Temperature measuring method based on carbon monoxide femtosecond laser induced fluorescence spectrum technology

Abstract

The invention discloses a temperature measuring method based on a carbon monoxide femtosecond laser induced fluorescence spectrum technology. The temperature measuring method comprises the steps of: generating femtosecond laser with a first central wavelength by using a femtosecond laser device, wherein the femtosecond laser is tuned to a second central wavelength after passing through a frequencydoubling crystal, the femtosecond laser with the second central wavelength is focused in a combustion field to be detected generated by a combustor after passing through a focusing lens, and excitesCO molecules in the combustion field to be detected to undergo resonance transition, so that the CO is excited to a high energy level; and transitioning the CO at the high energy level to a low energylevel, releasing a CO fluorescence signal having two sets of vibration and rotation spectrum bands, performing beam splitting on the CO fluorescence signal by means of a spectrograph, collecting CO fluorescence spectral signals by means of an ICCD camera and transmitting the CO fluorescence spectral signals to a computer, and analyzing the fluorescence spectrum by using the computer so as to obtain temperature information of the combustion field. The temperature measuring method is an optical measuring method, has a simple measuring system, has little interference on a flow field to be measured, and can realize the real-time online measurement of temperature in closed and open combustion fields.

Description

technical field [0001] The invention relates to the technical field of femtosecond laser diagnosis, in particular to a temperature measurement method based on carbon monoxide femtosecond laser-induced fluorescence spectroscopy technology. Background technique [0002] Combustion temperature is an important parameter to characterize the combustion process. Obtaining accurate temperature information of the combustion field can not only provide technical support for explaining the formation of intermediate products in the combustion process, but also promote a further understanding of the flame propagation mechanism [ . [0003] However, the complexity of the combustion field makes temperature measurement challenging. Because the traditional contact temperature measurement method will cause serious interference to the flow field and combustion reaction, it is not suitable for application in the combustion field. Compared with this, the non-contact optical temperature measure...

AI Technical Summary

Problems solved by technology

The signal-to-noise ratio of CARS technology is good, but the spatial resolution is poor; Rayleigh scattering technology can measure the two-dimensional spatial distribution of combustion field temperature, but there are still some limitations under high pressure conditions and soot conditions

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