CN117030186A

CN117030186A - Experimental device and method for foreign object impact two-dimensional bifurcation flow passage under low-speed air flow

Info

Publication number: CN117030186A
Application number: CN202310668689.4A
Authority: CN
Inventors: 罗刚; 周超群; 张峰旗
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2023-06-07
Filing date: 2023-06-07
Publication date: 2023-11-10

Abstract

The invention discloses an experimental device and method for a foreign object to strike a two-dimensional bifurcation runner under low-speed airflow. The test cabin comprises a bifurcation flow passage, one end of the bifurcation flow passage is an opening, the bifurcation flow passage is divided into an upper flow passage and a lower flow passage from the middle part, and the other end of the bifurcation flow passage is provided with two flow passage openings. The bifurcation flow passage is connected with an external object collector, the external object collector is connected with an air extractor, and the air velocity transmitter measures the air velocity at the inlet of the bifurcation flow passage. The air extractor is opened to enable the bifurcation flow passage to reach a set flow rate, foreign objects are emitted by the foreign object emitter to enter the bifurcation flow passage, and the shooting system is utilized to shoot and record the movement process of the foreign objects. The invention has simple structure and can realize the experiment of impacting foreign matters into the air inlet channel in the air inlet state.

Description

Experimental device and method for foreign object impact two-dimensional bifurcation flow passage under low-speed air flow

Technical Field

The invention relates to the field of foreign object impact and fluid-solid coupling of an aeroengine air inlet, in particular to a device and a method for an experiment of foreign object impact two-dimensional bifurcation flow passage under low-speed airflow.

Background

When the aeroengine works, foreign objects such as birds are easy to inhale into the core engine, so that engine parts are damaged, the performance of the engine is reduced or stopped, and flight safety is threatened. Therefore, the linear civil aircraft mostly adopts an air inlet channel with a tubular bypass channel with certain foreign matter removing capacity, the bypass channel is additionally arranged in the air inlet channel of the new-generation turboprop aircraft, and foreign matters exceeding the swallowing limit of the engine are expected to enter the channel and be discharged under the action of air flow, so that the influence on the performance of the engine is reduced, the safety is ensured, and the power requirement of the aircraft in the severe environment flight can be met. But it cannot be guaranteed that all foreign objects can be discharged from the bypass channel, and once foreign objects enter the core machine from the main channel to strike the engine core component, unexpected losses are caused.

At present, aiming at the problem of foreign matter impact of an inlet channel with a bypass channel in an air inlet state, the track simulation of the foreign matters such as borneol, metal particles and the like is developed in the research at home and abroad, and the research on the aspect of experiments is less, and the related test device is lacking.

Therefore, it is necessary to design an experimental device that can strike the intake duct with foreign matters in the intake state.

Disclosure of Invention

The invention aims to: aiming at the defects, the invention provides an experimental device and method for the impact of foreign matters on a two-dimensional bifurcation runner under low-speed air flow.

The technical scheme is as follows: in order to solve the problems, the invention adopts a two-dimensional bifurcation runner experimental device for the impact of foreign objects under low-speed airflow, and comprises a foreign object emitter, a wind speed transmitter, a test cabin, a foreign object collector, an air exhaust device and a shooting system; the test cabin comprises a bifurcation flow passage, one end of the bifurcation flow passage is an opening without bifurcation, the bifurcation flow passage is divided into an upper flow passage and a lower flow passage from the middle part, and the other end of the bifurcation flow passage is provided with two flow passage openings; the air flow rate measuring device is arranged at one non-bifurcation end of the bifurcation flow channel and used for measuring the air flow rate at the non-bifurcation opening; the upper flow passage opening after bifurcation of the bifurcation flow passage is connected with one end of an external object collector, the other end of the external object collector is connected with an air exhaust device, the external object emitter is used for emitting external objects to enter the bifurcation flow passage from the opening without bifurcation, and the shooting system is positioned on one side of the test cabin and shoots and records the movement process of the external objects.

