Low-heat-conduction constant-temperature supporting structure for Doppler differential interferometer
By combining a low thermal conductivity support structure and a constant temperature structure, the problem of temperature fluctuation affecting the optical path position of the Doppler differential interferometer was solved, achieving reduced heat conduction and constant temperature, thus improving the accuracy of wind speed inversion.
Patent Information
- Application Number
- CN202411137145.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2026-03-03
AI Technical Summary
The optical path position of a Doppler differential interferometer is easily affected by external temperature fluctuations, leading to a decrease in the accuracy of wind speed inversion.
The device employs a low thermal conductivity support structure and a constant temperature structure, which are fixed together by screws to support the Doppler differential interferometer. The low thermal conductivity support structure consists of a base, a cover plate, a support column, and a boss. The constant temperature structure consists of a metal heating cover, an incident and exit window assembly, an active heating element, and a passive thermal insulation layer, which reduces heat conduction and maintains a constant temperature.
This reduces heat conduction, keeps the differential interferometer in a specified temperature environment, prevents changes in the optical path position, and improves the accuracy of wind speed inversion.
Smart Images
Figure CN121595024A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of wind measurement equipment technology, specifically relating to a low thermal conductivity constant temperature support structure for a Doppler differential interferometer. Background Technology
[0002] The working principle of a Doppler differential interferometer is as follows: Figure 1 As shown, the target spectral line with Doppler frequency shift passes through aperture 1, is collimated by relay mirror 2, and enters Doppler differential interferometer 3. Imaging mirror 4 images the interference fringes onto detector 5. Wind speed can then be inverted by monitoring the Doppler frequency shift. As a core component of the wind measurement equipment, if the absolute position of the Doppler differential interferometer in the optical path changes, such as a translation along the X-axis (along the direction of the interference fringes), the resulting interference fringe translation will be incorporated into the Doppler frequency shift, affecting the accuracy of wind speed inversion.
[0003] The structure of a Doppler differential interferometer is as follows: Figure 2 As shown, it is made of a variety of optical materials bonded together, including two beam splitters, two field-widening prisms 7, and two gratings 8, which are bonded together by a first spacer element 9, a second spacer element 10, and a third spacer element 11. Among them, the beam splitters 6 and gratings 8 are made of the same optical material, the two field-widening prisms 7 are made of the same optical material, the spacer element 10 is made of a low coefficient of thermal expansion optical material, the spacer element 9 is made of a high coefficient of thermal expansion optical material, and the spacer element 11 is made of a low coefficient of thermal expansion optical material.
[0004] When the external temperature fluctuates, the structural metal material of the fixed differential interferometer will deform with the temperature fluctuation, which will cause the position of the differential interferometer in the optical path to change. Therefore, in order to reduce the influence of ambient temperature on the position of the differential interferometer, the differential interferometer needs to be in an environment with a constant temperature. Summary of the Invention
[0005] To reduce the impact of external temperature fluctuations on differential interferometers, this invention proposes a low thermal conductivity isothermal support structure for Doppler differential interferometers.
[0006] The technical solution adopted by this invention to solve its technical problem is:
[0007] A low thermal conductivity isothermal support structure for a Doppler differential interferometer includes a low thermal conductivity support structure and an isothermal structure.
[0008] in:
[0009] The Doppler differential interferometer is fixed on a low thermal conductivity support structure. The low thermal conductivity support structure and the constant temperature structure are fixedly connected by screws. The constant temperature structure and the low thermal conductivity support structure surround the Doppler differential interferometer.
[0010] The low thermal conductivity support structure includes a base, a cover plate, a support column, an upper boss, and a lower boss.
[0011] One end of the support column is fixed to the base, and the other end of the support column is fixedly connected to the cover plate. Both the upper and lower bosses include wings and bosses. The wings of the upper boss are fixedly connected to the cover plate, and the wings of the lower boss are fixedly connected to the base. The bosses of both the upper and lower bosses are bonded and fixed to the beam splitter prism.
[0012] The constant temperature structure includes a metal heating cover, an incident window assembly and an exit window assembly, an active heating element, and a passive thermal insulation layer.
