylinder 411, and the particle output structure 42 includes an air inlet pipe I421 and an output pipe 422 that are tangent to the outer side of the brush body 412 and arranged in the same line. The particle output structure 42 also includes an air inlet pipe II423 whose extension line passes through the axis of the brush body 412, that is, the direction of the air inlet pipe II423 is perpendicular to the direction of the air inlet pipe I421, and the outlet of the air inlet pipe I421, the inlet of the output pipe 422 and the outlet of the air inlet pipe II423 are connected to each other at the position of the opening I413. Preferably, the outlet of the air inlet pipe I421, the inlet of the output pipe 422, the outlet of the air inlet pipe II423 and the opening I413 are enclosed to form The air collecting chamber, and the inlets of the air inlet pipe I 421 and the air inlet pipe II 423 are connected to the air supply device. In order to output the micron-sized particles through the output pipe 422 to the upstream of the windowed experimental section 5, the air supply device is used to supply fluidizing gas. The outlet of the output pipe 422 is connected to the upstream of the windowed experimental section 5. Specifically, the air supply device supplies air to the air inlet pipe I 421 and the air inlet pipe II 423, which enter the air collecting chamber from the side and vertical directions of the opening I 413 respectively. At this time, the two-way air intake can increase the flow complexity in the air collecting chamber, thereby enhancing the mixing process of the micron-sized particles and the fluidizing gas, and making the gas-solid two-phase flow output from the output pipe 422 more uniform. Among them, the lateral air inlet pipe I 421 can ensure that the gas-solid two-phase airflow after the fluidizing gas and the micron-sized particles are mixed can efficiently enter the input pipe 422, and the fluidizing gas provided by the vertical air inlet pipe II 423 (relative to the air inlet pipe I 421) can produce a flushing effect on the brush body 412, and can flush the micron-sized particles entrained on the brush body 412 into the gas collecting cavity, thereby effectively reducing the residual particles on the brush body 412, improving the particle transport efficiency and the situation of excessive particles remaining in the device in the later stage of operation, thereby improving the supply performance of the gas-solid two-phase flow, and when transporting n kinds of micron-sized particles with inconsistent sizes and / or inconsistent materials in a set order, it can reduce the mutual interference of the n kinds of micron-sized particles with inconsistent sizes and / or inconsistent materials, thereby improving the accuracy and stability of the experiment;

[0042] The cylinder 411 is provided with n openings II 414 below the horizontal symmetry plane. The particle supply mechanism 43 includes a particle receiving chamber 431 in communication with the opening II 414 and a driving mechanism 432 for driving the cavity volume of the particle receiving chamber 431 to decrease. Each particle receiving chamber 431 is used to accommodate micron-sized particles of uniform size and / or material. When the cavity volume of the particle receiving chamber 431 decreases, the micron-sized particles are squeezed and rise. After rising, they come into contact with the brush body 412 through the opening II 414 and are finally carried away by the rotating brush body 412 to the gas collecting chamber.

[0043] Wherein, n is greater than or equal to 2, and the micron-sized particles in the n particle-holding cavities 431 are of inconsistent sizes and / or materials, and the n driving mechanisms 432 operate independently, simultaneously, or in a set order. When the n driving mechanisms 432 operate independently, micron-sized particles of one size or one material are tested at a time. When the n driving mechanisms 432 operate simultaneously, micron-sized particles of various sizes and / or various materials can be tested, and the content ratio of micron-sized particles of various sizes and / or various materials can be adjusted by controlling the driving amplitude of the driving mechanisms 432. When the n driving mechanisms 432 operate in a set order, the supply of micron-sized particles of various sizes and / or various materials can be tested in a specific or random order.

[0044] Among them, all openings II 414 are set below the horizontal symmetry plane of the cylinder 411, which can prevent the micron-sized particles in the particle accommodating cavity 431 from falling into the opening II 414 by gravity and then entering the brush body 412, thereby avoiding uncontrolled output of the micron-sized particles.

[0045] The gas-solid two-phase velocity field synchronous measurement device also includes a measurement component for measuring the gas-solid two-phase flow in the windowed experimental section 5 .

