Tracer particle release device of wind tunnel laser Doppler velocimeter and test method

Abstract

The invention discloses a tracer particle release device of a wind tunnel laser Doppler velocimeter and a test method. The device comprises a wind tunnel, a support, a pure water smoke generator, a smoke guide rod and a laser Doppler velocimeter. The support is fixed in a wind tunnel and used for fixing a test piece. The pure water smoke generator is used for generating pure water smoke with tracer particles; one end part of the smoke guide rod is connected with the pure water smoke generator, and the other end part of the smoke guide rod is provided with a smoke nozzle which faces the downstream in the longitudinal direction of the wind tunnel and is positioned on the upstream of the test piece; the relative position between the smoke nozzle and the test piece is adjustable in the transverse direction and the longitudinal direction of the wind tunnel; the laser multispectral rib velocimeter is used for measuring a flow field around the test piece. According to the invention, laser Doppler velocimeter flow field measurement can be carried out in a large-size nozzle wind tunnel environment, the number of effective measurement particles of particle cloud and mist in a measured space area and the stability of a flow field can be improved to the maximum extent, and stable measurement of a laser Doppler velocimeter is realized.

Description

Technical Field

[0001] The invention relates to the technical field of wind tunnel testing, and in particular to a wind tunnel laser Doppler velocimeter tracer particle release device and a testing method. Background Art

[0002] Laser Doppler velocimeter is a non-contact, high-precision flow field velocity measurement device, usually used in conjunction with a wind tunnel. It is used to measure single-point flow velocity, flow direction, turbulence, or to measure the flow field distribution in a set area. The existing laser Doppler velocimeter measurement distance (the measurement distance can be understood as the distance between the probe and the test piece) is 0.1 to 1.5 meters, and the particle cloud released by the particle release device used in conjunction with the laser Doppler velocimeter is difficult to diffuse quickly. At the same time, the flow of particle clouds in a large space will destroy the flow field being tested and increase the turbulence of the process being tested. Therefore, the existing laser Doppler velocimeter tracer particle release device is mostly suitable for small wind tunnels or small-scale experimental devices, and cannot be used for flow field measurements for large nozzles and full-size wind tunnel tests. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide a wind tunnel laser Doppler velocimeter tracer particle release device, which can realize the laser Doppler velocimeter flow field measurement in a large-size nozzle wind tunnel environment, and can maximize the effective measurement particle number of the particle cloud in the measured space area and the flow field stability, so as to realize the stable measurement of the laser Doppler velocimeter.

[0004] The wind tunnel laser Doppler velocimeter tracer particle release device according to the first embodiment of the present invention comprises:

[0005] Wind tunnel;

[0006] A bracket, wherein the bracket is fixed in the wind tunnel and is used to fix the test piece;

[0007] A pure water smoke generator, wherein the pure water smoke generator is used to generate pure water smoke with tracer particles;

[0008] A smoke guide rod, one end of which is connected to the pure water smoke generator, and the other end of which is provided with a smoke nozzle, which faces downstream in the longitudinal direction of the wind tunnel and is located upstream of the test piece; the relative position between the smoke nozzle and the test piece is adjustable in the transverse and longitudinal directions of the wind tunnel;

[0009] Laser Doppler velocimeter, the laser multispectral rib velocimeter is used to measure the flow field around the test piece.

[0010] According to the wind tunnel laser Doppler velocimeter tracer particle release device of the first aspect of the present invention, laser Doppler velocimeter flow field measurement is carried out in a large-size nozzle wind tunnel environment, and the relative position between the smoke nozzle and the specimen can be adjusted in the transverse and longitudinal directions of the wind tunnel; in this way, the test section can be determined by adjusting the transverse distance of the specimen relative to the smoke nozzle, and different test sections can be determined by adjusting different transverse distances of the specimen relative to the smoke nozzle; and by adjusting the longitudinal distance of the smoke nozzle relative to the specimen, the maximum tracer particle concentration and the best flow field stability can be achieved; the velocity of the pure water smoke ejected from the smoke nozzle can be adjusted by changing the injection flow rate of the pure water smoke, and the turbulence of the flow in the measured space area, i.e., the space around the specimen, can be reduced by the smoke guide rod, so as to maximize the number of tracer particles effectively measured by the pure water smoke in the measured space area and the flow field stability, and achieve stable measurement of the laser Doppler velocimeter.

