阅读说明：本技术 一种平面激光诱导荧光方法流场测速标定系统 (Flow field speed measurement calibration system of planar laser induced fluorescence method ) 是由 戴殊韬 吴鸿春 苏毅聪 吴照斌 吴丽霞 翁文 林文雄 于 2020-12-22 设计创作，主要内容包括：本发明公开了一种平面激光诱导荧光方法流场测速标定系统,属于测速标定技术领域,能够解决现有流场测量系统中流场测速精度无法标定的问题。所述系统包括：第一激光器以及依次设置在第一激光器出射光路上的光学整形组件、反射件和透光屏；第一激光器用于输出激光束；光学整形组件用于将激光束整形成线状光束；反射件用于将线状光束反射至透光屏上；系统还包括图像采集装置、触发装置、转动装置和处理装置；反射件设置在转动装置上,转动装置用于带动反射件转动；触发装置用于触发图像采集装置,以使图像采集装置连续采集两张透光屏上的线性光束图像；处理装置用于根据两张线性光束图像,获得流场测量速度。本发明用于超高速流场测速精度的标定。(The invention discloses a flow field speed measurement calibration system based on a planar laser induced fluorescence method, belongs to the technical field of speed measurement calibration, and can solve the problem that the flow field speed measurement precision in the existing flow field measurement system cannot be calibrated. The system comprises: the device comprises a first laser, and an optical shaping component, a reflecting piece and a light-transmitting screen which are sequentially arranged on an emergent light path of the first laser; the first laser is used for outputting a laser beam; the optical shaping component is used for shaping the laser beam into a linear beam; the reflecting piece is used for reflecting the linear light beam to the light-transmitting screen; the system also comprises an image acquisition device, a triggering device, a rotating device and a processing device; the reflecting piece is arranged on the rotating device, and the rotating device is used for driving the reflecting piece to rotate; the triggering device is used for triggering the image acquisition device so as to enable the image acquisition device to continuously acquire linear light beam images on the two light-transmitting screens; and the processing device is used for obtaining the flow field measuring speed according to the two linear light beam images. The method is used for calibrating the speed measurement precision of the ultra-high-speed flow field.)

1. A flow field speed measurement calibration system of a planar laser induced fluorescence method is characterized by comprising the following steps: the device comprises a first laser, and an optical shaping component, a reflecting piece and a light-transmitting screen which are sequentially arranged on an emergent light path of the first laser;

the first laser is used for outputting a laser beam; the optical shaping component is used for shaping the laser beam into a linear beam; the reflecting piece is used for reflecting the linear light beams to the light-transmitting screen;

the system also comprises an image acquisition device, a triggering device, a rotating device and a processing device; the reflecting piece is arranged on the rotating device, and the rotating device is used for driving the reflecting piece to rotate; the triggering device is used for triggering the image acquisition device so that the image acquisition device continuously acquires linear light beam images on the two light-transmitting screens; and the processing device is used for obtaining the flow field measuring speed according to the two linear light beam images.

2. The system of claim 1, wherein the rotating device comprises a rotating table and a drive structure; the reflecting piece is arranged on the rotating table; the driving structure is connected with the center of the bottom surface of the rotating table and used for driving the rotating table to rotate so as to drive the reflecting piece to rotate.

3. The system of claim 2, wherein the triggering device comprises a second laser, a photodetector, and an aperture;

the diaphragm is arranged on the rotating table, and the second laser and the photoelectric detector are respectively positioned on the upper side and the lower side of the rotating table; the trigger laser output by the second laser can pass through the diaphragm and be received by the photoelectric detector;

the photoelectric detector is used for sending a trigger signal to the image acquisition device after receiving the trigger laser; and the image acquisition device is used for continuously acquiring two linear light beam images on the light-transmitting screen after delaying for a preset time after receiving the trigger signal.

4. The system of claim 3, wherein the second laser is a semiconductor laser.

5. The system of claim 3, wherein the image capture device is a high-speed camera.

6. The system according to claim 5, wherein the processing device is specifically configured to:

acquiring the distance between two linear beams in the two linear beam images;

and acquiring the ratio of the distance to the time interval between two shutters of the high-speed camera, and taking the ratio as the flow field measuring speed.

7. The system of claim 1, wherein the optical shaping component comprises a spherical lens and a cylindrical lens; the spherical lens is arranged on the light incident side of the cylindrical lens;

the spherical lens and the cylindrical lens are used for shaping the laser beam into a linear beam.

