An apparatus and method for implementing hypersonic flow field transition trigger analysis

Abstract

The application provides a device and method for realizing hypersonic flow field transition inducement analysis, and belongs to the field of experimental fluid mechanics. The purpose is to analyze the transition change law in the transition test of a hypersonic wind tunnel. A thermocouple is arranged at the front end of a model, a high-speed infrared camera, a high-speed imaging camera and a high-repetition-frequency pulsed laser are arranged above the model; a beam expander is arranged at the front end of the high-repetition-frequency pulsed laser, and the laser beam emitted by the high-repetition-frequency pulsed laser is expanded into a conical body by the beam expander and covers the measured surface of the whole model; a narrow-band filter is arranged at the front end of the high-speed imaging camera, and the shooting field of view is consistent with that of the high-speed infrared camera; the thermocouple, the high-repetition-frequency pulsed laser, the high-speed infrared camera and the high-speed imaging camera are connected with a time sequence controller; and the thermocouple, the high-speed infrared camera and the high-speed imaging camera are connected with a computer. The application breaks through the limitation of insufficient transition change inducement analysis test means and provides support for in-depth research on the transition inducement law.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of experimental fluid mechanics, and particularly relates to a device and method for realizing transition inducement analysis of hypersonic flow field. BACKGROUND

[0002] Hypersonic wind tunnel test is the main means for carrying out related aerodynamic basic research and hypersonic vehicle engineering design. Its biggest advantage is that a large number of ground tests can be carried out at a relatively low cost to obtain relevant aerodynamic / thermal physical laws and provide basic measurement data for aerodynamic research and vehicle engineering design.

[0003] Transition phenomenon refers to the process of transition from laminar flow to turbulent flow after the hypersonic flow field passes through the model surface. The measurement of transition position, the research of transition process and the analysis of transition inducement law are of great significance for predicting and controlling the generation and development of transition, and based on the research foundation, the flight resistance of hypersonic vehicles can be optimized and the related performance can be improved.

[0004] At present, the test means for transition in the wind tunnel mainly concentrates on infrared temperature measurement technology to realize the visualization of transition position. There is a limitation of insufficient analysis test means for transition changes caused by aerodynamic heat / model surface topography changes, so that most of the tests are in the stage of "knowing the phenomenon but not knowing the reason", and the hypersonic wind tunnel lacks devices and methods for this problem, which restricts the further development of related tests.

[0005] In summary, it is urgent to design a device and method capable of analyzing the transition change law in hypersonic wind tunnel transition test, and breaking through the limitation of insufficient transition change inducement analysis test means. SUMMARY

[0006] In the following, a brief summary of the present application is given to provide a basic understanding of some aspects of the present application. It should be understood that this summary is not a comprehensive summary of the present application. It is not intended to determine the key or important parts of the present application, nor to limit the scope of the present application. Its purpose is only to give some concepts in a simplified form as a prelude to the more detailed description discussed later.

[0007] In view of this, in order to analyze the transition change law in hypersonic wind tunnel transition test, the present application provides a device and method for realizing transition inducement analysis of hypersonic flow field.

[0008] Scheme one: a device for realizing transition inducement analysis of hypersonic flow field, comprising a time sequence controller, a thermocouple, a model, a computer, a high-repetition-frequency pulsed laser, a high-speed infrared camera and a high-speed imaging camera.

[0009] The model front end is provided with a thermocouple, a high-speed infrared camera and a high-speed imaging camera are placed at the upper left of the model, and a high-repetition-rate pulsed laser is placed at the upper right;

[0010] The high-repetition-rate pulsed laser is provided with a beam expander at the front end, and the laser beam emitted by the high-repetition-rate pulsed laser is expanded by the beam expander to form a conical body covering the entire surface of the model to be measured;

[0011] The high-speed imaging camera is provided with a narrow-band filter at the front end, and the field of view is consistent with that of the high-speed infrared camera;

[0012] The thermocouple, high-repetition-rate pulsed laser, high-speed infrared camera and high-speed imaging camera are connected to the time sequence controller through BNC trigger lines; the thermocouple, high-speed infrared camera and high-speed imaging camera are connected to the computer through data transmission control lines.

[0013] Further, the frequency and instantaneous synchronicity of the thermocouple, high-repetition-rate pulsed laser, high-speed infrared camera and high-speed imaging camera are consistent.

[0014] Further, the center wavelength of the transmission spectrum of the narrow-band filter is the wavelength of the laser of the high-repetition-rate pulsed laser.

