CN114136633B

CN114136633B - Air supply cavity structure for increasing infrared visual angle of high-level air inlet rotary disc cavity test system of aircraft engine

Info

Publication number: CN114136633B
Application number: CN202111435692.9A
Authority: CN
Inventors: 邱天; 丁水汀; 邓长春
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-08-12
Anticipated expiration: 2041-11-29
Also published as: CN114136633A

Abstract

The invention discloses an air supply cavity structure for increasing the infrared visual angle of a high-level air inlet rotary disc cavity test system of an aircraft engine. The air outlet is circular and is positioned at the high radius position of the closed end surface of the cylinder and used for deflecting the flow direction of the test airflow by a specific angle. An infrared perspective window consisting of a concave lens and a convex lens is arranged in the center of the closed end face of the air supply cavity, an infrared thermal imager is arranged in the hollow area in the middle of the air supply cavity, and the infrared thermal imager can shoot a turbine disk test piece through the infrared perspective window to obtain a temperature field of the turbine disk test piece. The infrared perspective window is used for changing an infrared transmission route radiated by the turbine disk test piece, and breaking through infrared light path transmission limitation caused by special structure requirements of the test piece and insufficient view field angles of the traditional thermal infrared imager, so that the traditional thermal infrared imager can receive infrared radiation of the whole rotor, and a complete turbine disk test piece temperature field is obtained.

Description

Air supply cavity structure for increasing infrared visual angle of high-level air inlet rotary disc cavity test system of aircraft engine

Technical Field

The invention relates to the field of aero-engines, in particular to an air supply cavity structure for increasing an infrared visual angle of a high-level air inlet rotary disc cavity test system of an aero-engine.

Background

The rotary disk cavity system of the aircraft engine bears the cooling work of a typical aircraft engine life-limiting part turbine disk, and has important significance on the safety and the service life of the aircraft engine. Therefore, the heat exchange characteristic test research of the rotary disc cavity system of the aircraft engine is always the key research content in the engine development process.

The temperature distribution of the surface of a turbine disk test piece needs to be measured in the heat exchange characteristic research of the aero-engine rotating disk cavity test system. In the traditional research of the heat exchange test of the rotating disk cavity, a commonly used turbine disk temperature testing method comprises thermochromatic liquid crystal temperature measurement, thermocouple temperature measurement and thermal infrared imager temperature measurement. The thermochromatic liquid crystal temperature measurement technology can obtain a temperature field of the turbine disc, but the temperature measurement range is small, and the thermochromatic liquid crystal temperature measurement technology is particularly difficult to apply to working conditions with large temperature gradients. And the thermochromic liquid crystals are expensive and cannot be recycled, so that the test cost is obviously increased. The thermocouple is cheap, has a wide temperature testing range, can be recycled, and can only measure the temperature of a single point. If the temperature field of the whole test piece is to be obtained, particularly when the non-uniform characteristic of the circumferential distribution of the temperature of the test piece needs to be captured, dense thermocouple temperature measuring points need to be arranged on the surface of the test piece of the turbine disk, and the approximate temperature field of the surface of the test piece can be obtained. However, if the thermocouple measuring points are arranged too densely, a large number of lead holes need to be formed in the turbine disc test piece, so that the structure and the stress distribution state of the test piece can be obviously changed, and the test effect and the safety of a test system are harmfully influenced. Meanwhile, when the thermocouple is used for testing the temperature of the rotating turbine disk test piece, a slip ring electricity leading device is matched to convert a rotating test signal into a static signal and then input the static signal into an acquisition system. The slip ring current leading device is expensive and has a certain service life, which also increases the cost of experimental research. The application of the infrared thermal imaging technology as a non-contact temperature measurement method cannot influence the structure of a turbine disk test piece. The temperature measurement range is wide, the temperature measurement device can be recycled, and a complete turbine disc temperature field and a transient evolution process of the temperature field can be obtained. Can effectively avoid a plurality of problems in the application process of the thermochromatic liquid crystal and the thermocouple.