Further, the foreign object emitter comprises a high-pressure air storage tank, an adjusting valve and a gun barrel; one end of the regulating valve is connected with the high-pressure air storage tank, the other end of the regulating valve is connected with the gun barrel, and a bullet support is arranged in the gun barrel.

Further, the wind speed transducer comprises a wind speed measuring probe and a wind speed detecting rod, and the wind speed measuring probe is positioned at one end of the wind speed detecting rod; the wind speed detection rod penetrates through and is fixed on the upper surface of the bifurcation flow passage, and the wind speed measurement probe is positioned in the bifurcation flow passage.

Furthermore, the side surface of the test cabin is made of transparent materials, and the shooting system is opposite to the transparent materials to shoot the inside of the test cabin.

Further, the test cabin further comprises a fixed support, and the bifurcation runner is arranged on the fixed support.

Further, the foreign object collector comprises a transition square pipe and a foreign object collecting pipe, one end of the transition square pipe is connected with the bifurcation runner, the other end of the transition square pipe is connected with one end of the foreign object collecting pipe, and the other end of the foreign object collecting pipe is connected with the air exhaust device through the reducing device.

Further, the reducing device comprises a square reducing pipe and a round reducing pipe, one end of the square reducing pipe is connected with the foreign matter collecting pipe, the other end of the square reducing pipe is connected with one end of the round reducing pipe, and the other end of the round reducing pipe is connected with the air exhaust device.

Further, the air extractor comprises a blower, a motor and a blower bracket, wherein the blower is fixedly arranged on the blower bracket, and the motor is connected with the blower to drive the blower to rotate.

Further, the photographing system includes a high-speed camera.

The invention also provides an experimental method of the experimental device, which comprises the following steps:

step 1, placing a foreign object; placing the foreign object in a foreign object emitter to wait for emission;

step 2, adjusting a shooting system; opening and adjusting the shooting system to enter a shooting preparation state;

step 3, adjusting the air flow rate in the test cabin; opening the air extractor to work; observing the wind speed displayed by the wind speed transducer; the air extractor is regulated to make the opening of the bifurcation flow channel not bifurcation reach the required air flow rate and be stable; after the flow velocity of the flow field is stable, the wind speed transducer is pulled out;

step 4, launching foreign objects to finish an impact experiment; adjusting the pressure of the gas in the foreign object emitter to the pressure required by the experiment; releasing gas and emitting foreign matters;

step 5, recording the process and parameters of the foreign object impact bifurcation flow passage: the shooting system shoots and records the movement process of the foreign object, and records the impact speed, rebound speed and angle of the foreign object and the phenomenon generated in the impact process in a picture playback mode.

The beneficial effects are that: compared with the prior art, the invention has the remarkable advantages that (1) the structure is simple, and the operation is simple and convenient; the invention uses equipment to be relatively basic, realizes experimental study by using simple equipment, and has simple experimental method and no operation difficulty; (2) The square and round reducer pipe is connected with the blower, so that the stability of the flow field in the bifurcation runner is well controlled; (3) The whole process of foreign object impact is recorded by utilizing high-speed photography, so that experimental results are recorded truly, and further analysis and research on the influence condition of low-speed airflow on foreign object motion are facilitated.

Drawings

FIG. 1 is a schematic view of the general structure of the present invention;

FIG. 2 is a schematic diagram of an emitter and test chamber system of the present invention;

figure 3 is a schematic view of a foreign object collector and suction device of the present invention.