[0011] In some embodiments, the bracket includes a support frame and a specimen fixing rod, the support frame is fixed to the wind tunnel, the specimen fixing rod extends laterally along the wind tunnel and is fixed to the support frame, and one end of the specimen fixing rod is used to fix the specimen.

[0012] In some embodiments, a specimen clamp is provided at one end of the specimen fixing rod, and the specimen clamp is used to clamp the specimen.

[0013] In some embodiments, the specimen fixing rod is movably fixed on the support frame in the transverse direction of the wind tunnel, or the specimen fixing rod is a telescopic rod.

[0014] In some embodiments, the smoke guide rod is fixed to the support frame.

[0015] In some embodiments, a smoke inlet is provided at one end of the smoke guide rod, and the smoke inlet is connected to the pure water smoke generating device.

[0016] In some embodiments, the smoke guide rod is L-shaped.

[0017] In some embodiments, the smoke guide rod is movably fixed on the support frame in the longitudinal direction of the wind tunnel.

[0018] The second aspect of the present invention also provides a test method for a wind tunnel laser Doppler velocimeter tracer particle release device.

[0019] According to the second aspect of the present invention, a method for testing a wind tunnel laser Doppler velocimeter tracer particle release device is performed using the wind tunnel laser Doppler velocimeter tracer particle release device according to the first aspect of the present invention, comprising the following steps:

[0020] Fixing the test piece on the bracket;

[0021] Then, the pure water smoke generator and the laser Doppler velocimeter are turned on, and the distance between the test piece and the smoke nozzle in the horizontal direction of the wind tunnel is adjusted to determine the test section;

[0022] The wind tunnel inflow is then opened, the distance of the smoke nozzle relative to the test piece in the longitudinal direction of the wind tunnel is adjusted, and the reading of the laser Doppler velocimeter is observed.

[0023] According to the testing method of the wind tunnel laser Doppler velocimeter tracer particle releasing device according to the second aspect of the present invention, since the wind tunnel laser Doppler velocimeter tracer particle releasing device of the first aspect of the present invention is used for testing, the testing method of the wind tunnel laser Doppler velocimeter tracer particle releasing device according to the second aspect of the present invention has the same technical effect as the wind tunnel laser Doppler velocimeter tracer particle releasing device of the first aspect of the present invention, which will not be repeated here.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 is a front view of a partial structure of a tracer particle release device for a wind tunnel laser Doppler velocimeter according to an embodiment of the first aspect of the present invention;

[0027] Figure 2 yes Figure 1 Left view of

[0028] Figure 3 yes Figure 1 Top view of the .

[0029] Reference numerals

[0030] Bracket 1; support frame 101; chassis 1011; upright pole 1012; specimen fixing pole 102; specimen fixture 103;

[0031] Smoke guide rod 2; smoke inlet 201; smoke nozzle 202. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] The first aspect of the present invention provides a wind tunnel laser Doppler velocimeter tracer particle release device.

[0034] like Figures 1 to 3 As shown, the wind tunnel laser Doppler velocimeter tracer particle release device according to the first aspect of the present invention includes a wind tunnel (not shown in the figure), a bracket 1, a pure water smoke generator (not shown in the figure), a smoke guide rod 2 and a laser Doppler velocimeter (not shown in the figure).

[0035] Among them, the wind tunnel is used for wind to flow longitudinally along the wind tunnel, and can be a large-sized nozzle wind tunnel.

[0036] The bracket 1 is fixed in the wind tunnel. The bracket 1 is used to fix the test piece, so that the test piece will not be blown away by the wind in the wind tunnel and will not move in the wind.

[0037] The pure water smoke generator is used to generate pure water smoke with tracer particles. The pure water smoke flow rate sprayed by the pure water smoke generator can be spray flow rate>2L / s, and the water content in the pure water smoke is <10g / L.

[0038] One end of the smoke guide rod 2 is connected to the pure water smoke generator, and the other end of the smoke guide rod 2 is provided with a smoke nozzle 202, that is, the pure water smoke generated by the pure water smoke generator enters the smoke guide rod 2 from one end of the smoke guide rod 2, and is ejected from the smoke nozzle 202 of the smoke guide rod 2, and the smoke guide rod 2 plays a role in transmitting smoke; the smoke nozzle 202 is oriented downstream in the longitudinal direction of the wind tunnel, that is, the direction of the smoke nozzle is in the downwind direction, and is located upstream of the specimen; the relative position between the smoke nozzle 202 and the specimen is adjustable in the transverse and longitudinal directions of the wind tunnel; in this way, the test section can be determined by adjusting the transverse distance of the specimen relative to the smoke nozzle 202, and different test sections can be determined by adjusting different transverse distances of the specimen relative to the smoke nozzle 202, so as to realize the flow field measurement of different test section positions of the specimen; and by adjusting the longitudinal distance of the smoke nozzle 202 relative to the specimen, the optimal flow field stability and tracer particle concentration around the specimen are realized.

