Aero-engine combustion chamber three-dimensional high-speed measurement system based on flexible optical fiber bundle

Abstract

The invention discloses a three-dimensional high-speed measurement system for an aero-engine combustion chamber based on flexible optical fiber bundles. The three-dimensional high-speed measurement system comprises a high-speed camera, a group of flexible optical fiber bundles and a plurality of high-temperature-resistant endoscopes, one group of flexible optical fiber bundles consists of a mother optical fiber at one end and a plurality of son optical fibers at the other end; the plurality of sub optical fibers are connected with the plurality of high-temperature-resistant endoscopes in a one-to-one correspondence manner, and the plurality of high-temperature-resistant endoscopes are uniformly arranged on the periphery of a combustion chamber to be measured and inserted into the combustion chamber And the high-speed camera is used for collecting the mother optical fiber signal. The system adopts a flexible optical fiber bundle as a sensor, and can meet the requirements of a severe environment in a combustion chamber of an aero-engine. Meanwhile, the system adopts a single-camera high-speed three-dimensional imaging technology, multiple high-speed cameras do not need to be synchronously controlled, and the experiment cost and the synchronous control difficulty are reduced. Three-dimensional high-speed acquisition is realized; meanwhile, the endoscope is of a heat insulation and vibration resistance structure and can stably work in a combustion chamber of an aero-engine for a long time, and the service life of the endoscope is remarkably prolonged.

Description

Technical Field

[0001] The invention relates to the field of experimental testing devices, and more particularly to a three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle. Background Art

[0002] The combustion chamber is one of the core components of the engine. The reliability, enthusiasm and life of the engine depend to a large extent on the reliability and effectiveness of the combustion chamber. To this end, it is an important task in the development of modern high-performance aircraft to improve the design level of the combustion chamber and develop a combustion chamber with high combustion efficiency, high heat capacity, small heat loss, small flow loss, stable combustion, reliable ignition, long life, low pollutant emissions, high temperature rise, and reasonable outlet temperature distribution. At present, the power propulsion system developed in my country still has a certain gap with foreign countries in terms of thrust-to-weight ratio, combustion efficiency, power performance and pollution emissions. One of the key reasons is that the flow field in the propulsion system is a complex process involving the mutual coupling of chemical reaction flow and heat transfer. The lack of reliable and effective non-contact measurement technology has led to our understanding of the basic phenomena and essential laws of the flow field in the engine is far from enough, which restricts the technical level of the engine. Therefore, realizing multi-field and multi-parameter measurement of the flow field in the engine is of great significance to deeply understand the real state of the combustion chamber and optimize and improve the engine performance.

[0003] At present, traditional two-dimensional optical methods, whether path integral or plane measurement methods, will lack relevant three-dimensional information and lead to inaccurate measurement results. The three-dimensional tomography technology can overcome the limitations of low temporal and spatial resolution brought by scanning, and form the ability to measure three-dimensional parameters of fuel concentration, combustion product component concentration, and flame structure under different working conditions. However, traditional three-dimensional high-speed measurement requires multiple high-speed cameras, the experimental cost is extremely high and the synchronization control is difficult. In addition, the interior of the aircraft engine combustion chamber has the characteristics of high temperature, high pressure and strong vibration, which requires the three-dimensional high-speed measurement system to meet the requirements of high temperature resistance, high pressure resistance, strong stability and not easy to damage.

[0004] Therefore, it is necessary to develop a three-dimensional high-speed measurement system for aircraft engine combustion chamber based on flexible optical fiber bundles. Summary of the invention

[0005] In view of this, the present invention provides a three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle, aiming to solve the above technical problems.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle, comprising: a high-speed camera, a set of flexible optical fiber bundles and a plurality of high-temperature resistant endoscopes;

[0008] The flexible optical fiber bundle is composed of a mother optical fiber at one end and a plurality of sub-optical fibers at the other end; the plurality of sub-optical fibers are connected to a plurality of high-temperature resistant endoscopes in a one-to-one correspondence; the plurality of high-temperature resistant endoscopes are evenly arranged around the combustion chamber to be measured and inserted into the combustion chamber;

[0009] The high-speed camera is used to collect the mother optical fiber signal.

[0010] Furthermore, the high temperature resistant endoscope comprises: a sapphire window, a front end lens, a front end lens barrel, a rear end objective lens, a rear end lens barrel and a cooling jacket;

[0011] Wherein, the sapphire window and the front lens are sequentially installed on one side of the front lens barrel; the front lens is installed in the front lens barrel, and the installation position is adjusted in the front lens barrel according to the field of view angle requirement;

[0012] The front end lens barrel is composed of a metal shell and internal heat insulation materials, which wrap the internal optical elements; the cooling jacket completely wraps the outer periphery of the front end lens barrel;

[0013] The rear end lens barrel is connected to the front end lens barrel by threads, and the rear end lens barrel is composed of a metal shell and internal heat insulation material;

[0014] The rear end lens is installed inside the rear end lens barrel, and its position inside the rear end lens barrel is adjusted according to the position of the front end lens;

[0015] The sub-fiber of the flexible fiber bundle is connected to the rear end lens barrel through a thread, and transmits the optical signal of the combustion chamber to the mother fiber of the flexible fiber bundle.