Detailed Description

As shown in fig. 1, an experimental device for a two-dimensional bifurcation flow channel of an external object under low-speed airflow in this embodiment includes an external object emitter 7, an air speed transducer 8, a fixed bracket 6, a bifurcation flow channel 1, a transition square tube 2, an external object collecting tube 3, an air extracting device 4 and a high-speed camera 16. As shown in fig. 2, the foreign object launcher 7 includes a high-pressure air tank 9, a regulating valve 10, and a gun barrel 11; one end of the regulating valve 10 is connected with the high-pressure air storage tank 9, the other end is connected with the gun barrel 11, and a bullet support is arranged in the gun barrel 11 and used for placing foreign objects. The wind speed transducer 8 comprises a wind speed measuring probe 12 and a wind speed detecting rod 14, wherein the wind speed measuring probe 12 is positioned at one end of the wind speed detecting rod 14; the wind speed detecting rod 14 penetrates through and is fixed on the upper surface of the bifurcation flow passage 1 by a flange 13, and the wind speed measuring probe 12 is positioned inside the bifurcation flow passage 1. One end of the bifurcation flow channel 1 is an opening which is not bifurcated, the bifurcation flow channel is divided into an upper flow channel and a lower flow channel from the middle part, and the other end of the bifurcation flow channel 1 is provided with two flow channel openings. The foreign object emitter 7 emits the foreign object from the non-branched opening into the branched flow passage 1. The two sides of the bifurcation runner 1 are made of transparent organic glass 15 with good light transmittance, and a transparent material is adopted to provide good light transmittance conditions for shooting the movement of foreign objects on one hand, so that the view of the high-speed camera 16 is not blocked; meanwhile, the protection can be provided for test personnel and other equipment when foreign objects are emitted, and damage to personnel or equipment caused by broken fragments of the foreign objects due to collision can be avoided; and a pipeline with closed periphery can be formed, so that the flow field in the bifurcation runner 1 is easier to stabilize. The bifurcation runner 1 is fixedly mounted on a fixed bracket 6. The high-speed camera 16 is positioned at one side of the bifurcation runner 1 and is opposite to the transparent organic glass 15 to shoot the inside of the test cabin, and record the movement process of foreign objects.

The upper portion runner opening after bifurcation of bifurcation runner 1 is connected with transition side pipe 2 one end, and transition side pipe 2 other end is connected with foreign object collecting pipe 3 one end, and the foreign object falls into foreign object collecting pipe 3 through transition side pipe 2 under the action of gravity, prevents that the foreign object from flushing into air exhaust device 4, causes equipment damage. The other end of the foreign matter collecting pipe 3 is connected with one end of a square reducing pipe 17, the other end of the square reducing pipe 17 is connected with one end of a circular reducing pipe 18, and the other end of the circular reducing pipe 18 is connected with the air extractor 4. The air extractor 4 comprises a blower 19, a motor 20 and a blower bracket 21, wherein the blower 19 is fixedly arranged on the blower bracket 21, and the motor 20 is connected with the blower 19 to drive the blower 19 to rotate. As shown in fig. 3, the transition square tube 2, the foreign material collecting tube 3, the square reducing tube 17, the circular reducing tube 18 and the air extractor 4 are all installed on the experiment table 6.

The embodiment also provides an experimental method for the foreign object to strike the two-dimensional bifurcation flow passage experimental device under the low-speed air flow, which comprises the following steps:

step 1, placing a foreign object; the foreign objects are placed on the bullet holders matched in size, and the bullet holders are placed in the gun barrel 11 to wait for firing.

Step 2, adjusting a shooting system; the high-speed camera 16 is turned on and adjusted to enter a shooting ready state.

Step 3, adjusting the air flow rate in the test cabin; the motor 20 is turned on to drive the blower 19 to work; observing the wind speed displayed by the wind speed transducer 8; the blower 19 is regulated to ensure that the non-bifurcation opening of the bifurcation runner 1 reaches the required air flow rate and is stable; after the flow velocity of the flow field is stable, the wind speed transducer 8 is pulled out, so that the flow field is stable and uniform, and the risk of collision between the wind speed transducer 8 and foreign objects is avoided.

Step 4, launching foreign objects to finish an impact experiment; regulating the gas pressure in the gas storage tank 9; setting the regulating valve 10 to a pressure required for the experiment; the gas storage tank 9 is filled with gas, and the released gas pushes the bullet holder to launch foreign objects.

Step 5, recording the process and parameters of the foreign object impact bifurcation flow passage: the high-speed camera 16 photographs and records the movement process of the foreign object, and records the impact speed, rebound speed and angle of the foreign object and the phenomenon generated by the impact process in a picture playback mode. The flow field flow velocity and the foreign object incident speed can also be changed, multiple groups of data are recorded through the high-speed camera 16, and the influence of air flow on the foreign objects under various working conditions is analyzed.

