High enthalpy shock wave wind tunnel tube multi-parameter measurement test device

Abstract

The present invention belongs to the technical field of shock tunnel tests, and discloses a multi-parameter measurement test device in a high-enthalpy shock tunnel tube. The multi-parameter measurement test device is installed in the driven section of the shock tube, and includes a front high-pressure transition section, a high-pressure visual section, and a rear high-pressure transition section that are sequentially connected by flanges from front to back. The multi-parameter measurement test device uses built-in circular tube thick-walled optical glass for non-contact optical measurement, which avoids the influence of changes in the internal flow channel on the flow field while ensuring pressure safety; the corrective lens arranged on the outside of the optical glass avoids the problem of circular tube imaging distortion, thereby obtaining more effective test data; at the same time, combined with the reserved surface laser incident window, line laser incident and receiving interface, pressure sensor interface, and heat flow sensor interface, it is used for multi-parameter measurement of wave system structure, components, pressure, heat flow, etc. flowing in the shock tube, and has engineering practical value.

Description

Technical Field

[0001] The invention belongs to the technical field of shock wave wind tunnel tests, and in particular relates to a multi-parameter measurement test device in a high enthalpy shock wave wind tunnel tube. Background Art

[0002] High enthalpy shock wind tunnels have the ability to simulate total temperature and total pressure simultaneously, and are the main equipment to support the development of aircraft / weapons and optimize the aerodynamic thermal layout of aircraft. With the development of supersonic flight technology, people have put forward higher requirements for the simulation of total temperature and total pressure in ground tests. In terms of air-breathing power tests, the incoming flow medium is also required to be pure air, making the operation process in the high enthalpy shock wind tunnel tube more complicated. Therefore, mastering the complex flow mechanism and law in the tube under the influence of thermochemical non-equilibrium is the basis for giving full play to the equipment capabilities and obtaining precise test data.

[0003] At present, there are few studies on the complex flow phenomena and laws in high-enthalpy shock wave wind tunnels. Measuring the shock wave Mach number and total pressure only through pressure sensors cannot effectively evaluate the relevant flow phenomena and laws. Therefore, it is of great significance to measure the flow parameters in high-enthalpy shock wave wind tunnels and reveal the relevant phenomena and laws.

[0004] Currently, there is an urgent need to develop a multi-parameter measurement test device inside a high-enthalpy shock wave wind tunnel. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a multi-parameter measurement test device in a high enthalpy shock wave wind tunnel tube, so as to establish an engineering foundation for conducting complex flow research in a high enthalpy shock wave wind tunnel tube.

[0006] The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device of the present invention is installed in the driven section of the shock tube, and comprises a front high-pressure transition section, a high-pressure visual section and a rear high-pressure transition section connected in sequence from front to rear through flanges; the front high-pressure transition section, the high-pressure visual section and the rear high-pressure transition section are all tube bodies, and a central cavity penetrating from front to back is arranged on the central axis, and the central cavity constitutes an inner flow channel;

[0007] On the upper pipe wall of the front high-pressure transition section and the rear high-pressure transition section, a plurality of pressure sensor interfaces are evenly arranged from front to back; on the lower pipe wall of the front high-pressure transition section and the rear high-pressure transition section, a plurality of heat flow sensor interfaces corresponding to the pressure sensor interfaces are evenly arranged from front to back;

[0008] A circular tubular optical glass is embedded in the front and rear ends of the high-voltage visual section respectively. The optical glass is fixed on the end face by a glass pressing plate. The optical glass and the end face of the high-voltage visual section and the glass pressing plate are sealed by a graphite gasket I. An imaging correction lens is symmetrically arranged on the left and right sides of each optical glass. The optical glass and the imaging correction lens are isolated by an isolation step arranged on the tube wall of the high-voltage visual section. The isolation step and the imaging correction lens are sealed by a graphite gasket II. The imaging correction lens is fixed on the outer wall surface of the high-voltage visual section by a lens pressing plate. A silicone rubber gasket is arranged between the imaging correction lens and the lens pressing plate. An optical window is opened on the outer wall surface of the high-voltage visual section outside the imaging correction lens. A total of 4 optical windows are opened on the high-voltage visual section, and the 4 optical windows are symmetrical left and right and front and back.