[0013] Both the incident window assembly and the exit window assembly are fixed to a metal heating cover. An active heating element is attached to the outside of the metal heating cover. A passive thermal insulation layer is attached to the outside of the active heating element to reduce heat exchange between the external environment and the metal heating cover. Both the incident window assembly and the exit window assembly include window glass, a glass frame, and a glass cover. A second silicone rubber is applied around the perimeter of the window glass, located within the glass frame. A first silicone rubber is applied to the end face of the glass cover to press the window glass firmly. An active heating element is attached to the outer frame surface of the glass cover.
[0014] The aforementioned low thermal conductivity constant temperature support structure has four support columns.
[0015] The aforementioned low thermal conductivity constant temperature support structure has three upper and three lower bosses.
[0016] In the aforementioned low thermal conductivity constant temperature support structure, the boss is bonded and fixed to the beam splitter prism using structural epoxy adhesive.
[0017] In the aforementioned low thermal conductivity constant temperature support structure, the boss is cylindrical, the wings are connected to the side wall of the boss, and the three wings are evenly distributed along the circumference of the side wall of the boss.
[0018] In the aforementioned low thermal conductivity constant temperature support structure, the base and cover plate are made of a metal material with low thermal conductivity, the boss is made of a different metal material than the base and cover plate, and the boss and the beam splitter are made of a metal material with the same coefficient of linear expansion. The support column is made of a metal material with low thermal conductivity.
[0019] The aforementioned low thermal conductivity constant temperature support structure has a support column made of a metal material with low thermal conductivity (such as titanium alloy).
[0020] In the aforementioned low thermal conductivity constant temperature support structure, the lengths of the four pillars are guaranteed to be consistent, and the length H of the pillars must ensure that the height H1 of the low thermal conductivity constant temperature support structure is less than the thickness H2 of the beam splitter in the Doppler differential interferometer, and the difference between H2 and H1 is greater than 0.5mm.
[0021] In the aforementioned low thermal conductivity constant temperature support structure, the wing thickness of the upper boss is less than the wing thickness of the lower boss.
[0022] In the aforementioned low thermal conductivity constant temperature support structure, the metal heating cover is made of a high thermal conductivity metal material.
[0023] In the aforementioned low thermal conductivity constant temperature support structure, the incident window assembly and the exit window assembly are distributed at 90°.
[0024] The beneficial effects of this invention are:
[0025] A low thermal conductivity isothermal support structure for a Doppler differential interferometer can achieve three functions: first, reduce heat conduction and minimize the impact of ambient temperature fluctuations on the differential interferometer; second, provide a specified constant temperature environment system for the differential interferometer; and third, ensure that the Doppler differential interferometer does not undergo translation along the X-axis in the optical path. Attached Figure Description
[0026] Figure 1 This is a schematic diagram illustrating the working principle of a Doppler differential interferometer.
[0027] Figure 2 It is a Doppler differential interferometer;
[0028] Figure 3 This is a schematic diagram of a low thermal conductivity support structure according to an embodiment of the present invention;
[0029] Figure 4 This is a diagram showing the location of the support pillars;
[0030] Figure 5 This is a schematic diagram showing the positions of the upper and lower bosses;
[0031] Figure 6 This is a schematic diagram of the wing position, where h represents the wing thickness;
[0032] Figure 7 This is a schematic diagram of the support column, upper boss, and lower boss structure. H is the length of the support column, and H1 is the height of the low thermal conductivity constant temperature support structure.
[0033] Figure 8 This is a stereoscopic view of the beam splitter, where H2 is the thickness of the beam splitter.
[0034] Figure 9 This is a schematic diagram of a constant temperature structure;
[0035] Figure 10 This is a schematic diagram of the isothermal structure entrance window assembly and exit window assembly;
[0036] Figure 11 It is a cross-sectional view of the isothermal structure entrance window assembly and exit window assembly.