Claims

1. The experimental device for the two-dimensional bifurcation runner of foreign object impact under low-speed airflow is characterized by comprising a foreign object emitter (7), a wind speed transmitter (8), a test cabin, a foreign object collector, an air extractor (4) and a shooting system; the test cabin comprises a bifurcation flow channel (1), one end of the bifurcation flow channel (1) is an opening without bifurcation, the bifurcation flow channel is divided into an upper flow channel and a lower flow channel from the middle part, and the other end of the bifurcation flow channel (1) is provided with two flow channel openings; the air flow rate measuring device is arranged at one non-bifurcation end of the bifurcation runner (1) and used for measuring the air flow rate at the non-bifurcation opening; the upper flow passage opening after bifurcation of the bifurcation flow passage (1) is connected with one end of an external object collector, the other end of the external object collector is connected with an air extractor (4), an external object emitter (7) is used for emitting external objects to enter the bifurcation flow passage (1) from an opening without bifurcation, a shooting system is positioned on one side of a test cabin, and shooting records the movement process of the external objects.

2. The experimental device according to claim 1, characterized in that the foreign object emitter (7) comprises a high pressure gas tank (9), a regulating valve (10) and a gun barrel (11); one end of the regulating valve (10) is connected with the high-pressure air storage tank (9), the other end of the regulating valve is connected with the gun barrel (11), and a bullet support is arranged in the gun barrel (11).

3. The experimental device according to claim 2, characterized in that the wind speed transducer (8) comprises a wind speed measuring probe (12) and a wind speed detecting rod (14), the wind speed measuring probe (12) being located at one end of the wind speed detecting rod (14); the wind speed detection rod (14) penetrates through and is fixed on the upper surface of the bifurcation flow channel (1), and the wind speed measurement probe (12) is positioned inside the bifurcation flow channel (1).

4. A test device according to claim 3, wherein the sides of the test chamber are made of transparent material, and the photographing system photographs the interior of the test chamber directly against the transparent material.

5. The laboratory device according to claim 4, characterized in that the laboratory cabin further comprises a fixed support (6), the bifurcation flow channel (1) being mounted on the fixed support (6).

6. The experimental device according to claim 5, wherein the foreign object collector comprises a transition square tube (2) and a foreign object collecting tube (3), one end of the transition square tube (2) is connected with the bifurcation runner (1), the other end of the transition square tube (2) is connected with one end of the foreign object collecting tube (3), and the other end of the foreign object collecting tube (3) is connected with the air exhaust device (4) through the reducing device.

7. The experimental device according to claim 6, wherein the reducing device comprises a square reducing pipe (17) and a circular reducing pipe (18), one end of the square reducing pipe (17) is connected with the foreign object collecting pipe (3), the other end of the square reducing pipe (17) is connected with one end of the circular reducing pipe (18), and the other end of the circular reducing pipe (18) is connected with the air extracting device (4).

8. The experimental device according to claim 7, wherein the air extractor (4) comprises a blower (19), a motor (20) and a blower bracket (21), the blower (19) is fixedly installed on the blower bracket (21), and the motor (20) is connected with the blower (19) to drive the blower (19) to rotate.

9. The experimental device according to claim 8, characterized in that the shooting system comprises a high-speed camera (16).

10. A method of testing an assay device according to any one of claims 1 to 9, comprising the steps of:

step 1, placing a foreign object; placing a foreign object in a foreign object emitter (7) to wait for emission;

step 3, adjusting the air flow rate in the test cabin; opening the air extracting device (4) to work; observing the wind speed displayed by a wind speed transducer (8); the air extractor (4) is regulated to enable the non-bifurcation opening of the bifurcation runner (1) to reach the required air flow rate and to be stable; after the flow velocity of the flow field is stable, the wind speed transducer (8) is pulled out;

step 4, launching foreign objects to finish an impact experiment; adjusting the gas pressure in the foreign object emitter (7) to the pressure required by the experiment; releasing gas and emitting foreign matters;