[0009] A surface laser incident window is opened on the tube wall above the optical glass in front. The surface laser incident window is a rectangular window. The surface laser incident window is used as the laser incident port for the planar laser induced fluorescence (PLIF) measurement technology. Combined with the optical window, it measures the flow velocity of the internal flow field in the high-pressure visible section and the mixing condition of the contact surface.

[0010] Two sets of symmetrical linear laser incident and receiving interfaces are opened on the upper and lower tube walls of the rear optical glass; the linear laser incident and receiving interfaces are used for tunable semiconductor laser absorption spectroscopy TDLAS measurement technology to measure the composition and temperature of the internal flow field in the high-pressure visible section.

[0011] Furthermore, the inner flow channel diameters of the front high-pressure transition section, the high-pressure visible section and the rear high-pressure transition section are the same as the inner diameter of the shock tube, there is no reverse step on the inner wall surface at the connection, and the forward step height is less than 0.05 mm.

[0012] Furthermore, the inner diameter of the optical glass is the same as that of the shock tube, and the material is calcium fluoride glass.

[0013] Furthermore, the thickness of the graphite gasket I is 1 mm, the thickness of the graphite gasket II is 0.5 mm, and the thickness of the silicone rubber gasket is 0.5 mm.

[0014] Furthermore, the imaging correction lens is a positive meniscus cylindrical lens with an edge thickness greater than 3 mm, and the material is calcium fluoride glass.

[0015] Furthermore, the optical glass and the imaging correction lens have the same focal length but opposite directions.

[0016] Furthermore, the width of the isolation gap between the optical glass and the imaging correction lens is L, 3mm≤L≤10mm, and the width of the isolation gap is adjusted by replacing graphite gaskets II of different thicknesses.

[0017] Furthermore, the inclination angle of the linear laser incident and receiving interface is greater than 5°.

[0018] Furthermore, a high-frequency pressure sensor is installed in the pressure sensor interface to measure the pressure along the front high-pressure transition section and the rear high-pressure transition section; a high-frequency heat flow sensor is installed in the heat flow sensor interface to measure the heat flow along the front high-pressure transition section and the rear high-pressure transition section.

[0019] The single-side tube wall of the optical glass 12 is a concentric meniscus lens, and the front and rear main surfaces of the concentric meniscus lens are both on a vertical plane passing through the center of the circle. The focal length of the optical glass is fitted and calculated using a thin lens imaging calculation formula, and the specific steps are as follows:

[0020] First, the outer surface image distance is obtained according to the thin lens imaging formula l 1;

[0021] Secondly, the outer surface image distance l 1 plus the tube wall thickness as the inner surface object distance L 2. Calculate the inner surface image distance according to the thin lens imaging formula l 2;

[0022] Finally, the inner surface image distance l 2. Combine the main surface position to obtain the focal length of the optical glass.

[0023] The high-enthalpy shock wave wind tunnel tube multi-parameter measurement test device of the present invention adopts built-in circular tube thick-walled optical glass for non-contact optical measurement, which avoids the influence of internal flow channel changes on the flow field while ensuring pressure-bearing safety; the corrective lens arranged on the outside of the optical glass avoids the problem of circular tube imaging distortion, thereby obtaining more effective test data; at the same time, combined with the reserved surface laser incident window, line laser incident and receiving interface, pressure sensor interface, heat flow sensor interface, it is used for multi-parameter measurement of wave system structure, component, pressure and heat flow of the flow in the shock wave tube, and has engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram (stereoscopic diagram) of a multi-parameter measurement test device in a high enthalpy shock wave wind tunnel tube of the present invention;

[0025] Figure 2 It is a schematic diagram (main cross-sectional view) of a multi-parameter measurement test device in a high enthalpy shock wave wind tunnel tube of the present invention;

[0026] Figure 3 It is a schematic diagram of the multi-parameter measurement test device in the high enthalpy shock wave wind tunnel tube of the present invention (AA cross-sectional view).

