CN111337220A - High-speed flight test flow field measurement system - Google Patents

Abstract

The invention relates to a flow field measurement system for a high-speed flight test, comprising a head cabin, a wire, a rear cabin, a recorder assembly, a camera box assembly and a video collector; the head cabin is a research cabin for a high-speed flight test, and the wire adopts One end of the planting method or bonding method is fixed on the area of interest in the head cabin, the rear cabin is used to place and fix stand-alone equipment and is connected with the front cabin through axial screws, and the camera box assembly is fixed through the wall on the rear bulkhead surface for photographing the silk thread area. Flow field distribution, video collector and recorder components are fixed inside the rear cabin, respectively used for data collection and storage of the flow field images in the silk thread area.

Description

A high-speed flight test flow field measurement system

technical field

The invention relates to a high-speed flight test flow field measurement system, which belongs to the field of aerodynamics research.

Background technique

Numerical calculation, wind tunnel test and flight test are three methods of aerodynamic research. Among them, the flight test can obtain a large amount of actual flight data at a lower test cost to determine the availability and accuracy of the relevant theory, and to promote the further development of the theory. In the process of flight test, the change law of the flow field on the surface of the aircraft is a very important research content.

The high-speed flight mentioned in this paper specifically refers to the flight whose flight speed is not less than 5 times the speed of sound. Most of the existing high-speed flight test flow field measurement methods are to arrange a large number of temperature or pressure sensors on the wall of the aircraft structure. The sensor data is recorded and analyzed to obtain the change rule of the flow field. In this case, a large number of sensor interfaces need to be processed for the structural shell of the aircraft, and the production is difficult; due to the large number of sensors, the product assembly is difficult; limited by the arrangement of the sensors, the flow field display is often not intuitive, and the data analysis is more difficult. Large; the flow field distribution cannot be obtained for small size models and curved thin airfoil surfaces.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is to propose a high-speed flight test flow field measurement system, which can simultaneously meet the requirements of simple production and assembly, intuitive measurement results, strong model size adaptability, and simple and reliable measurement scheme.

The technical solution of the present invention is: a high-speed flight test flow field measurement system, including a head cabin, a wire, a rear cabin, a recorder assembly, a camera box assembly, and a video collector; the head cabin is for research purposes in high-speed flight tests In the cabin section, one end of the silk thread is fixed to the concerned area of the head cabin by planting method or bonding method. The rear cabin is used to place and fix stand-alone equipment and is connected with the front cabin through axial screws. The camera box assembly is fixed on the rear cabin wall through the wall. It is used to photograph the flow field distribution in the silk thread area. The video collector and the recorder are fixed inside the rear cabin, and are respectively used for data collection and storage of the captured silk thread area flow field images.

Preferably, the camera case assembly includes glass, a camera case body, a camera case cover, a camera protective case, a camera, a cable sealing cover, a high temperature resistant buffer pad A, a high temperature resistant buffer pad B, a limit piece; a high temperature resistant buffer pad A and high temperature resistant buffer pads B are distributed on both sides of the glass. The three are limited by the limit piece and fixed on the main body of the camera case. After the camera and the protective case of the camera are fixed in place, they are installed on the cover of the camera case as a whole. The cover is connected to the main body of the camera box. After the camera cable is connected in place, the cable sealing cover is installed on the tail of the main body of the camera box, and the cable is fixed and sealed by applying glue at the gap.

Preferably, a square hole is formed on the main body of the camera box, the cross section of the glass is convex, the high temperature resistant buffer pad A is a closed square frame structure, and is sleeved on the convex shape, and the upper part of the convex structure is connected to the The square holes are matched; the high temperature resistant buffer pad B is a U-shaped frame, placed on the lower surface of the convex shape, and the limiting piece is a U-shaped structure, which is installed on the camera box body close to the high temperature resistant buffer pad B.

Preferably, a gap of 0.5 mm is reserved around the glass and the inner wall of the main body of the camera box, and the gap is filled with high-temperature sealant.

Preferably, the camera box assembly is conformal to the outer surface of the rear cabin and the outer surfaces of the two are flush, there is no reverse airflow step around the camera box assembly, and the downstream airflow step is not greater than 0.5mm.

Preferably, the incident direction of the light in the wire area is not perpendicular to the glass plane.

确定满足使用要求的焦距范围，进而确定相机镜头规格。Preferably, the same camera is matched with lenses of various specifications, according to the formula

Determine the focal length range that meets the usage requirements, and then determine the camera lens specifications.