[0046] The synchronous gas-solid two-phase velocity field measurement device provided by the present invention has a particle generator 4 that achieves the effects of enhanced mixing and efficient flushing of the brush body 412 through an innovative dual-path air intake design of intake pipe I 421 and intake pipe II 423. In addition, combined with the independent controllable drive of the multi-particle supply mechanism 43, it successfully solves the pain points of traditional particle generators in terms of particle transport efficiency, residue control, single particle type, and mixing interference. It achieves efficient, stable, and uniform output of micron-level particle flow and has extremely high flexibility. It can provide particles of various sizes and / or materials independently, simultaneously, or in a set order, and can accurately control the mixing ratio. These characteristics significantly improve the experimental accuracy, stability, repeatability, and research capabilities of the entire synchronous gas-solid two-phase velocity field measurement device, such as the experimental range and experimental depth. It solves the problem that the supersonic gas-solid two-phase flow process with variable operating conditions in engines using different solid propellants or powdered fuels is difficult to accurately and efficiently test.

[0047] The synchronous measurement device for gas-solid two-phase velocity field is proposed to address the problem that it is impossible to simultaneously achieve synchronous measurement of particle velocity field and gas phase velocity field during the current research on variable-condition high-enthalpy supersonic gas-solid two-phase flow carrying micron-sized particles. Nano-sized particles are sown in the high-enthalpy supersonic incoming flow as tracer particles of the gas phase flow field, and micron-sized particles are injected into the incoming flow as solid particles in the form of a transverse jet through the particle generator 4 to form a high-enthalpy gas-solid two-phase incoming flow carrying micron-sized particles. The parameter control of the high-enthalpy supersonic airflow supply section and the design of the particle generator 4 are used to achieve real-time changes in the supersonic gas-solid two-phase flow conditions during the experiment.

[0048] In one embodiment, opening I 413 is located at the end of the cylinder 411 facing away from the particle supply mechanism 43. This embodiment allows the vertical airflow from the air inlet pipe II 423 to more directly and fully flush the top surface of the rotating brush body 412, effectively stripping attached particles. Furthermore, this location is located away from the particle supply mechanism 43, allowing the particles to naturally rise and converge into the plenum chamber under the action of the airflow, reducing sidewall accumulation, further optimizing particle transport efficiency, and reducing residual particles.

[0049] In one embodiment, the inlets of air intake pipe I 421 and air intake pipe II 423 are connected to each other and then connected to an air supply device. Preferably, air intake pipe I 421, air intake pipe II 423 and the air supply device are connected by a tee pipe, thereby achieving one air supply device connecting two air intake pipes, reducing the number of air supply devices.

[0050] In one embodiment, the driving mechanism 432 includes a linear driving mechanism 4321 and a base plate 4322 arranged on the output end of the linear driving mechanism 4321, wherein the linear driving mechanism 4321 can be a cylinder, a hydraulic cylinder or an electric cylinder, and the base plate 4322 and the opening II 414 are arranged relative to each other. In this embodiment, a cylinder with openings at both ends is also included, and the base plate 4322 is slidably arranged in the cylinder. The base plate 4322 and the cylinder are enclosed to form a particle accommodating chamber 431. At this time, the upper end of the cylinder is connected to the opening II 414. Preferably, the upper end of the cylinder has an arc-shaped cross-section and is connected to the opening II 414. In this embodiment, the base plate 4322 moves toward the opening II 414, reducing the volume of the particle accommodating chamber 431, thereby causing the particles in the particle accommodating chamber 431 to face the opening II 414.

[0051] In one embodiment, the particle supply mechanism 43 is provided with several groups along the arc direction of the cylinder 411;

[0052] And / or, a plurality of particle supply mechanisms 43 are provided along the axis direction of the cylinder 411. In this embodiment, more particle supply mechanisms 43 can be provided, thereby increasing the test breadth of the experiment.

[0053] In one embodiment, the high enthalpy supersonic airflow supply section includes a fuel storage tank 2, an air heater 1 and a Laval nozzle 3 arranged in sequence;

[0054] The fuel tank 2 is used to store liquid fuel containing nano-sized particles, such as alcohol. In a specific embodiment, an alcohol suspension containing nano-sized particles prepared by adding an appropriate amount of nano-sized particles to alcohol is stored in the fuel tank 2.