[0015] Scheme two, a method for realizing hypersonic flow field transition inducement analysis, which is realized by relying on the device for realizing hypersonic flow field transition inducement analysis in scheme one, specifically including the following steps:

[0016] S1. Install the high-repetition-rate pulsed laser, high-speed infrared camera and high-speed imaging camera on the wind tunnel chamber, ensure that the fields of view of the high-speed infrared camera and high-speed imaging camera are consistent, the field of view is the surface of the model to be measured, and the laser beam emitted by the high-repetition-rate pulsed laser can cover the surface of the model after expansion by the beam expander, and install a thermocouple in the internal laminar flow region of the model;

[0017] S2. Control the high-repetition-rate pulsed laser, high-speed infrared camera, high-speed imaging camera and thermocouple by using a computer, realize the synchronous work of the high-speed infrared camera, high-speed imaging camera, high-repetition-rate pulsed laser and thermocouple based on the time sequence controller, and ensure that the temperature collected by the thermocouple, the infrared image collected by the high-speed infrared camera and the model topography image collected by the high-speed imaging camera at the same time are stored in the computer;

[0018] S3. After the test starts, the time sequence controller receives the trigger signal of the wind tunnel to start working, and the synchronous data collected by the high-speed infrared camera, high-speed imaging camera and thermocouple are stored in the computer;

[0019] S4. Through data processing, the change curves of the transition position, the model temperature and the model surface relative roughness on the time axis are obtained, and the causes of the transition at different times are analyzed by comparing and analyzing the three curves.

[0020] The present application has the following beneficial effects relative to the prior art:

[0021] 1. The present application solves the problem of insufficient analysis of transition changes caused by aerodynamic heat, model surface morphology changes and other factors in existing hypersonic wind tunnel transition tests, and realizes the synchronous analysis of transition position, model surface morphology and model aerodynamic heat data on the time axis through synchronous data acquisition of high-speed imaging cameras, high-speed infrared cameras and thermocouples.

[0022] 2. The present application breaks through the limitations of insufficient experimental means for transition change cause analysis, and provides support for in-depth study of transition cause rules. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 It is a structural schematic diagram of a device for realizing hypersonic flow field transition cause analysis.

[0025] In the figure: 1 - time sequence controller, 2 - narrow-band filter, 3 - thermocouple, 4 - model, 5 - computer, 6 - high-repetition-rate pulsed laser, 7 - laser beam, 8 - beam expander, 9 - high-speed infrared camera, 10 - high-speed imaging camera. DETAILED DESCRIPTION

[0026] In order to make the technical solutions and advantages in the embodiments of the present application clearer and more apparent, the exemplary embodiments of the present application are further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not an exhaustive enumeration of all embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0027] Embodiment 1, refer to Figure 1 This embodiment is a device for realizing hypersonic flow field transition cause analysis, which comprises a time sequence controller 1, a thermocouple 3, a model 4, a computer 5, a high-repetition-rate pulsed laser 6, a high-speed infrared camera 9 and a high-speed imaging camera 10.

[0028] The model 4 is provided with a thermocouple 3 at the front end, and the high-speed infrared camera 9 and the high-speed imaging camera 10 are placed at the upper left of the model 4, and the high-repetition-rate pulsed laser 6 is placed at the upper right.

[0029] The high repetition rate pulsed laser 6 is provided with a beam expander 8, and the laser beam 7 emitted by the high repetition rate pulsed laser 6 is expanded by the beam expander 8 to form a cone that covers the entire surface of the model 4 to be measured;

[0030] The high-speed imaging camera 10 is provided with a narrow-band filter 2 at the front end, and the field of view is consistent with the high-speed infrared camera 9;

[0031] The thermocouple 3, the high repetition rate pulsed laser 6, the high-speed infrared camera 9 and the high-speed imaging camera 10 are connected to the time sequence controller 1 through the BNC trigger line; the thermocouple 3, the high-speed infrared camera 9 and the high-speed imaging camera 10 are connected to the computer 5 through the data transmission control line.

[0032] Further, the frequency and instantaneous synchronicity of the thermocouple 3, the high repetition rate pulsed laser 6, the high-speed infrared camera 9 and the high-speed imaging camera 10 are consistent.

[0033] Further, the center wavelength of the transmission spectrum of the narrow-band filter is the wavelength of the laser of the high repetition rate pulsed laser 6, which can ensure that the high-speed imaging camera 10 only collects the image of the surface topography change of the model 4 to be measured, and is not disturbed by other signals.