[0039] Laser multispectral rib velocimeter is used to measure the flow field around the specimen.

[0040] During the test, the specimen is fixed on the bracket 1; then the pure water smoke generator and the laser Doppler velocimeter are turned on, the distance between the specimen and the smoke nozzle 202 in the horizontal direction of the wind tunnel is adjusted, and the test section is determined; then the wind tunnel flow is turned on, the distance between the smoke nozzle 202 and the specimen in the vertical direction of the wind tunnel is adjusted, and the laser Doppler velocimeter reading is observed to achieve the maximum tracer particle concentration and the best flow field stability.

[0041] According to the wind tunnel laser Doppler velocimeter tracer particle release device of the first aspect of the present invention, laser Doppler velocimeter flow field measurement is carried out in a large-size nozzle wind tunnel environment, and the relative position between the smoke nozzle 202 and the specimen can be adjusted in the horizontal and vertical directions of the wind tunnel; in this way, the test section can be determined by adjusting the horizontal distance of the specimen relative to the smoke nozzle 202, and different test sections can be determined by adjusting different horizontal distances of the specimen relative to the smoke nozzle 202; and by adjusting the longitudinal distance of the smoke nozzle 202 relative to the specimen, the maximum tracer particle concentration and the best flow field stability can be achieved; the velocity of the pure water smoke ejected from the smoke nozzle 202 can be adjusted by changing the injection flow rate of the pure water smoke, and the turbulence of the flow in the measured space area, i.e., the space around the specimen, can be reduced by the smoke guide rod 2 after the pure water smoke is ejected, so as to maximize the number of tracer particles effectively measured by the pure water smoke in the measured space area and the flow field stability, and realize the stable measurement of the laser Doppler velocimeter.

[0042] In some embodiments, the support 1 includes a support frame 101 and a specimen fixing rod 102. The support frame 101 is fixed to the wind tunnel, the specimen fixing rod 102 extends transversely along the wind tunnel and is fixed to the support frame 101, and one end of the specimen fixing rod 102 is used to fix the specimen. Therefore, during the test, the specimen is fixed on one end of the specimen fixing rod 102, which can avoid being exposed to the viewing angle of the laser Doppler and prevent the guide rod from affecting the flow field.

[0043] In some embodiments, a specimen clamp 103 is provided at one end of the specimen fixing rod 102, and the specimen clamp 103 is used to clamp the specimen. The specimen is fixed by the specimen clamp 103, which is easy to operate and reliable to fix.

[0044] In some embodiments, the specimen fixing rod 102 is movably fixed on the support frame 101 in the horizontal direction of the wind tunnel, or the specimen fixing rod is a telescopic rod, thereby achieving adjustable horizontal distance between the specimen and the smoke nozzle 202.

[0045] In some embodiments, the smoke guide rod 2 is fixed to the support frame 101 to prevent the distance between the smoke nozzle 202 and the test piece from being kept constant during the test, which is beneficial to the stability of the flow around the test piece. It should be noted that in some other embodiments, the smoke guide rod can also be fixed in the wind tunnel by other structures.

[0046] In some embodiments, the support frame 101 includes a chassis 1011 and a vertical pole 1012, the chassis 1011 is fixed to the bottom of the wind tunnel, the lower end of the vertical pole 1012 is fixed to the chassis 1011, the specimen fixing rod 102 can be fixed to the vertical pole 1012 in a transversely movable manner, and the smoke guide rod 2 can be fixed to the vertical pole 1012 in a longitudinally movable manner.

[0047] In some embodiments, one end of the smoke guide rod 2 is provided with a smoke inlet 201, and the smoke inlet 201 is connected to the pure water smoke generator. That is, one end of the smoke guide rod 2 is connected to the pure water smoke generator through the smoke inlet 201, and the connection operation is convenient.