Although the infrared thermal imaging temperature measurement technology has many advantages, the method needs to provide an infrared transparent window structure on the stator of the rotating disk cavity test piece in the application process, so that part of rotating disk cavity test systems with special structures cannot normally apply the temperature measurement technology. Such as the high-level pre-swirl inlet disk cavity system shown in fig. 1. And an air outlet pre-rotation hole is formed in the high-radius position of the pre-rotation disc. When the thermal infrared imager is used for measuring the temperature of the turbine disk test piece D, the infrared perspective window C can be only arranged at the central position of the prerotation disk, so that the thermal imager lens penetrates through the infrared perspective window C for testing. Due to the special requirements on the structure of the test piece, the distance between the stator piece and the turbine disk test piece is small, meanwhile, due to the limitation of strength, the area of the infrared perspective window cannot be too large, and the infrared transmission path of the turbine disk test piece radiating outwards can be limited. In addition, the field angle beta of the thermal infrared imager testing system E is limited, the field angle of the standard lens of the existing thermal infrared imager is not more than 30 degrees, and the field angle of the infrared wide-angle lens sold in the market is not more than 50 degrees. Due to the fact that the traditional infrared temperature measurement method is adopted in the rotating disk cavity test system with the structure, the thermal imager can only shoot the position near the central area of the turbine disk test piece, and the temperature field of the high-radius area cannot be obtained, as shown in fig. 2.

Disclosure of Invention

Aiming at the problems, the invention provides the air supply cavity structure for increasing the infrared visual angle of the high-order air inlet rotary disk cavity test system of the aircraft engine, which can provide test air flow with a certain pre-rotation angle for the rotary disk cavity test system, and simultaneously changes the infrared transmission path through the designed infrared lens group, so that the traditional thermal imager can receive all infrared radiation of a turbine disk test piece, and the temperature field of the whole turbine disk test piece is obtained.

The invention relates to an air supply cavity structure for increasing the infrared visual angle of a high-order air intake rotary disk cavity test system of an aircraft engine, which is provided with a semi-closed double-layer cylindrical structure drum barrel, a pre-rotating disk and an infrared lens group.

An air flow channel is formed between the double-layer cylindrical structures of the drum barrel, and an infrared thermal imager is arranged in the drum barrel; the rear end of the drum barrel is circumferentially provided with an air inlet pipe which is the same as the air flow channel; a prewhirl disc is fixedly arranged at the front end of the drum barrel; an infrared lens set is arranged in the central opening of the pre-rotating disc. Through prerotation disk, upstream airflow channel and air inlet pipe, the airflow direction is changed, and the test airflow with a certain presuspension angle is provided for the experimental system with the rotary disk cavity.

The infrared lens group consists of a concave lens positioned at the outer side and a convex lens positioned at the inner side. The infrared lens group can change the transmission path of infrared rays in the rotating disk cavity test piece, so that all infrared radiation on the surface of the turbine disk test piece in the rotating disk cavity test piece can be received by the thermal infrared imager through the lens group, and the temperature field of the whole turbine disk test piece can be obtained.

The invention has the advantages that:

1. the air supply cavity structure for increasing the infrared visual angle of the high-order air inlet rotary disk cavity test system of the aircraft engine can provide test airflow with a certain pre-rotation angle for the rotary disk cavity test system, and the central lens group can change the infrared ray transmission path, so that the effect of increasing the visual field angle of the traditional infrared thermal imager is achieved.

2. According to the air supply cavity structure for increasing the infrared visual angle of the high-order air intake rotating disk cavity test system of the aircraft engine, the concave lens and the convex lens in the lens group are processed by using infrared materials, the visual field angle can be determined by designing the focal length combination of the two lenses according to actual requirements, the temperature field test of the whole turbine disk test piece can be realized, and the circumferential non-uniform distribution characteristics of the temperature evolution process and the temperature of the turbine disk test piece are captured.