[0055] The air heater 1 includes a mixing chamber and an air inlet connected to the mixing chamber. A fuel storage tank 2 is connected to the mixing chamber. Liquid fuel in the form of nanoparticles enters the mixing chamber and mixes with air injected through the air inlet, facilitating ignition. The air heater 1 is configured to inject liquid fuel into the mixing chamber, where it burns and heats the air, generating high total temperature and pressure air.

[0056] The inlet of the Laval nozzle 3 is connected to the mixing chamber, and the outlet is connected to the windowed experimental section 5. The Laval nozzle 3 can accelerate the generation of a high-enthalpy supersonic flow carrying nano-sized particles.

[0057] In one embodiment, the mixing chamber is further connected to an oxygen inlet to provide oxygen into the mixing chamber.

[0058] In one embodiment, a valve and flowmeter are installed between the fuel storage tank 2 and the mixing chamber, and valves and flowmeters are also installed at the oxygen inlet and the air inlet. All three sets of valves and flowmeters are connected to a control system 9. In this embodiment, the control system 9 controls the mass flow rate of each component as needed during the experiment, thereby controlling the total temperature, total pressure, and flow rate of the supersonic incoming flow, and achieving changes in the operating conditions of the high-enthalpy supersonic incoming flow carrying nanoparticles.

[0059] In one embodiment, the measurement component includes a synchronous controller 7 and a pulse laser 6 and a double-exposure CCD camera 8 connected to the synchronous controller 7. The pulse laser 6 and the double-exposure CCD camera 8 are respectively arranged on the left and right sides or the upper and lower sides of the windowed experimental section 5.

[0060] In this embodiment, only one pulse laser 6 with a fixed wavelength and one double-exposure CCD camera 8 are used in the particle image data acquisition process, and the optical path is simple to construct and the cost is low.

[0061] In this embodiment, when the gas-solid two-phase fluid flows through the windowed experimental section 5, the pulsed laser 6 illuminates the flow field with laser sheet light, and the synchronization controller 7 controls the double-exposure CCD camera 8 to synchronously trigger and capture the scattered light of micron-sized particles and airflow tracer particles in the laser sheet light plane. Based on the double-exposure principle, multiple pairs of time-correlated particle scattered light images are obtained. The above-mentioned collected images are then post-processed, and the particle image separation algorithm based on brightness threshold and particle size is used to separate the micron-sized particle image from the background nanoparticle image in the image. Figure 3 Then, a cross-correlation algorithm or a particle tracking algorithm is used to process two consecutive time-correlated micron-sized particle scattering images and airflow tracer particle scattering images, respectively. The velocity of the airflow tracer particles is used to represent the velocity of the local gas phase flow field. Ultimately, the instantaneous two-dimensional velocity field information of micron-sized particles and gas phase fluid in supersonic gas-solid two-phase flow under variable working conditions is simultaneously obtained.

[0062] Specifically, the method for separating and calculating the gas-solid two-phase velocity field first uses a particle image separation algorithm based on brightness thresholds and particle size algorithms to separate the micron-sized particles and the airflow tracer particle images captured by the camera. A cross-correlation algorithm or a particle tracking algorithm is then used to process two consecutive time-correlated micron-sized particle scattering images and airflow tracer particle scattering images, respectively. The velocity of the airflow tracer particles is used to represent the velocity of the local gas phase flow field. Ultimately, the instantaneous two-dimensional velocity field information of the micron-sized particles and the gas phase fluid in the supersonic gas-solid two-phase flow is simultaneously obtained. This method has the advantage of being able to separate and obtain the velocity field of the gas-solid two-phase flow at the same time.

[0063] The present invention also provides a method for synchronously measuring a gas-solid two-phase velocity field, using the above-mentioned gas-solid two-phase velocity field synchronous measurement device, comprising the following steps:

[0064] S1, a high-enthalpy supersonic airflow with nano-sized particles flows into the windowed experimental section 5, and the nano-sized particles act as airflow tracer particles and follow the airflow in the windowed experimental section 5;

[0065] In step S2, particle generator 4 injects micron-sized particles upstream of windowed experimental section 5, preferably in a transverse direction, to enhance mixing of the micron-sized particles with the airflow, forming a high-enthalpy supersonic gas-solid two-phase flow carrying the micron-sized particles, simulating real-world operating conditions. This satisfies the need for disseminating airflow tracer particles while maintaining the generation of high total temperature and high total pressure incoming flow.