[0034] Embodiment 2, Reference Figure 1 This embodiment is a method for analyzing the transition inducement of hypersonic flow field, which is realized by relying on the device for analyzing the transition inducement of hypersonic flow field in embodiment 1, and specifically includes the following steps:

[0035] S1. Install the high repetition rate pulsed laser 6, the high-speed infrared camera 9 and the high-speed imaging camera 10 on the wind tunnel chamber, ensure that the fields of view of the high-speed infrared camera 9 and the high-speed imaging camera 10 are consistent, the field of view is the surface of the model 4 to be measured, and the laser beam 7 emitted by the high repetition rate pulsed laser 6 can cover the surface of the model 4 after being expanded by the beam expander 8; based on the time sequence of the surface topography image of the model 4 to be measured, the image is processed by the Canny edge detection algorithm, the total length of all recognized edge lines is calculated to obtain a quantitative index about the surface roughness, and a curve representing the change of the model roughness with time is established; install the thermocouple 3 in the front laminar flow area of the model 4; the thermocouple 3 can record the model temperature in real time, and the temperature change is mainly caused by the aerodynamic heating of the hypersonic flow field; based on the time sequence of the temperature recording data, a curve of the model 4 temperature changing with time can be obtained;

[0036] S2. Using the computer to control the high repetition rate pulsed laser 6, the high-speed infrared camera 9, the high-speed imaging camera 10 and the thermocouple 3, the time sequence controller 1 realizes the synchronous work of the high-speed infrared camera 9, the high-speed imaging camera 10, the high repetition rate pulsed laser 6 and the thermocouple 3, and ensures that the temperature collected by the thermocouple 3, the infrared image collected by the high-speed infrared camera 9 and the model 4 topography image collected by the high-speed imaging camera 10 at the same time are stored in the computer 5; the infrared image collected by the high-speed infrared camera 9 can be used to determine the transition position, because the heat transfer efficiency of laminar and turbulent airflow is different, there will be a very obvious temperature jump from low to high before and after the transition position, so the position of the maximum temperature gradient of the surface of the model 4 is the transition position; based on the time sequence of the infrared image, the curve of the transition position changing with time can be obtained;

[0037] S3. After the test starts, the time sequence controller 1 receives the trigger signal of the wind tunnel to start working, and the synchronous data collected by the high-speed infrared camera 9, the high-speed imaging camera 10 and the thermocouple 3 are stored in the computer 5;

[0038] S4. Through data processing, the curves of the transition position, the model 4 temperature and the model 4 surface relative roughness on the time axis are obtained, and the causes of the transition at different times are analyzed by comparing and analyzing the three curves.

[0039] Embodiment 3, reference Figure 1 This embodiment uses a device for realizing hypersonic flow field transition cause analysis in a hypersonic wind tunnel to perform a Mach 6.0 flow field transition measurement test, and studies whether the main cause of the transition of the surface of the aircraft model is the flow field aerodynamic heating or the model surface ablation topography change. Based on this requirement, the experiment is carried out, and the specific steps are as follows:

[0040] S1. Install the high repetition rate pulsed laser 6, the high-speed infrared camera 9 and the high-speed imaging camera 10 on the wind tunnel chamber, ensure that the fields of view of the high-speed infrared camera 9 and the high-speed imaging camera 10 are consistent, and the laser beam 7 emitted by the high repetition rate pulsed laser 6 can cover the surface of the model 4 after being expanded by the beam expander 8, and install the thermocouple 3 in the front laminar flow area inside the model 4; wherein the laser wavelength of the high repetition rate pulsed laser 6 is 532 nm, the filter installed on the high-speed imaging camera 10 is a 532±5 nm narrow band filter, and the high-speed imaging camera 10 only collects the diffuse reflection of the 532 nm laser on the surface of the model 4 when collecting the surface topography of the model 4;

[0041] S2. Using the computer to control the high repetition rate pulsed laser 6, the high speed infrared camera 9, the high speed imaging camera 10 and the thermocouple 3, the synchronous work of the high speed infrared camera 9, the high speed imaging camera 10, the high repetition rate pulsed laser 6 and the thermocouple 3 is realized based on the time sequence controller 1, the working acquisition frequency is 1 kHz, and it is ensured that the temperature collected by the thermocouple 3, the infrared image collected by the high speed infrared camera 9 and the model 4 topographic image collected by the high speed imaging camera 10 at the same time are stored in the computer 5;

[0042] S3. After the test starts, the time sequence controller 1 receives the trigger signal of the wind tunnel to start working, the test time is 30s, and the synchronous data collected by the high speed infrared camera 9, the high speed imaging camera 10 and the thermocouple 3 are stored in the computer 5;

[0043] S4. Through data processing, 30,000 groups of data of infrared images (transition position), model surface topographic images (ablation degree) and model temperature (aerodynamic heating condition) corresponding to the time axis are collected; after the test is completed, the above data is unfolded on the time axis and the change trend is observed, the influence weight of the ablation degree and the aerodynamic heating change on the transition position is analyzed, the cause of the transition is analyzed, and the transition law under the working condition is obtained.