Preferably, the glass is made of quartz glass, the temperature resistance is not lower than 1000°C, the upper and lower sides of the glass are coated with a hydrophobic film, the length and width of the glass are not more than 150mm, and the thickness is not less than 10mm.

Preferably, the diameter of the wire is 0.1-1 mm, the length of the wire exposed on the surface of the model is 10-80 mm, and the distance between the wire holes is 10-80 mm.

Preferably, the half cone angle of the rear cabin is not less than 25°, and the half cone angle of the rear cabin should be greater than the half cone angle of the head cabin and the difference between the two is not less than 20°.

Preferably, the recorder assembly includes a conformal clamp, a recorder, and a connecting plate; the connecting plate is fixed on the inner wall of the rear cabin, the recorder is placed on the connecting plate, and the conformal clamp and the connecting plate are connected in place to record the The instrument is securely fixed between the two.

Preferably, the recorder has a dual redundant data backup function, and the single-unit shape includes a spherical surface and a cylindrical surface, which can effectively avoid stress concentration, and is fixed on the connecting plate by a conformal clamp, which can adapt to the working environment such as landing impact.

The beneficial effects of the present invention compared with the prior art are:

A flow field measurement system for high-speed flight test is proposed, which can meet the requirements of simple production and assembly, intuitive measurement results, strong model size adaptability, and simple and reliable measurement scheme.

The high-speed flight test flow field measurement system can obtain a small size model and the flow field distribution of a curved thin airfoil .

The high-speed flight test flow field measurement system is simple in composition, and the overall shape of the aircraft will not be damaged after the introduction of the system, so as to avoid bringing new problems to other systems. The system has multiple heat sealing capabilities for high safety.

The high-speed flight test flow field measurement system has strong adaptability and wide working range. The high-speed flight test flow field measurement system can work stably and reliably under normal temperature and high temperature conditions not exceeding 500 °C. The high-speed flight test flow field measurement system can work stably and reliably under the vibration, shock and overload environments of various typical rocket operating conditions.

The camera, glass, buffer pad, etc. for the flow field measurement of the high-speed flight test are all integrated into the camera box assembly, and the assembly is simple and reliable.

Description of drawings

FIG. 1 is a schematic diagram of the composition of a flow field measurement system for a high-speed flight test of the present invention.

Figure 2 is a schematic diagram of the components of the recorder.

FIG. 3 is a schematic diagram of the composition of the camera box assembly of the present invention.

FIG. 4 is an exploded view of the components of the camera box assembly of the present invention.

FIG. 5 is a schematic diagram of the refraction of light after passing through the transparent glass.

In Figure 1: 1 head cabin, 2 silk cables, 3 rear cabins, 4 recorder components, 5 camera box components, 6 video collectors.

In Figure 2: 41 conformal clamp, 42 recorder, 43 connecting plate.

In Figure 3 and Figure 4: 51 glass, 52 camera case body, 53 camera case cover, 54 camera protective case, 55 camera, 56 cable sealing cover, 57 high temperature buffer pad A, 58 high temperature buffer pad B, 59 limit bit slice.

Detailed ways

The present invention will be further elaborated below in conjunction with the examples.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings 1-5 in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

1, the present invention provides a technical solution: a high-speed flight test flow field measurement system, comprising a head cabin 1, a wire 2, a rear cabin 3, a recorder assembly 4, a camera box assembly 5, and a video collector 6, The head cabin is a research cabin for high-speed flight tests. The wire is fixed to the area of interest in the head cabin by bonding. The rear cabin is used to place and fix stand-alone equipment and is connected with the front cabin through axial screws. The recorder components and video The collector is fixed inside the rear cabin, and the camera box assembly is fixed on the wall surface of the rear cabin through the wall.

During the flight, the silk thread bonded to the head cabin can display the flow field distribution in the area in real time. The camera shoots the flow field display in the silk thread area, and the video collector collects and stores the data of the image captured by the camera in the In the recorder, after the flight test is completed, the required image data is obtained by recovering the recorder, and then the variation law of the flow field in the silk thread area during the flight is obtained.

As shown in FIG. 2, the recorder assembly included in the present invention includes a conformal clamp 41, a recorder 42, and a connecting plate 43. The connecting plate is fixed on the inner wall of the rear cabin, the recorder is placed on the connecting plate, and the conformal clamp After the hoop and the connecting plate are connected in place, the recorder can be securely fixed between the two. The recorder has the function of dual redundant data backup design. The shape of the single machine is mainly spherical and cylindrical, which can effectively avoid stress concentration. It is fixed on the connecting plate by the conformal clamp, which can adapt to the working environment such as landing impact.