8. A system according to claim 1 or 2, wherein the reflecting member is a plane mirror.

9. The system of claim 1, wherein the first laser is a continuous laser.

10. The system of claim 3, wherein the signal received by the photodetector to trigger laser formation is a square wave signal.

Technical Field

The invention relates to a flow field speed measurement calibration system based on a planar laser induced fluorescence method, and belongs to the technical field of speed measurement calibration.

Background

The calibration of the ultra-high speed wind tunnel flow field speed measurement system is a world problem, and a stable ultra-high speed standard flow field cannot be obtained, so that the existing speed measurement for the ultra-high speed flow field is difficult and the precision cannot be determined; at present, no technical means for accurately and effectively calibrating the flow field velocity exists internationally.

Disclosure of Invention

The invention provides a flow field velocity measurement calibration system adopting a planar laser induced fluorescence method, which can solve the problem that the measurement precision of the flow field velocity in the existing flow field measurement system cannot be calibrated.

The invention provides a flow field velocity measurement calibration system of a planar laser induced fluorescence method, which comprises the following steps: the device comprises a first laser, and an optical shaping component, a reflecting piece and a light-transmitting screen which are sequentially arranged on an emergent light path of the first laser; the first laser is used for outputting a laser beam; the optical shaping component is used for shaping the laser beam into a linear beam; the reflecting piece is used for reflecting the linear light beams to the light-transmitting screen; the system also comprises an image acquisition device, a triggering device, a rotating device and a processing device; the reflecting piece is arranged on the rotating device, and the rotating device is used for driving the reflecting piece to rotate; the triggering device is used for triggering the image acquisition device so that the image acquisition device continuously acquires linear light beam images on the two light-transmitting screens; and the processing device is used for obtaining the flow field measuring speed according to the two linear light beam images.

Optionally, the rotating device includes a rotating table and a driving structure; the reflecting piece is arranged on the rotating table; the driving structure is connected with the center of the bottom surface of the rotating table and used for driving the rotating table to rotate so as to drive the reflecting piece to rotate.

Optionally, the triggering device includes a second laser, a photodetector and a diaphragm; the diaphragm is arranged on the rotating table, and the second laser and the photoelectric detector are respectively positioned on the upper side and the lower side of the rotating table; the trigger laser output by the second laser can pass through the diaphragm and be received by the photoelectric detector; the photoelectric detector is used for sending a trigger signal to the image acquisition device after receiving the trigger laser; and the image acquisition device is used for continuously acquiring two linear light beam images on the light-transmitting screen after delaying for a preset time after receiving the trigger signal.

Optionally, the second laser is a semiconductor laser.

Optionally, the image capturing device is a high-speed camera.

Optionally, the processing device is specifically configured to: acquiring the distance between two linear beams in the two linear beam images; and acquiring the ratio of the distance to the time interval between two shutters of the high-speed camera, and taking the ratio as the flow field measuring speed.

Optionally, the optical shaping assembly includes a spherical lens and a cylindrical lens; the spherical lens is arranged on the light incident side of the cylindrical lens; the spherical lens and the cylindrical lens are used for shaping the laser beam into a linear beam.

Optionally, the reflecting member is a plane mirror.

Optionally, the first laser is a continuous laser.

Optionally, the signal formed by receiving the trigger laser by the photodetector is a square wave signal.

The invention can produce the beneficial effects that:

the flow field speed measurement calibration system adopting the planar laser induced fluorescence method provided by the invention has the advantages that the high-speed rotating mirror method is adopted, and the mobile laser stripes with the speed capable of being calibrated are introduced to replace the planar laser induced fluorescence stripes generated in the wind tunnel flow field in the prior art, so that the flow field measurement speed is calibrated. The calibration system has repeatability and standard, and each parameter can be traced and can be used as the standard of the speed measurement range and the measurement precision in the flow field measurement.

Drawings

FIG. 1 is a schematic structural diagram of a flow field velocity measurement calibration system of a planar laser-induced fluorescence method according to an embodiment of the present invention;

fig. 2 is a schematic view of a linear light beam image acquired by the image acquisition module according to the embodiment of the present invention;

fig. 3 is a schematic diagram of signals output by a photodetector according to an embodiment of the present invention.

List of parts and reference numerals:

11. a first laser; 12. a reflector; 13. a light-transmitting screen; 14. an image acquisition device; 15. a rotating table; 16. a drive structure; 17. a second laser; 18. a photodetector; 19. a diaphragm; 20. a spherical lens; 21. a cylindrical lens; 22. a linear beam image; 23. a square wave signal.