[0037] Reference numerals: 1. Aperture, 2. Relay mirror, 3. Doppler differential interferometer, 4. Imaging mirror, 5. Detector, 6. Beam splitter, 7. Broadening prism, 8. Grating, 9. First spacer element, 10. Second spacer element, 11. Third spacer element, 12. Base, 13. Cover plate, 14. Support column, 15. Upper boss, 16. Lower boss, 17. Wing, 18. Metal heating cover, 19. Entrance window assembly, 20. Exit window assembly, 21. Window glass, 22. Glass frame, 23. Glass cover, 24. First silicone rubber, 25. Second silicone rubber, 26. Outer frame surface. Detailed Implementation
[0038] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0039] Example 1
[0040] A low thermal conductivity isothermal support structure for a Doppler differential interferometer includes a low thermal conductivity support structure and an isothermal structure.
[0041] The low thermal conductivity support structure reduces heat exchange between the Doppler differential interferometer 3 and the external environment through heat conduction, and ensures that the Doppler differential interferometer does not experience thermal translation along the X-axis. For example... Figures 3 to 8As shown, the low thermal conductivity support structure includes a base 12, a cover plate 13, four pillars 14, and upper and lower bosses 15 and 16. There are six bosses in total (three bosses define one plane). Each boss is bonded to the beam splitter 6 with structural epoxy adhesive, and each boss is connected to the structural frame (cover plate and base) via three wings 17 (three wings define one positioning surface). This low thermal conductivity structure has two advantages: firstly, the bosses are not in direct contact with the structural frame, but are connected by three wings, which reduces the contact area between components, increases thermal resistance, and reduces heat transfer. Secondly, the boss, base, and cover can be made of different metal materials. The boss, which is in direct contact with the beam splitter 6, must be made of a metal with the same coefficient of linear expansion as the beam splitter prism. The base and cover can be made of metals with low thermal conductivity. Flexible links of the same size are designed at the wings. Their function is to ensure that when the ambient temperature fluctuates, the thermal deformation caused by the different coefficients of thermal expansion of different metals is located at the flexible links at the wings. Since the wings 17 are evenly distributed, it ensures that the Doppler differential interferometer only produces thermal deformation in the Z direction. Similarly, the four pillars 14 used to connect the base and cover can also be made of metals with low thermal conductivity (such as titanium alloy). The low-temperature thermally conductive support structure reduces the metal's heat conduction by reducing the contact area and selecting metals with low thermal conductivity. The thickness h of the upper and lower sets of boss wings 17 is different. The thickness h of the upper set of boss wings is smaller than that of the lower set of boss wings because the main function of the lower set of bosses is to support and position the interferometer. Meanwhile, the four pillars 14 are of the same length, and the length H of the pillars 14 must ensure that the height H1 of the low thermal conductivity constant temperature support structure is less than the thickness H2 of the beam splitter 6 in the Doppler differential interferometer 3, and the difference between H2 and H1 is greater than 0.5mm, so as to ensure that after the Doppler differential interferometer 3 is installed, the low thermal conductivity constant temperature support structure has a certain pre-tightening force on the Doppler differential interferometer 3.
[0042] The operating temperature of the Doppler differential interferometer 3 is higher than that of the external environment. The function of the thermostatic structure is to maintain the operating temperature of the Doppler differential interferometer 3 at a predetermined temperature value, while reducing the heat transfer from the Doppler differential interferometer to the outside through thermal radiation or thermal convection, so as to ensure that the operating temperature fluctuation of the differential interferometer is within a very small range.
[0043] isothermal structure such as Figures 9 to 11As shown, the system includes a metal heating cover 18, an entrance window assembly 19, and an exit window assembly 20. The constant temperature structure is fixed to the base 12 with screws. The metal heating cover 18 is made of a high thermal conductivity metal. An active heating element is attached to the outside of the metal heating cover 18 to maintain the operating temperature of the interferometer. A passive thermal insulation layer is attached to the outside of the active heating element on the outside of the metal heating cover 18 to reduce heat exchange between the external environment and the metal heating cover 18. According to the optical path design, the entrance window assembly 19 and the exit window assembly 20 are fixed on the heating cover 18 and are distributed at 90°. The exit window and the entrance window have the same structure, both including a window glass 21, a glass frame 22, and a glass cover 23. The window glass 21 is coated with a second silicone rubber 25 around its perimeter and inserted into the glass frame 22. The end face of the glass cover 23 is coated with a first silicone rubber 24 to press the window glass 21 tightly. This structure ensures that the window glass 21 can freely expand by compressing the silicone rubber under temperature fluctuations, thereby reducing the thermal stress caused by thermal deformation. Heating pads are attached to the outer frame surface 26 of the glass cover 23 to heat the window glass. By controlling the temperature at the window glass, the heat radiated outward through the window glass is reduced.