[0048] In some embodiments, the smoke guide rod 2 is L-shaped, which can achieve the goal of not interfering with the windward flow field, that is, reducing the flow turbulence in the measured space area, that is, the space around the test piece after the pure water smoke is sprayed out.

[0049] In some embodiments, the smoke guide rod 2 is movably fixed on the support frame 101 in the longitudinal direction of the wind tunnel. Thus, the longitudinal distance of the smoke nozzle 202 relative to the test piece can be adjusted.

[0050] In some embodiments, the nozzle cross-sectional area of ​​the wind tunnel is greater than 10 square meters, that is, the wind tunnel is a large-size nozzle wind tunnel.

[0051] The second aspect of the present invention also provides a test method for a wind tunnel laser Doppler velocimeter tracer particle release device.

[0052] According to the second aspect of the present invention, a method for testing a wind tunnel laser Doppler velocimeter tracer particle release device is performed using the wind tunnel laser Doppler velocimeter tracer particle release device according to the first aspect of the present invention, and includes the following steps:

[0053] Fix the specimen on the bracket 1;

[0054] Then, the pure water smoke generator and the laser Doppler velocimeter are turned on, and the distance between the test piece and the smoke nozzle 202 in the horizontal direction of the wind tunnel is adjusted to determine the test section;

[0055] The wind tunnel flow is then turned on, the distance of the smoke nozzle 202 relative to the test piece in the longitudinal direction of the wind tunnel is adjusted, and the reading of the laser Doppler velocimeter is observed.

[0056] According to the testing method of the wind tunnel laser Doppler velocimeter tracer particle releasing device according to the second aspect of the present invention, since the wind tunnel laser Doppler velocimeter tracer particle releasing device of the first aspect of the present invention is used for testing, the testing method of the wind tunnel laser Doppler velocimeter tracer particle releasing device according to the second aspect of the present invention has the same technical effect as the wind tunnel laser Doppler velocimeter tracer particle releasing device of the first aspect of the present invention, which will not be repeated here.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0058] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wind tunnel laser Doppler velocimeter tracer particle release device, characterized in that: include: Wind tunnel; A bracket, wherein the bracket is fixed in the wind tunnel and is used to fix the test piece; A pure water smoke generator, wherein the pure water smoke generator is used to generate pure water smoke with tracer particles; A smoke guide rod, one end of which is connected to the pure water smoke generator, and the other end of which is provided with a smoke nozzle, which faces downstream in the longitudinal direction of the wind tunnel and is located upstream of the test piece; the relative position between the smoke nozzle and the test piece is adjustable in the transverse and longitudinal directions of the wind tunnel; Laser Doppler velocimeter, the laser multispectral rib velocimeter is used to measure the flow field around the test piece.

2. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 1, characterized in that: The bracket comprises a support frame and a specimen fixing rod, wherein the support frame is fixed to the wind tunnel, the specimen fixing rod extends transversely along the wind tunnel and is fixed to the support frame, and one end of the specimen fixing rod is used for fixing the specimen.

3. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 2, characterized in that: A specimen clamp is provided at one end of the specimen fixing rod, and the specimen clamp is used to clamp the specimen.

4. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 2, characterized in that: The specimen fixing rod is movably fixed on the support frame in the transverse direction of the wind tunnel, or the specimen fixing rod is a telescopic rod.

5. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 2, characterized in that: The smoke guide rod is fixed to the support frame.

6. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 2, characterized in that: One end of the smoke guide rod is provided with a smoke inlet, and the smoke inlet is connected to the pure water smoke generating device.

7. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 2, characterized in that: The smoke guide rod is L-shaped.

8. The wind tunnel laser Doppler velocimeter tracer particle release device according to claim 2, characterized in that: The smoke guide rod is movably fixed on the support frame in the longitudinal direction of the wind tunnel.

9. A method for testing a wind tunnel laser Doppler velocimeter tracer particle release device, characterized in that: The wind tunnel laser Doppler velocimeter tracer particle release device according to any one of claims 1 to 8 is used for testing, comprising the following steps: Fixing the test piece on the bracket; Then, the pure water smoke generator and the laser Doppler velocimeter are turned on, and the distance between the test piece and the smoke nozzle in the horizontal direction of the wind tunnel is adjusted to determine the test section; The wind tunnel inflow is then opened, the distance of the smoke nozzle relative to the test piece in the longitudinal direction of the wind tunnel is adjusted, and the reading of the laser Doppler velocimeter is observed.

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