As shown in FIG. 3 , the camera case assembly included in the present invention includes a glass 51 , a camera case body 52 , a camera case cover 53 , a camera protective case 54 , a camera 55 , a cable sealing cover 56 , a high temperature resistant buffer pad A57 , The high temperature buffer pad B58, the limit sheet 59, the high temperature resistant buffer pad A and the high temperature resistant buffer pad B are distributed on both sides of the glass, and the three are limited by the limit sheet and fixed on the main body of the camera case, the camera and the camera protective shell After being fixed in place, it is installed on the camera case cover as a whole. The camera case cover and the camera case body are connected by bolts. After the camera cable is connected in place, the cable sealing cover is installed at the end of the camera case body by applying glue at the gap. Cable fixing and sealing.

The camera box assembly needs to be installed through the wall. Based on thermal protection considerations, it should be kept flush with the outer surface of the rear cabin. There is no reverse airflow step around the camera box assembly, and the downstream airflow step is not greater than 0.5mm.

将玻璃折射率及具体工况的入射角代入，可求得光线偏移距离。The incident direction of the light in the silk line area is not perpendicular to the glass plane. When arranging the camera position, it is necessary to calculate the refraction of the optical path to obtain the offset distance of the light after refraction by the glass. In Figure 5, i is the incident angle, r is the exit angle, n is the refractive index, and the glass thickness is a, n=sin i/sinr, r=arcsin(sin i/n), the polarization of the light after being refracted by the glass can be obtained. move distance

By substituting the refractive index of the glass and the incident angle of the specific working conditions, the light offset distance can be obtained.

可确定满足使用要求的焦距范围，进而确定相机镜头规格。The same camera can be matched with lenses of various specifications, according to the formula

The focal length range that meets the usage requirements can be determined, and then the camera lens specifications can be determined.

When the flow field measurement system is working, it should be ensured that the wire area of the test vehicle is well lit.

High temperature resistant buffers are arranged on both sides of the glass, and a 0.5mm gap is reserved around the glass and the inner wall of the camera box. The gap is filled with high temperature sealant. The above measures can improve the adaptability of the glass to vibration and shock environments. The high temperature resistant buffer pad A and the high temperature resistant buffer pad B used can withstand temperatures above 500°C without deterioration or decomposition.

A vibration damping pad is arranged at the connection between the mechanical interface of the camera box body and the rear compartment, and a 0.5mm gap is designed between the side wall of the camera box body and the opening of the rear compartment. And improve the adaptability of products to vibration and shock environments.

The cable sealing cover at the rear of the camera box body is mainly used to seal the camera cable. There is a gap between the cable and the opening of the sealing cover. The gap is filled with high-temperature sealant. When the hot air enters the inside of the box, it will not further enter the inside of the rear compartment, which improves the reliability of the thermal sealing of the camera box assembly.

The light-transmitting glass is made of quartz glass, the temperature resistance is not lower than 1000 ° C, it has a very low thermal expansion coefficient, high heat resistance, excellent chemical stability, excellent electrical insulation, low and stable ultrasonic delay performance, the most It has excellent UV-transmitting spectral performance, visible light and near-infrared spectral performance, and has mechanical properties higher than ordinary glass. The upper and lower sides of the glass are coated with a hydrophobic film. The length and width of the glass shall not exceed 150mm, and the thickness shall not be less than 10mm.

The silk thread can be fixed by the planting method or the bonding method, which is determined according to the actual working conditions. The selected silk thread is soft and lightweight, and can withstand temperatures above 500K without deterioration. The diameter of the silk thread is 0.1-1 mm, the length of the silk thread exposing the surface of the model is 10-80 mm, and the distance between the thread holes is 10-80 mm.

The half cone angle of the rear cabin should not be less than 25°, and the half cone angle of the rear cabin should be greater than the half cone angle of the head cabin, and the difference between the two should not be less than 20°, so as to avoid the lack of vision and the unrecognizable image.