[0016] Furthermore, the front end lens is a wide-angle lens.

[0017] Furthermore, there are cooling air and cooling water channels inside the cooling jacket.

[0018] Furthermore, the rear end lens is a telephoto lens.

[0019] Furthermore, the optical axes of the front lens and the rear lens are consistent.

[0020] Furthermore, the high-speed camera is used to collect the mother optical fiber signal, and is combined with a three-dimensional tomography algorithm to obtain the three-dimensional flow field characteristics inside the combustion chamber.

[0021] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a three-dimensional high-speed measurement system for the combustion chamber of an aircraft engine based on a flexible optical fiber bundle. The system uses a flexible optical fiber bundle as a sensor, and has the characteristics of high temperature resistance, high pressure resistance, strong stability and not easy to damage, and can meet the requirements of the harsh environment inside the combustion chamber of an aircraft engine. At the same time, the system uses a single-camera high-speed three-dimensional imaging technology, and there is no need to synchronously control multiple high-speed cameras, which reduces the experimental cost and the difficulty of synchronous control. Through this system, high-speed measurement of three-dimensional parameters such as fuel concentration, combustion product component concentration, and flame structure can be achieved, providing an important basis for in-depth understanding of the true state of the combustion chamber and optimizing and improving engine performance.

[0022] The present invention can collect the radiation signal of the flame inside the combustion chamber of the aircraft engine in three dimensions at a low cost and low complexity. At the same time, the endoscope adopts a heat-insulating and vibration-resistant structure, which can work stably for a long time in the combustion chamber of the aircraft engine, significantly improving its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 A schematic structural diagram of a three-dimensional high-speed measurement system for an aero-engine combustion chamber based on a flexible optical fiber bundle provided by the present invention.

[0025] Figure 2 This is a schematic structural diagram of the high temperature resistant endoscope provided by the present invention.

[0026] Description of the drawings: 1 is a high-speed camera, 2 is a flexible optical fiber bundle, 3 is a high-temperature resistant endoscope, 4 is a combustion chamber; 5 is a sapphire window, 6 is a cooling sleeve, 7 is a front end lens, 8 is a front end lens barrel, 9 is a rear end lens, and 10 is a rear end lens barrel. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The embodiment of the present invention discloses a three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle. Figure 1 As shown, each component is in accordance with Figure 1 The structure shown is assembled, including a high-speed camera 1, a group of flexible optical fiber bundles 2 and multiple high-temperature resistant endoscopes 3; a group of flexible optical fiber bundles 1 is composed of a mother optical fiber at one end and multiple sub-optical fibers at the other end; the multiple sub-optical fibers are connected to the multiple high-temperature resistant endoscopes 3 in a one-to-one correspondence, and the multiple high-temperature resistant endoscopes 3 are evenly arranged outside the combustion chamber to be measured and inserted into the combustion chamber 4; the high-speed camera 1 is used to collect the mother optical fiber signal.

[0029] Among them, high temperature resistant endoscope 3, refer to Figure 2 As shown, it includes: a sapphire window 5, a cooling sleeve 6, a front lens 7, a front lens barrel 8, a rear lens 9 and a rear lens barrel 10. The sapphire window 5 and the front lens 7 are sequentially installed on one side of the front lens barrel 8; the front lens 7 is a wide-angle lens, which is installed in the front lens barrel, and the specific position can be adjusted in the front lens barrel according to the field of view requirements.

[0030] The front end barrel 8 is composed of a metal shell and internal insulation material, and wraps the internal optical elements; the cooling sleeve 6 completely wraps the front end barrel 8, and has cooling air and cooling water channels inside; the rear end barrel 10 is connected to the front end barrel 8 by threads, and the rear end barrel 10 is composed of a metal shell and internal insulation material; the rear end lens 9 is a telephoto lens, which is installed inside the rear end barrel, and its position in the rear end barrel 10 is adjusted according to the position of the front end lens 7; the sub-fiber of the flexible optical fiber bundle is connected to the rear end barrel 10 by threads, and transmits the optical signal of the combustion chamber 4 to the mother optical fiber of the flexible optical fiber bundle; the high-speed camera 1 is used to collect the mother optical fiber signal of the flexible optical fiber bundle, and obtains the three-dimensional flow field characteristics inside the combustion chamber in combination with the three-dimensional tomography technology.