[0027] In the figure, 1. front high-pressure transition section; 2. high-pressure visible section; 3. optical window; 4. rear high-pressure transition section; 5. lens pressure plate; 6. line laser incident and receiving interface; 7. surface laser incident window; 8. pressure sensor interface; 9. heat flux sensor interface; 10. graphite gasket I; 11. glass pressure plate; 12. optical glass; 13. graphite gasket II; 14. silicone rubber gasket; 15. imaging correction lens. DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0029] like Figure 1~Figure 3 As shown, the high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device of the present invention is installed in the driven section of the shock tube, and includes a front high-pressure transition section 1, a high-pressure visual section 2 and a rear high-pressure transition section 4 which are sequentially connected from front to back through flanges; the front high-pressure transition section 1, the high-pressure visual section 2 and the rear high-pressure transition section 4 are all tube bodies, and a central cavity which runs through the front and back is arranged on the central axis, and the central cavity constitutes an inner flow channel;

[0030] On the upper pipe wall of the front high-pressure transition section 1 and the rear high-pressure transition section 4, a plurality of pressure sensor interfaces 8 are evenly arranged from front to back; on the lower pipe wall of the front high-pressure transition section 1 and the rear high-pressure transition section 4, a plurality of heat flow sensor interfaces 9 corresponding to the pressure sensor interfaces 8 are evenly arranged from front to back;

[0031] A tubular optical glass 12 is embedded in the front and rear ends of the high-voltage visual section 2, respectively. The optical glass 12 is fixed on the end face by a glass pressing plate 11. The optical glass 12 and the end face of the high-voltage visual section 2 and the glass pressing plate 11 are sealed by a graphite gasket Ⅰ10. An imaging correction lens 15 is symmetrically arranged on the left and right sides of each optical glass 12. The optical glass 12 and the imaging correction lens 15 are isolated by an isolation step arranged on the tube wall of the high-voltage visual section 2. The isolation step and the imaging correction lens 15 are sealed by a graphite gasket Ⅱ13. The imaging correction lens 15 is fixed on the end face of the high-voltage visual section 2 by a lens pressing plate 5. On the outer wall surface of the high-pressure visual section 2, a silicone rubber gasket 14 is arranged between the imaging correction lens 15 and the lens pressure plate 5; the imaging correction lens 15 is used for correcting the imaging distortion of the circular tubular optical glass 12 to improve the effective field of view, and at the same time serves as a second layer of protective glass to prevent a large amount of air from entering the shock tube and reacting after the optical glass 12 is accidentally broken; an optical window 3 is provided on the outer wall surface of the high-pressure visual section 2 outside the imaging correction lens 15; a total of 4 optical windows 3 are provided on the high-pressure visual section 2, and the 4 optical windows 3 are symmetrical left and right and front and back; the optical window 3 can be used for flow field display measurement such as high-speed schlieren or high-speed photography;

[0032] A surface laser incident window 7 is opened on the tube wall above the front optical glass 12, and the surface laser incident window 7 is a rectangular window; the surface laser incident window 7 is used as the laser incident port of the planar laser induced fluorescence PLIF measurement technology, and is combined with the optical window 3 to measure the flow velocity of the internal flow field and the mixing condition of the contact surface of the high-pressure visible section 2;

[0033] Two sets of line laser incident and receiving interfaces 6 are opened on the upper and lower tube walls of the rear optical glass 12 symmetrically; the line laser incident and receiving interfaces 6 are used for tunable semiconductor laser absorption spectroscopy TDLAS measurement technology to measure the composition and temperature of the internal flow field of the high-pressure visible section 2.

[0034] Furthermore, the inner flow channel diameters of the front high-pressure transition section 1, the high-pressure visible section 2 and the rear high-pressure transition section 4 are the same as the inner diameter of the shock tube, there is no reverse step on the inner wall surface at the connection, and the forward step height is less than 0.05 mm.

[0035] Furthermore, the inner diameter of the optical glass 12 is the same as that of the shock tube, and the material is calcium fluoride glass.

