Supersonic combustion instantaneous flame structure high time-space resolution visualization system

Abstract

The invention provides a supersonic combustion instantaneous flame structure high time-space resolution visualization system. The supersonic combustion instantaneous flame structure high time-space resolution visualization system comprises a laser unit, a supersonic combustion chamber and a data acquisition unit. The laser unit is used for generating laser, shaping the laser into a laser light sheet and then conducting the laser light sheet into the supersonic combustion chamber; the supersonic combustion chamber is provided with a laser incidence window and a data acquisition window, the laser light sheet is incident into the supersonic combustion chamber through the laser incidence window, hydrocarbon components generated in the combustion process are subjected to photolysis, CH photolysis fluorescence is generated, high-temporal-spatial-resolution imaging is conducted on the photolysis fluorescence through the ICCD camera, and high time-space resolution visualization of the supersonic combustion instantaneous flame structure is realized. A complex dye laser is not needed, wavelength tuning is not needed, and the laser is simple and portable in structure and convenient to maintain and use.

Description

technical field [0001] The invention belongs to the technical field of supersonic combustion, and in particular relates to a supersonic combustion instantaneous flame structure visualization system with high temporal and spatial resolution. Background technique [0002] Achieving high-efficiency, low-resistance and stable combustion in supersonic airflow is a key factor for optimizing the thrust performance of a scramjet. The mechanism of supersonic combustion phenomenon is complex. Studying the flame structure of supersonic combustion will help to reveal the mechanism of supersonic combustion and provide support for optimizing the design of scramjet combustion chamber. However, the flame structure is easily disturbed by complex factors such as turbulent vortex structure, shock wave, and boundary layer during tissue combustion in supersonic airflow. There is an urgent need to develop methods for visualizing supersonic combustion flame structures. [0003] At present, the c...

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Problems solved by technology

[0005] (1) The flame structure captured by high-speed photography is the result of path integration in space, and because the flame spontaneous radiation is weak, a longer exposure time (~μs level) is required to increase the intensity of the flame spontaneous emission light signal. The image of the time is the result of the accumulation of a large exposure time, so the temporal and spatial resolution of the high-speed photography method is poor, and it is impossible to realize the high temporal and spatial resolution visualization of the instantaneous structure of the flame

[0006] (2) Planar laser-induced fluorescence (PLIF) can obtain instantaneous flame structures with high spatiotemporal resolution by imaging the two-dimensional distribution of free radicals such as CH and OH, but usually requires the use of wavelength-tunable dye lasers. The PLIF signal can only be generated when the energy level transition wavelength corresponding to free radicals such as , OH, etc., so the PLIF technology system is more complicated, and it is more difficult to maintain and use

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