[0031] Among them, the front end barrel composed of a metal shell, internal insulation material and a cooling jacket can work continuously in a high temperature and high pressure environment to protect the internal optical components. Sapphire glass is used as the optical window of the front end barrel, which can effectively protect the internal lens under high temperature and high pressure conditions. The position of the front end lens and the rear end lens in the barrel can be adjusted according to the actual measurement field angle requirements.

[0032] like Figure 1 As shown, by combining an endoscope with a flexible optical fiber bundle, the internal optical signals of the combustion chamber at different angles are synchronously converged to the mother optical fiber of the flexible optical fiber bundle through the sub-optical fibers of the flexible optical fiber bundle. By combining a high-speed camera with a flexible optical fiber bundle, a single high-speed camera is used to directly collect the mother optical fiber signal of the flexible optical fiber bundle, and the sub-optical fiber signals of all flexible optical fiber bundles can be synchronously collected.

[0033] Working principle:

[0034] A plurality of high temperature resistant endoscopes 3 are inserted into the combustion chamber 4 of the aircraft engine at different angles, and a sapphire window 5 is installed at the front end of a front end lens barrel 8. The radiation of the flame enters the front end lens barrel 8 from the sapphire window 5, and completes the first imaging through the front end lens 7; then, after the second imaging through the rear end lens 9, it reaches the sub-fiber of the flexible optical fiber bundle 2, and the sub-fibers of the plurality of flexible optical fiber bundles transmit the radiation signal of the flame to the mother optical fiber of the flexible optical fiber bundle; finally, a high-speed camera 1 is used to collect the signal of the mother optical fiber of the flexible optical fiber bundle.

[0035] The three-dimensional high-speed measurement system of the combustion chamber of an aircraft engine based on a flexible optical fiber bundle provided by the present invention has the capability of three-dimensional high-speed imaging, high measurement stability and long working life, and can be applied to the field of experimental testing; it can perform three-dimensional high-speed acquisition of the radiation signal of the flame inside the combustion chamber of an aircraft engine at low cost and low complexity. At the same time, the endoscope adopts a heat-insulating and vibration-resistant structure, which can work stably for a long time in the combustion chamber of an aircraft engine, significantly improving its service life.

[0036] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0037] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle, characterized in that: include: a high-speed camera, a set of flexible fiber optic bundles, and multiple high-temperature endoscopes; The flexible optical fiber bundle is composed of a mother optical fiber at one end and a plurality of sub-optical fibers at the other end; the plurality of sub-optical fibers are connected to a plurality of high-temperature resistant endoscopes in a one-to-one correspondence; the plurality of high-temperature resistant endoscopes are evenly arranged around the combustion chamber to be measured and inserted into the combustion chamber; The high-speed camera is used to collect the mother optical fiber signal.

2. A three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle as claimed in claim 1, characterized in that: The high temperature resistant endoscope comprises: a sapphire window, a front end lens, a front end lens barrel, a rear end objective lens, a rear end lens barrel and a cooling jacket; Wherein, the sapphire window and the front lens are sequentially installed on one side of the front lens barrel; the front lens is installed in the front lens barrel, and the installation position is adjusted in the front lens barrel according to the field of view angle requirement; The front end lens barrel is composed of a metal shell and internal heat insulation materials, which wrap the internal optical elements; the cooling jacket completely wraps the outer periphery of the front end lens barrel; The rear end lens barrel is connected to the front end lens barrel by threads, and the rear end lens barrel is composed of a metal shell and internal heat insulation material; The rear end lens is installed inside the rear end lens barrel, and its position inside the rear end lens barrel is adjusted according to the position of the front end lens; The sub-fiber of the flexible fiber bundle is connected to the rear end lens barrel through a thread, and transmits the optical signal of the combustion chamber to the mother fiber of the flexible fiber bundle.

3. A three-dimensional high-speed measurement system for an aircraft engine combustion chamber based on a flexible optical fiber bundle as claimed in claim 2, characterized in that: The front end lens is a wide-angle lens.

4. The three-dimensional high-speed measurement system of an aircraft engine combustion chamber based on a flexible optical fiber bundle as claimed in claim 2, characterized in that: The cooling jacket has cooling air and cooling water channels inside.

5. The three-dimensional high-speed measurement system of an aircraft engine combustion chamber based on a flexible optical fiber bundle as claimed in claim 2, characterized in that: The rear end lens is a telephoto lens.

6. The three-dimensional high-speed measurement system of an aircraft engine combustion chamber based on a flexible optical fiber bundle as claimed in claim 2, characterized in that: The optical axes of the front lens and the rear lens are consistent.

7. The three-dimensional high-speed measurement system of an aircraft engine combustion chamber based on a flexible optical fiber bundle according to claim 1, characterized in that: The high-speed camera is used to collect the mother optical fiber signal and obtain the three-dimensional flow field characteristics inside the combustion chamber in combination with a three-dimensional tomography algorithm.

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