[0066] S3, the measurement component captures the scattered light of micron-sized particles and nano-sized particles, and separates the scattered light images of micron-sized particles and airflow tracer particles based on the particle image separation algorithm, and obtains the two-dimensional velocity field information of micron-sized particles and gas phase flow field at the same time through the cross-correlation algorithm or particle tracking algorithm.

[0067] In one embodiment, in step S2, the particle generator 4 operates independently, simultaneously, or in a set order as needed to provide micron-sized particles with inconsistent sizes and / or inconsistent materials to the upstream of the windowed experimental section 5.

[0068] In this embodiment, during the experiment, the control of the operating parameters of the air heater 1 and particle generator 4, as well as the speed and sequence of the particle generator 4's various particle supply mechanisms 43 and drive mechanisms 432, can be used to alter parameters such as the incoming flow's total temperature, total pressure, gas mass flow rate, and micron-sized particle flow rate, particle size, and material, thereby achieving real-time changes in the operating conditions of high-enthalpy supersonic gas-solid two-phase flow. During the experiment, for a three-component air heater system using liquid fuel (alcohol in this example), air, and oxygen, the mass flow rates of each component were controlled as needed via a flow controller and programmable control system 9 to alter the incoming flow conditions. Furthermore, the particle generator 4 utilizes a multi-particle supply mechanism 43, capable of simultaneously storing multiple batches of particles with varying particle sizes, density ranges, and materials. By individually controlling the propulsion speed and sequence of the drive mechanisms 432, multiple particles can be supplied in a specific order or simultaneously, thereby achieving control over the solid particle conditions in the supersonic airflow.

[0069] This method for synchronously measuring the gas-solid two-phase velocity field sows airflow tracer particles in a high-enthalpy supersonic gas-solid two-phase flow carrying micron-sized particles to trace the movement process of the gas phase flow field. Based on the component flow control of the air heater 1 and the design of the particle generator 4, the gas-solid two-phase supply performance is improved and the supersonic gas-solid two-phase flow conditions are adjusted in real time. Based on the principle of planar laser scattering imaging, a pulsed laser 6 and a double-exposure CCD camera 8 are used to capture the scattered light of micron-sized particles and nanometer-sized tracer particles, and the scattered light images of the micron-sized particles and the airflow tracer particles are separated based on the particle image separation algorithm. The two-dimensional velocity field information of the micron-sized particles and the gas phase flow field at the same time is obtained through a cross-correlation algorithm or a particle tracking algorithm.

[0070] The present gas-solid two-phase velocity field synchronous measurement method is applicable to high-enthalpy supersonic gas-solid two-phase flow processes, and the velocity measurement effect will not be affected by excessively high gas-solid two-phase temperature and pressure.

[0071] This synchronous measurement method for the gas-solid two-phase velocity field, based on the principles of particle image velocimetry and particle tracking velocimetry, can obtain the two-dimensional velocity field results of the gas and solid phases in a certain plane in supersonic gas-solid two-phase flow at the same time. It has a large measurement range, is suitable for strong transient processes, and can realize the separation of gas-solid two-phase velocities.