[0036] Furthermore, the thickness of the graphite gasket I10 is 1 mm, the thickness of the graphite gasket II13 is 0.5 mm, and the thickness of the silicone rubber gasket 14 is 0.5 mm.

[0037] Furthermore, the imaging correction lens 15 is a positive meniscus cylindrical lens with an edge thickness greater than 3 mm, and the material is calcium fluoride glass.

[0038] Furthermore, the optical glass 12 and the imaging correction lens 15 have the same focal length but opposite directions.

[0039] Furthermore, the width of the isolation gap between the optical glass 12 and the imaging correction lens 15 is L, 3mm≤L≤10mm, and the width of the isolation gap is adjusted by replacing the graphite gasket II 13 of different thicknesses.

[0040] Furthermore, the inclination angle of the linear laser incident and receiving interface 6 is greater than 5°.

[0041] Furthermore, a high-frequency pressure sensor is installed in the pressure sensor interface 8 for measuring the pressure along the front high-pressure transition section 1 and the rear high-pressure transition section 4; a high-frequency heat flow sensor is installed in the heat flow sensor interface 9 for measuring the heat flow along the front high-pressure transition section 1 and the rear high-pressure transition section 4.

[0042] Furthermore, the single-side tube wall of the optical glass 12 is a concentric meniscus lens, and the front and rear main surfaces of the concentric meniscus lens are both on a vertical plane passing through the center of the circle. The focal length of the optical glass is fitted and calculated using a thin lens imaging calculation formula, and the specific steps are as follows:

[0043] First, the outer surface image distance is obtained according to the thin lens imaging formula l 1;

[0044] Secondly, the outer surface image distance l 1 plus the tube wall thickness as the inner surface object distance L 2. Calculate the inner surface image distance according to the thin lens imaging formula l 2;

[0045] Finally, the inner surface image distance l 2 The focal length of the optical glass 12 is obtained in combination with the position of the main surface.

[0046] Embodiment 1: This embodiment is a hydrogen driven high enthalpy shock wind tunnel, the driving section gas is hydrogen, the driven section gas is pure air, the maximum total pressure is 28MPa, the maximum total temperature is 3200K, the inner diameter of the shock tube is 80mm, and the high enthalpy shock wind tunnel in-tube multi-parameter measurement test device of the present invention is installed at the tail end of the driven section.

[0047] The inner flow channel diameters of the front high-pressure transition section 1, the high-pressure visual section 2 and the rear high-pressure transition section 4 are 80 mm; the inner diameter of the optical glass 12 is 80 mm and the length is 160 mm; the edge thickness of the imaging correction lens 15 is 3 mm; the width of the isolation gap between the optical glass 12 and the imaging correction lens 15 is 5 mm;

[0048] The optical window 3 is 100 mm×100 mm, the surface laser incident window 7 is 100 mm×20 mm, the inner diameter of the line laser incident and receiving interface 6 is 20 mm, and the inclination angle is 15°.

[0049] The above embodiments only express typical implementations of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention's patent shall be subject to the attached claims.