Drawings

FIG. 1 is a schematic structural view of a conventional aircraft engine high-position pre-swirl air inlet rotary disc cavity test piece;

FIG. 2 is a schematic diagram of an infrared ray transmission route of a conventional aircraft engine high-position pre-rotation air inlet rotary disk cavity test piece;

FIG. 3 is a schematic structural view of an air supply chamber for increasing an infrared viewing angle of a high-order air intake rotary disk chamber test system of an aircraft engine, provided by the invention;

fig. 4 is a schematic sectional view of an air supply cavity structure for increasing an infrared viewing angle of a high-level air inlet rotary disk cavity test system of an aircraft engine.

FIG. 5 is a schematic view of the thermal infrared imager mounting platform in position inside the inner drum.

FIG. 6 is a schematic diagram of the working principle of an infrared lens group in an air supply cavity structure for increasing the infrared visual angle of a high-order air intake rotary disk cavity test system of an aircraft engine.

FIG. 7 is a photograph showing the temperature measurement effect of the original lens of the thermal infrared imager.

FIG. 8 shows the temperature measurement effect of the present invention combined with a thermal infrared imager.

In the figure:

1-drum component 2-infrared lens group 3-prerotation disk

4-thermal infrared imager 5-test airflow channel 6-paint spraying point

7-thermal infrared imager temperature value taking point 8 connecting hole 101-inner drum barrel

102-outer drum barrel 103-circular ring structure bottom surface 104-air inlet pipe structure

105-thermal imager mounting platform 201-lens group housing 202-concave lens

203-convex lens 301-prerotation hole

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention relates to an air supply cavity structure for increasing the infrared visual angle of a high-order air inlet rotary disk cavity test system of an aircraft engine, which comprises a drum part 1, an infrared lens group 2, a pre-rotary disk 3 and an infrared thermal imager 4, and is shown in figures 3 and 4.

The drum part 1 is of a double-layer drum structure, and the middle part of the double-layer drum is provided with a test air flow channel 5. Since the drum member 1 having the above-described structure cannot be directly processed, the drum member 1 is processed and formed in the following manner in the present invention: firstly, selecting a drum barrel blank capable of meeting the size of a drum part 1 required by machining, and machining a cylindrical inner drum barrel 101 and outer drum barrel 102 structure by utilizing a turning machining mode, wherein the inner diameter of the inner drum barrel 101 is determined according to the size of a thermal infrared imager 4 used in a test, so that the thermal infrared imager 4 can be placed in the inner drum barrel 101. Then, a circular ring structure bottom surface 103 is processed, and the peripheral direction of the outer edge of the circular ring structure bottom surface 103 is welded and fixed with the peripheral direction of the tail end of the outer drum 102; the circumferential direction of the inner edge of the bottom surface 103 of the circular ring structure and the circumferential direction of the tail end of the inner drum 101 are welded and fixed, and finally the semi-closed double-layer drum part 1 is formed integrally.

The outer drum 102 is circumferentially provided with a plurality of air inlet structures 104 near its end which communicate with the test air flow channel 5. The diameter, circumferential number and length of the air inlet pipe structure 104 are determined according to actual air supply requirements. An outward-turned annular flange mounting edge is welded at the front end of the outer drum barrel 101 in the circumferential direction and used for connecting the pre-turning disc 3.

A horizontal thermal imager mounting platform 105 is welded to the middle section of the inner drum 101, as shown in fig. 5, for mounting the thermal infrared imager 4. An inward flange mounting edge is welded at the front end of the inner drum barrel 101 in the circumferential direction and is used for connecting the pre-turning disc 3.