[0072] The above description is merely an embodiment and does not limit the present invention in any way. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes, modifications, or modifications to the technical solution of the present invention into equivalent embodiments with equivalent changes using the technical content disclosed above. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A gas-solid two-phase velocity field synchronous measurement device, characterized in that: It includes a particle generator and a high enthalpy supersonic airflow supply section and a windowed experimental section which are arranged in sequence; The high-enthalpy supersonic airflow supply section is used to inject high-enthalpy supersonic airflow generated by the combustion and heating of the nanoparticle-carrying fuel into the windowed experimental section. The nanoparticles act as airflow tracer particles and follow the airflow. The particle generator includes a roller brush mechanism, a particle output structure and n groups of particle supply mechanisms. The roller brush mechanism includes a cylinder, a brush body rotatably arranged in the cylinder, and a rotary drive mechanism for driving the brush body to rotate. An opening I is provided on the wall surface of the cylinder, and the particle output structure includes an air inlet pipe I and an output pipe that are tangent to and co-linear with the outer side of the brush body. The particle output structure also includes an air inlet pipe II whose extension line passes through the axis of the brush body. The outlet of the air inlet pipe I, the inlet of the output pipe, and the outlet of the air inlet pipe II are interconnected at the position of opening I, and the inlets of the air inlet pipe I and the air inlet pipe II are connected to the air supply device, and the outlet of the output pipe is connected to the upstream of the windowed experimental section; The cylinder is provided with n openings II below the horizontal symmetry plane. The particle supply mechanism includes a particle receiving chamber connected to the opening II and a driving mechanism for driving the cavity volume of the particle receiving chamber to decrease. When the cavity volume of the particle receiving chamber decreases, micron-sized particles contact the brush body from the opening II. n is greater than or equal to 2, and the micron-sized particles in the n particle receiving chambers are of different sizes and / or materials. The n driving mechanisms operate independently, simultaneously, or in a set sequence. The invention also includes a measurement component for measuring the gas-solid two-phase flow in the windowed experimental section.

2. The gas-solid two-phase velocity field synchronous measurement device according to claim 1, characterized in that: The opening I is arranged at one end of the cylinder away from the particle supply mechanism.

3. The gas-solid two-phase velocity field synchronous measurement device according to claim 1, characterized in that: The inlets of the air intake pipe I and the air intake pipe II are connected to each other and then connected to the air supply device.

4. The gas-solid two-phase velocity field synchronous measurement device according to claim 1, characterized in that: The driving mechanism comprises a linear driving mechanism and a bottom plate arranged on the output end of the linear driving mechanism, and the bottom plate and the opening II are arranged opposite to each other.

5. The gas-solid two-phase velocity field synchronous measurement device according to claim 1, characterized in that: The particle supply mechanism is provided with several groups along the arc direction of the cylinder; And / or, the particle supply mechanism is provided in a plurality of groups along the axial direction of the cylinder.

6. The gas-solid two-phase velocity field synchronous measurement device according to any one of claims 1 to 5, characterized in that: The high enthalpy supersonic airflow supply section includes a fuel storage tank, an air heater and a Laval nozzle which are arranged in sequence; The fuel tank is used to store liquid fuel carrying nano-scale particles; The air heater includes a mixing chamber and an air inlet connected to the mixing chamber, and the fuel storage tank is connected to the mixing chamber; The inlet of the Laval nozzle is connected to the mixing chamber, and the outlet is connected to the windowed test section.

7. The gas-solid two-phase velocity field synchronous measurement device according to claim 6, characterized in that: The mixing chamber is also connected with an oxygen inlet.

8. The gas-solid two-phase velocity field synchronous measurement device according to claim 6, characterized in that: The measurement component includes a synchronous controller, a pulse laser and a double-exposure CCD camera connected to the synchronous controller. The double-exposure CCD camera is set on both sides of the windowed experimental section, and the pulse laser is set on the upper and lower sides of the experimental section.

9. A method for synchronously measuring gas-solid two-phase velocity field, characterized in that: Using the gas-solid two-phase velocity field synchronous measurement device according to any one of claims 1 to 8 comprises the following steps: S1, a high-enthalpy supersonic airflow with nano-sized particles flows into the windowed experimental section, and the nano-sized particles act as airflow tracer particles and follow the airflow in the windowed experimental section; S2, the particle generator injects micron-sized particles upstream into the windowed experimental section; S3, the measurement component captures the scattered light of micron-sized particles and nano-sized particles, and separates the scattered light images of micron-sized particles and airflow tracer particles based on the particle image separation algorithm, and obtains the two-dimensional velocity field information of micron-sized particles and gas phase flow field at the same time through the cross-correlation algorithm or particle tracking algorithm.

10. The method for synchronously measuring gas-solid two-phase velocity field according to claim 9, wherein: In step S2, the particle generators work independently, simultaneously, or in a set order as needed to provide micron-sized particles with inconsistent sizes and / or inconsistent materials to the upstream of the windowed experimental section.

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