[0044] The low thermal conductivity support structure and the constant temperature structure are combined, and the heating element makes its working temperature higher than the ambient temperature, and achieves a temperature fluctuation of 0.1℃ for the metal heating cover and 0.01℃ for the internal interferometer.
Claims
1. A low thermal conductivity isothermal support structure for a Doppler differential interferometer, characterized in that, Including low thermal conductivity support structures and constant temperature structures; in: The Doppler differential interferometer (3) is fixed on a low thermal conductivity support structure. The low thermal conductivity support structure and the constant temperature structure are fixedly connected by screws. The constant temperature structure and the low thermal conductivity support structure surround the Doppler differential interferometer (3). The low thermal conductivity support structure includes a base (12), a cover plate (13), a support column (14), an upper boss (15), and a lower boss (16); One end of the support column (14) is fixed to the base (12), and the other end of the support column (14) is fixedly connected to the cover plate (13); the upper boss (15) and the lower boss (16) both include wings (17) and bosses; the wings (17) of the upper boss (15) are fixedly connected to the cover plate (13), and the wings (17) of the lower boss (16) are fixedly connected to the base (12); the bosses of the upper boss (15) and the lower boss (16) are both bonded and fixed to the beam splitter (6); The constant temperature structure includes a metal heating cover (18), an incident window assembly (19) and an exit window assembly (20), an active heating element, and a passive heat insulation layer; The incident window assembly (19) and the exit window assembly (20) are both fixed on the metal heating cover (18); An active heating element is attached to the outside of the metal heating cover (18); a passive heat insulation layer is attached to the outside of the active heating element, which is used to reduce the heat exchange between the external environment and the metal heating cover (18); both the incident window assembly (19) and the exit window assembly (20) include a window glass (21), a glass frame (22) and a glass cover (23); the window glass (21) is coated with a second silicone rubber (25) around its perimeter and is located inside the glass frame (22); the end face of the glass cover (23) is coated with a first silicone rubber (24) to press the window glass (21) tightly; an active heating element is attached to the outer frame surface (26) of the glass cover (23).
2. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, Four support pillars (14) are provided. The lengths of the four support pillars (14) must be consistent. The length H of the support pillars (14) must ensure that the height H1 of the low thermal conductivity constant temperature support structure is less than the thickness H2 of the beam splitter (6) in the Doppler differential interferometer (3). The difference between H2 and H1 is greater than 0.5 mm. This ensures that after the Doppler differential interferometer (3) is installed, the wings (17) of the upper boss (15) will deform, and the low thermal conductivity constant temperature support structure will have a certain preload on the Doppler differential interferometer (3).
3. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The upper boss (15) and the lower boss (16) are each provided with 3.
4. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The boss is bonded and fixed to the beam splitter (6) by structural epoxy adhesive.
5. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The boss is cylindrical, and the wings (17) are connected to the side wall of the boss. The three wings (17) are evenly distributed along the circumference of the side wall of the boss.
6. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The base (12) and cover plate (13) are made of metal with low thermal conductivity. The boss is made of a different metal than the base (12) and cover plate (13). The boss and the beam splitter (6) are made of metal with the same coefficient of linear expansion. The support column (14) is made of metal with low thermal conductivity.
7. The low thermal conductivity constant temperature support structure according to claim 6, characterized in that, The support column (14) is made of a metal material with low thermal conductivity.
8. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The thickness of the wing (17) of the upper boss (15) is less than the thickness of the wing (17) of the lower boss (16).
9. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The metal heating cover (18) is made of a high thermal conductivity metal material.
10. The low thermal conductivity constant temperature support structure according to claim 1, characterized in that, The incident window assembly (19) and the exit window assembly (20) are arranged at 90°.