The prewhirl plate 3 is a circular disc, is coaxially arranged with the drum part 1, is attached to the mounting edges of the annular flanges at the front ends of the outer layer drum barrel 102 and the inner layer drum barrel 101, and is screwed with the connecting holes 8 formed on the mounting edges of the annular flanges in a matching manner by screws distributed at equal angles at intervals in the circumferential direction, so that the prewhirl plate 3 is fixed on the front end surface of the drum part 1; and the peripheral direction of the outer edge of the pre-rotating disc 3 is flush with the outer edge of the annular flange mounting edge of the outer-layer drum barrel 102. The high radius position of the pre-rotating disc 3 is provided with pre-rotating air outlets 301 communicated with the test air flow channel 5 at equal angular intervals in the circumferential direction, and the radius positions, the number and the aperture of the pre-selecting air outlets 301 are determined according to the actual air supply requirement. The pre-rotation air outlet 301 is formed by drilling, the pre-rotation angle alpha is an included angle between the axis of the pre-rotation air outlet 301 and the normal of the pre-rotation disc 3, and alpha is larger than or equal to 0 degree and smaller than or equal to 85 degrees. Through prewhirl 3 and upstream test air flow channel 5 and intake pipe structure 104, change the air current direction, to the carousel chamber experimental system, provide the test air current of certain overhang angle in advance. The center of the pre-rotating disc 3 is processed with a two-step circular hole structure by turning for mounting the infrared lens group 2.

The infrared lens group 2 is composed of an outer lens group housing 201 and an inner infrared lens. The lens group housing 201 is a cylindrical structure, and a shoulder is formed in the circumferential direction of the outer wall. The lens group shell 201 is embedded in a step hole at the center of the pre-rotating disc 3 and is bonded and fixed; axial positioning between the lens stack housing 201 and the stepped bore is achieved by a shoulder.

The infrared lens includes a concave lens 202 and a convex lens 203. The concave lens 202 is embedded and fixed on the inner and outer sides of the lens group shell 201; the convex lens 203 is embedded and fixed inside the lens group housing 201. The concave lens 202 and the convex lens 203 are processed by using materials with infrared penetration capability, such as infrared germanium glass; the viewing field angle of the infrared lens group 2 is 50-180 degrees, and the specific angle is determined according to the actual shooting requirement.

The infrared lens group 2 can change the transmission path of infrared rays in the rotating disk cavity test piece, so that all infrared radiation on the surface of the turbine disk test piece in the rotating disk cavity test piece can be received by the thermal infrared imager 4 through the lens group, and the temperature field of the whole turbine disk test piece can be obtained, as shown in fig. 6.

For the turbine disk chamber test piece, the turbine disk test piece D shown in fig. 1 is independent of the present invention. The remaining structure of the rotating disk chamber test piece is included in the present invention, as shown by the pre-rotation disk 3 in FIG. 1. In practical application, the stator air supply system serving as the high-position pre-swirl air inlet rotary disk cavity test piece of the aircraft engine supplies air flow with a specific flow direction to the rotary disk cavity test piece shown in the figure 1. Meanwhile, the infrared lens group 2 is arranged at the center of the pre-rotating disc 3 and used for changing an infrared transmission path and expanding an infrared view field angle. An thermal imager mounting platform 105 which is horizontally arranged is welded on the inner-layer drum barrel 101, and the thermal infrared imager 4 is mounted on the inner-layer drum barrel, so that the lens of the thermal infrared imager 4 is ensured to be coaxial with the two lenses, and the axial distance can be adjusted according to actual requirements; the infrared lens group 2 can be used for testing the surface temperature field of the turbine disk test piece.

The application of the invention adds two infrared lenses for the original lens of the thermal infrared imager 4, which can change the intensity of infrared rays received by the original infrared receiving system of the thermal infrared imager 4 to a certain extent, so that the test result has a certain difference compared with the original standard lens, and therefore, a combined test system formed by the invention and the standard thermal infrared imager needs to be calibrated. The calibration method is as shown in fig. 7 and 8, and paint with a large difference from the surface emissivity of the turbine disk test piece is used for making a spraying point 10 on the surface of the test piece, so that the positions of the thermal imager temperature sampling point 11 and the paint spraying point 10 are kept consistent. Utilize the induction heater to heat turbine disk test piece dish edge under the room temperature environment, turbine disk test piece slowly rotates in the heating process, guarantees to be heated evenly. In the process of increasing the surface temperature of the turbine disk test piece, the thermal infrared imager 4 is independently used for recording the evolution rule data of the temperature along with the time under the state that the air supply cavity is not suitable for the invention. And heating the turbine disk test piece again under the conditions of the same room temperature initial environment, the same heating power and the same rotating speed, changing an infrared ray propagation path by using the gas supply cavity structure in the temperature evolution process, measuring the temperature by using the thermal infrared imager 4 arranged in the gas supply cavity, and recording the data of each temperature measuring point along with the change of time. And comparing and correcting the recorded data with the previously recorded data to finish the correction of the infrared intensity change received by the thermal infrared imager 4 introduced by the invention.