To sum up, in a preferred embodiment, the silk thread is a quartz fiber thread, which is soft and lightweight, and can withstand a temperature of 1000°C without deterioration. The diameter of the wire is 0.8mm, the length of the wire exposed on the surface of the model is 40mm, and the distance between the wire holes is 40mm. The camera box assembly is conformal to the outer surface of the rear cabin, and there are no steps around it. The half cone angle of the rear cabin is 25°, and the half cone angle of the head cabin is 5°. The selected high temperature buffer pad A and high temperature buffer pad B are customized with Dq441J-108 high temperature glue, and the high temperature sealant applied to each gap of the camera components is Dq441J-108 high temperature glue, which can withstand the temperature of 500 ℃ without deterioration. The light-transmitting glass is made of quartz glass, the grade is JGS1, the temperature resistance is 1200°C, the length and width of the glass are 130mm, and the thickness is 15mm. The incident angle of the incident light of the measuring system is about 70°, the refractive index of the glass is 1.7, the light deviation is about 10.7mm, and the camera position is adjusted accordingly.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (12)

1. a high-speed flight test flow field measurement system, is characterized in that: comprise head cabin, silk thread, rear cabin, recorder assembly, camera box assembly, video collector; Described head cabin is the research cabin section of high-speed flight test , One end of the silk thread is fixed to the area of interest in the head cabin by planting method or bonding method. The rear cabin is used to place and fix stand-alone equipment and is connected with the front cabin by axial screws. The camera box assembly is fixed on the rear cabin wall through the wall. To shoot the flow field distribution in the silk thread area, the video collector and the recorder are fixed inside the rear cabin, and are used for data collection and storage of the captured silk thread area flow field images respectively. 2. The system according to claim 1, wherein the camera case assembly comprises glass, a camera case body, a camera case cover, a camera protective case, a camera, a cable sealing cover, a high temperature resistant cushion A, a high temperature resistant cushion Buffer pad B, limit sheet; high temperature resistant buffer pad A and high temperature resistant buffer pad B are distributed on both sides of the glass, the three are limited by the limit sheet and fixed on the main body of the camera box, the camera and the camera protective shell are fixed in place Then, it is installed on the camera case cover as a whole. The camera case cover is connected to the camera case body. After the camera cable is connected in place, the cable sealing cover is installed at the end of the camera case body. seal. 3. The system according to claim 2, wherein a square hole is formed on the main body of the camera box, the cross section of the glass is convex, and the high temperature resistant buffer pad A is a closed square frame structure, which is sleeved on the On the convex shape, the upper part of the convex structure matches the square hole; the high temperature resistant buffer pad B is a U-shaped frame, which is placed on the lower surface of the convex shape, and the limit piece is a U-shaped structure, which is close to the high temperature resistant buffer Pad B is attached to the camera case body. 4 . The system according to claim 3 , wherein a gap of 0.5 mm is reserved around the glass and the inner wall of the camera box body, and the gap is filled with high-temperature sealant. 5 . 5 . The system according to claim 1 , wherein the camera box assembly is conformal to the outer surface of the rear cabin and the outer surfaces of the two are flush, there is no reverse airflow step around the camera box assembly, and the downstream airflow step is not greater than 0.5mm. 6. The system according to claim 2, wherein the incident direction of the light in the wire area is not perpendicular to the glass plane. 7. The system according to claim 2, wherein: the same camera is matched with lenses of various specifications, according to the formula

Determine the focal length range that meets the usage requirements, and then determine the camera lens specifications. 8. The system according to claim 2, characterized in that: the glass is selected from quartz glass, the temperature resistance is not lower than 1000 ℃, the upper and lower sides of the glass are coated with a hydrophobic film, and the length and width of the glass are not more than 150mm, The thickness is not less than 10mm. 9 . The system according to claim 1 , wherein the diameter of the wire is 0.1-1 mm, the length of the wire exposed on the surface of the model is 10-80 mm, and the distance between the wire holes is 10-80 mm. 10 . 10. The system according to claim 1, wherein the half cone angle of the rear cabin is not less than 25°, the half cone angle of the rear cabin should be greater than the half cone angle of the head cabin and the difference between the two is not less than 20°. 11. The system according to claim 1, wherein: the recorder assembly comprises a conformal clamp, a recorder, and a connecting plate; the connecting plate is fixed on the inner wall of the rear cabin, and the recorder is placed on the connecting plate, After the conformal clamp and the connecting plate are connected in place, the recorder is reliably fixed between them. 12 . The system according to claim 11 , wherein the recorder has a dual redundant data backup function, and the single-machine shape includes a spherical surface and a cylindrical surface. 13 .

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