[0044] The present application solves the problem of insufficient analysis of transition change caused by aerodynamic heating, model surface topographic change and other factors in the existing hypersonic wind tunnel transition test, and realizes the synchronous analysis of transition position, model surface topography and model aerodynamic heating data on the time axis through synchronous data collection of the high speed imaging camera, the high speed infrared camera and the thermocouple.

[0045] The present application breaks through the limitation of insufficient transition change cause analysis test means, and provides support for in-depth study of transition cause law.

[0046] Although the present application is described according to a limited number of embodiments, those skilled in the art, with the benefit of the above description, will appreciate that other embodiments can be conceived within the scope of the present application described herein. In addition, it should be noted that the language used in the specification is mainly selected for readability and teaching purposes, rather than for interpretation or limitation of the subject matter of the present application. Therefore, many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present application is illustrative rather than limiting, and the scope of the present application is defined by the appended claims.

Claims

1. An apparatus for implementing hypersonic flow field transition inception analysis, characterized by, It comprises a time sequence controller (1), a thermocouple (3), a model (4), a computer (5), a high repetition rate pulsed laser (6), a high-speed infrared camera (9) and a high-speed imaging camera (10). The model (4) is provided with the thermocouple (3) at the front end, and the high-speed infrared camera (9) and the high-speed imaging camera (10) are placed at the upper left of the model (4), and the high repetition rate pulsed laser (6) is placed at the upper right of the model (4). The high repetition rate pulsed laser (6) is provided with a beam expander (8) at the front end, and the laser beam (7) emitted by the high repetition rate pulsed laser (6) is expanded by the beam expander (8) to form a conical body covering the surface of the model (4) to be measured. The high-speed imaging camera (10) is provided with a narrow-band filter (2) at the front end, and the field of view is consistent with that of the high-speed infrared camera (9). The thermocouple (3), the high repetition rate pulsed laser (6), the high-speed infrared camera (9) and the high-speed imaging camera (10) are connected to the time sequence controller (1) through BNC trigger lines, and the thermocouple (3), the high-speed infrared camera (9) and the high-speed imaging camera (10) are connected to the computer (5) through data transmission control lines.

2. The apparatus for implementing hypersonic flow field transition trigger analysis according to claim 1, wherein, The frequency and instantaneous synchronism of the thermocouple (3), the high repetition rate pulsed laser (6), the high-speed infrared camera (9) and the high-speed imaging camera (10) are consistent.

3. The apparatus for implementing hypersonic flow field transition trigger analysis of claim 1, wherein, The transmission spectrum center wavelength of the narrow-band filter (2) is the laser wavelength of the high repetition rate pulsed laser (6).

4. A method for realizing hypersonic flow field transition inducement analysis, which is realized by the device for realizing hypersonic flow field transition inducement analysis according to claim 1, characterized in that, Specifically comprising the following steps: S1. Install the high repetition rate pulsed laser (6), the high-speed infrared camera (9) and the high-speed imaging camera (10) on the wind tunnel chamber, ensure that the fields of view of the high-speed infrared camera (9) and the high-speed imaging camera (10) are consistent, the field of view is the surface of the model (4) to be measured, and the laser beam (7) emitted by the high repetition rate pulsed laser (6) can cover the surface of the model (4) after being expanded by the beam expander (8), and install the thermocouple (3) in the front laminar flow area of the model (4); S2. Control the high repetition rate pulsed laser (6), the high-speed infrared camera (9), the high-speed imaging camera (10) and the thermocouple (3) by using the computer, realize the synchronous work of the high-speed infrared camera (9), the high-speed imaging camera (10), the high repetition rate pulsed laser (6) and the thermocouple (3) based on the time sequence controller (1), and ensure that the temperature collected by the thermocouple (3), the infrared image collected by the high-speed infrared camera (9) and the model (4) image collected by the high-speed imaging camera (10) at the same time are stored in the computer (5); S3. After the test starts, the time sequence controller (1) receives the trigger signal of the wind tunnel to start working, and the synchronous data collected by the high-speed infrared camera (9), the high-speed imaging camera (10) and the thermocouple (3) are stored in the computer (5); S4. Through data processing, the turning position on the time axis, the temperature of the model (4) and the variation curve of the surface relative roughness of the model (4) are obtained, and the causes of turning at different times are analyzed by comparing and analyzing the three curves.

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