The thermal infrared imager 4 and the air supply cavity structure are independently adopted, the test results measured at the same distance from the turbine disk test piece are shown in fig. 7 and 8, and the infrared lens group 2 in the invention lifts the angle of the field of view of the thermal infrared imager 4 from 30 degrees to 110 degrees. Fig. 7 shows the test result of the lens of the thermal infrared imager 4 alone after the stator structure of the test piece of the rotating disk cavity is removed, but only about 50% of the area of the temperature field of the turbine disk can be shot in this state. FIG. 8 shows the temperature measurement result of the thermal infrared imager 4 in the air supply cavity of the invention, in this state, the static part of the test piece of the rotating disk cavity does not need to be removed, the integrity of the test piece is ensured, and the area of the temperature field of the turbine disk can be shot by more than 80%.

Claims

1. The utility model provides an increase air feed chamber structure at high-order carousel chamber test system infrared visual angle that admits air of aeroengine which characterized in that: the device comprises a semi-closed double-layer cylindrical structure drum barrel, a pre-rotating disc and an infrared lens group;

an air flow channel is formed between the double-layer cylindrical structures of the drum barrel, and an infrared thermal imager is arranged in the drum barrel; the rear end of the drum barrel is circumferentially provided with an air inlet pipe which is the same as the air flow channel; a prewhirl disc is fixedly arranged at the front end of the drum barrel; an infrared lens set is arranged in a central opening of the pre-rotating disc;

the infrared lens group consists of a concave lens positioned at the outer side and a convex lens positioned at the inner side.

2. An air supply cavity structure for increasing the infrared visual angle of a high-level air inlet rotary disk cavity test system of an aircraft engine as claimed in claim 1, characterized in that: the prerotation angle alpha of the prerotation hole is an included angle between the axis of the hole and the normal of the prerotation disc, and alpha is more than or equal to 0 degree and less than or equal to 85 degrees.

3. An air supply cavity structure for increasing the infrared visual angle of a high-level air inlet rotary disk cavity test system of an aircraft engine as claimed in claim 1, characterized in that: the viewing field angle of the infrared lens group is 50-180 degrees.

4. An air supply cavity structure for increasing the infrared visual angle of a high-level air inlet rotary disk cavity test system of an aircraft engine as claimed in claim 1, characterized in that: the drum barrel processing mode is as follows: firstly, selecting a drum barrel blank capable of meeting the processing requirement on the size of a drum barrel, and processing a cylindrical inner drum barrel and outer drum barrel structure by utilizing a turning processing mode, wherein the inner diameter of the inner drum barrel is determined according to the size of an infrared thermal imager used in a test, so that the infrared thermal imager can be placed in the inner drum barrel; then processing a bottom surface of the circular ring structure, and welding and fixing the peripheral direction of the outer edge of the bottom surface of the circular ring structure and the peripheral direction of the tail end of the outer drum; and welding and fixing the circumferential direction of the inner edge of the bottom surface of the circular ring structure and the circumferential direction of the tail end of the inner drum barrel to finally form the semi-closed double-layer drum barrel part.

5. An air supply cavity structure for increasing the infrared visual angle of a high-level air inlet rotary disk cavity test system of an aircraft engine as claimed in claim 1, characterized in that: the thermal infrared imager is arranged on a thermal infrared imager mounting platform designed in the drum barrel, and a lens of the thermal infrared imager is coaxial with the infrared lens group.

6. An air supply cavity structure for increasing the infrared visual angle of a high-level air inlet rotary disk cavity test system of an aircraft engine as claimed in claim 1, characterized in that: the infrared lens set is arranged in a lens set shell embedded in a stepped hole formed in the center of the prerotation disc.