Claims

1. A multi-parameter measurement test device in a high enthalpy shock wave wind tunnel tube, characterized in that: The multi-parameter measurement test device is installed on the driven section of the shock tube, and comprises a front high-pressure transition section (1), a high-pressure visual section (2) and a rear high-pressure transition section (4) which are sequentially connected from front to rear by flanges; the front high-pressure transition section (1), the high-pressure visual section (2) and the rear high-pressure transition section (4) are all tube bodies, and a central cavity which passes through the front and rear is provided on the central axis, and the central cavity constitutes an inner flow channel; A plurality of pressure sensor interfaces (8) are evenly arranged from front to back on the upper pipe wall of the front high-pressure transition section (1) and the rear high-pressure transition section (4); a plurality of heat flow sensor interfaces (9) corresponding one to one to the pressure sensor interfaces (8) are evenly arranged from front to back on the lower pipe wall of the front high-pressure transition section (1) and the rear high-pressure transition section (4); A circular tubular optical glass (12) is respectively embedded at the front and rear ends of the high-voltage visual section (2); the optical glass (12) is fixed on the end surface via a glass pressing plate (11); the optical glass (12) and the end surface of the high-voltage visual section (2) and the glass pressing plate (11) are sealed via a graphite gasket I (10); an imaging correction lens (15) is symmetrically arranged on the left and right sides of each optical glass (12); the optical glass (12) and the imaging correction lens (15) are isolated via an isolation step arranged on the tube wall of the high-voltage visual section (2). The isolation step and the imaging correction lens (15) are sealed by a graphite gasket II (13); the imaging correction lens (15) is fixed on the outer wall surface of the high-voltage visual section (2) by a lens pressure plate (5), and a silicone rubber gasket (14) is arranged between the imaging correction lens (15) and the lens pressure plate (5); an optical window (3) is provided on the outer wall surface of the high-voltage visual section (2) outside the imaging correction lens (15); a total of four optical windows (3) are provided on the high-voltage visual section (2), and the four optical windows (3) are symmetrical left-right and front-back; The imaging correction lens (15) is a positive meniscus cylindrical lens; A surface laser incident window (7) is opened on the tube wall above the front optical glass (12), and the surface laser incident window (7) is a rectangular window; the surface laser incident window (7) serves as a laser incident port for the planar laser induced fluorescence (PLIF) measurement technology, and is combined with the optical window (3) to measure the internal flow field velocity and contact surface mixing conditions of the high-pressure visible section (2); Two groups of line laser incident and receiving interfaces (6) are provided on the upper and lower tube walls of the rear optical glass (12) in an upper and lower symmetrical manner; the line laser incident and receiving interfaces (6) are used for tunable semiconductor laser absorption spectroscopy TDLAS measurement technology to measure the composition and temperature of the internal flow field of the high-pressure visible section (2).

2. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The inner flow channel diameters of the front high-pressure transition section (1), the high-pressure visible section (2) and the rear high-pressure transition section (4) are the same as the inner diameter of the shock tube, the inner wall surface at the connection has no reverse step, and the forward step height is less than 0.05 mm.

3. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The inner diameter of the optical glass (12) is the same as the inner diameter of the shock tube, and the material is calcium fluoride glass.

4. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The thickness of the graphite gasket I (10) is 1 mm, the thickness of the graphite gasket II (13) is 0.5 mm, and the thickness of the silicone rubber gasket (14) is 0.5 mm.

5. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The edge thickness of the imaging correction lens (15) is greater than 3 mm and the material is calcium fluoride glass.

6. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The optical glass (12) and the imaging correction lens (15) have the same focal length but opposite directions.

7. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The width of the isolation gap between the optical glass (12) and the imaging correction lens (15) is L, 3mm≤L≤10mm, and the width of the isolation gap is adjusted by replacing graphite gaskets II (13) of different thicknesses.

8. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The inclination angle of the linear laser incident and receiving interface (6) is greater than 5°.

9. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: A high-frequency pressure sensor is installed in the pressure sensor interface (8) for measuring the pressure along the front high-pressure transition section (1) and the rear high-pressure transition section (4); a high-frequency heat flow sensor is installed in the heat flow sensor interface (9) for measuring the heat flow along the front high-pressure transition section (1) and the rear high-pressure transition section (4).

10. The high enthalpy shock wave wind tunnel in-tube multi-parameter measurement test device according to claim 1, characterized in that: The single-side tube wall of the optical glass (12) is a concentric meniscus cylindrical lens with a main surface passing through a vertical plane at the center of the circle. The focal length of the optical glass (12) is fitted and calculated using a thin lens imaging calculation formula. The specific steps are as follows: First, the outer surface image distance is obtained according to the thin lens imaging formula l 1; Secondly, the outer surface image distance l 1 plus the tube wall thickness as the inner surface object distance L 2. Calculate the inner surface image distance according to the thin lens imaging formula l 2; Finally, the inner surface image distance l 2 The focal length of the optical glass (12) is obtained in combination with the position of the principal surface.

Images