Detailed Description

The present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

The embodiment of the invention provides a flow field velocity measurement calibration system by a planar laser-induced fluorescence method, as shown in fig. 1 to 3, the system comprises: the device comprises a first laser 11, and an optical shaping component, a reflecting part 12 and a light-transmitting screen 13 which are sequentially arranged on an emergent light path of the first laser 11; a first laser 11 for outputting a laser beam; the optical shaping component is used for shaping the laser beam into a linear beam; the reflecting member 12 is used for reflecting the linear light beam to the light-transmitting screen 13; the system also comprises an image acquisition device 14, a triggering device, a rotating device and a processing device; the reflecting piece 12 is arranged on a rotating device, and the rotating device is used for driving the reflecting piece 12 to rotate; the triggering device is used for triggering the image acquisition device 14 so that the image acquisition device 14 continuously acquires the linear light beam images 22 on the two light-transmitting screens 13; the processing device is used for obtaining the flow field measuring speed according to the two linear light beam images 22.

Wherein, the image capturing device 14 may be a high-speed camera; the reflector 12 is a plane mirror; the first laser 11 is a continuous laser.

Referring to fig. 1, the optical shaping assembly may include a spherical lens 20 and a cylindrical lens 21; the spherical lens 20 is arranged on the light incident side of the cylindrical lens 21; the spherical lens 20 and the cylindrical lens 21 are used to shape the laser beam into a linear beam.

The processing device is specifically configured to: acquiring the distance between two linear beams in the two linear beam images 22; and acquiring the ratio of the distance to the time interval between two shutters of the high-speed camera, and taking the ratio as the flow field measurement speed.

The invention adopts a high-speed rotating mirror method and introduces the moving laser stripe with the speed capable of being calibrated to replace the plane laser induced fluorescence stripe generated in the wind tunnel flow field in the prior art so as to calibrate the flow field measuring speed. The calibration system has repeatability and standard, and each parameter can be traced and can be used as the standard of the speed measurement range and the measurement precision in the flow field measurement.

In the present embodiment, the rotating means comprises a rotating table 15 and a driving structure 16; the reflecting member 12 is provided on the rotating table 15; the driving structure 16 is connected with the center of the bottom surface of the rotating table 15, and the driving structure 16 is used for driving the rotating table 15 to rotate so as to drive the reflecting member 12 to rotate.

Further, the triggering device includes a second laser 17, a photodetector 18 and a diaphragm 19; the diaphragm 19 is arranged on the rotating table 15, and the second laser 17 and the photoelectric detector 18 are respectively positioned on the upper side and the lower side of the rotating table 15; the trigger laser output by the second laser 17 can pass through the diaphragm 19 and be received by the photoelectric detector 18; the photodetector 18 is used for sending a trigger signal to the image acquisition device 14 after receiving the trigger laser; the image acquisition device 14 is configured to continuously acquire the linear light beam images 22 on the two transparent screens 13 after delaying for a preset time after receiving the trigger signal.

Wherein the second laser 17 is a semiconductor laser; the photodetector 18 may be a photosensor. The signal that triggers the formation of laser light is received by the photodetector 18 as a square wave signal 23.

Specifically, referring to fig. 1 to 3, the continuous laser output by the continuous laser device passes through the spherical lens 20, the cylindrical lens 21, and the reflector, and is focused on the transparent screen 13 to form a linear stripe; focusing the high-speed camera on the transparent screen 13 to shoot a stripe image; the rotary table 15 is provided with a diaphragm 19, laser output by the semiconductor laser can be received by the photoelectric sensor if the laser penetrates through the diaphragm 19, and output signals can be used as marks of linear stripe positions for triggering a shutter of the high-speed camera.

During operation, the driving structure 16 drives the rotating table 15 to rotate at a high speed, and the linear stripes move on the transparent screen 13 at a high speed. The diaphragm 19 also rotates at a high speed along with the rotating table 15, and the photoelectric sensor receives laser emitted by the semiconductor laser through the diaphragm 19 to generate a square wave signal 23 for triggering the high-speed camera. The high-speed camera delays for a certain time, starts a camera shutter after the stripes are transferred into a camera field of view, and continuously shoots two stripe images. The distance between two stripes is obtained through image processing, and the distance is divided by the time interval between two shutters of the camera to obtain the measuring speed. Therefore, the method can be used for calibrating the precision of the speed measurement value of the plane laser induced fluorescence method speed measurement of the high-speed flow field.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.