Research On The Influnce Of Hencken Flame Structure To FS-CARS Spectre Temperture Calibration

Combustion is the main source of energy in the world today, temperature is the most important parameters in the combustion field, there is an important practical significance obtaining temperature information accurately and quickly, which can provide the important reference for establishing an effective combustion model,understanding the physical and chemical process of combustion deeply and improving the existing combustion system. The combustion temperature measurements include contact measurement methods, such as thermocouple and non-contact measurement means such as CARS. For contact measurement, it is lilmited by environmental conditions and not suitable for high temperature measurement; and for non-contact laser spectrum measurements, it is not limited by environmental conditions and can realize accurate measurement relatively in the field of high temperature, which has high time and spatial resolution. This topic researches femtosecond pulse CARS spectroscopy,which is a kind of contactless temperature measurement and studies Hencken flame structure on the influence of the temperature calibration process.At first Hencken type burner and the CARS spectra technology research status are introduced; the propane/air diffusion flame characteristic are researched qualitatively;And temperature distribution law of the axial and different cross section was studied by thermocouple temperature measurement method, which purpose is to find the area which is accord with the theoretical calculation temperature; Second, one dimensional temperature distribution of combustion of Hencken burner was studied by means of temperature measurement of femtosecond of single pulse CPP- CARS spectroscopy,and analyzes its the temperature error of different measuring point temperature with the fitting of femtosecond CARS.According to research idea above, according with the experiment required I design Hencken flat flame burner, set the S type thermocouple temperature measuring device,and study the influence law of temperature distribution of the different equivalent ratio,average flow velocity and oxygen concentration. Experimental results show that the flame is nearly four sprayed, flame height and burning depends mainly on fuel flow rate,and when the equivalent ratio is 0.471, with the increase of axial height, measuring point temperature wave as a nearly sinusoidal and then gradually decrease, the average of the cooling rate is 0.5℃/mm, the average temperature of axial direction of all points is 1131℃, which is 1.4% lower than the theoretical calculation temperature; As methane flow rate increases, the axial temperature increases gradually with height and then appear the phenomenon of lower; When oxygen concentration was 21%, within the scope of the measure, the axial temperature has no change generally with the increase of height.At the same time, we set up a femtosecond monopulse CARS experiment device based on chirp pulse spectrum, adjusting three laser light path and the delay time, get a stable CARS signal, then detect high temperature flame of Hencken flat flame burner.The experimental results show that the temperature of one dimensional distribution of flame is between 1350 k and 1450 k by femtosecond CPP-CARS spectroscopy, and compared with thermocouple measurement results, it can be seen from one side to the other that flame temperature presents a trend of decrease at first then increase, the highest temperature is in the center of the fire; In addition to the temperature,the optimal model parameters is only Chirp Aprobe values,fitting errors are mainly concentrated in the vicinity of 0.01 and 0.02.