The Development Of The Flame Dynamics Experimental Measurements System Based On Chemiluminescence

Various level of free radical step in the process of combustion will generate chemiluminescence,and the information of flame chemiluminescence is closely linked to parameters including flame temperature,concentration of groups,and heat release.As flame chemiluminescence contains abundant information,the study does an in-depth research on kinetics of flame based on the characteristics of flame chemiluminescence to understand the combustion characteristic and increase the understanding of combustion.This study uses the spontaneous chemiluminescence of flame CH~*and OH~*as gripper to set up three sets of experimental system that is used for researching flame dynamics.In flame transfer function measure system,optical fiber is used to directly obtain the whole chemiluminescence of flame to indicate heat release rate,which is applied to study flame transfer function;In the flame chemiluminescence continuous dynamic acquisition system,Cassegrain optics is used to capture the chemiluminescence of fixed-point,which can realize the acquisition of continuous dynamic intensity signals of chemiluminescence to study the flame front structure;In flame chemiluminescence image acquisition system,filter and ICCD camera are used to obtain the flame chemiluminescence in a two-dimension plane,which can proceed the tomographic reconstruction of chemiluminescence image for the study of flame structure analysis and dynamic changes.Results are specified as following:(1)Flame transfer function measurement system establishmentThe study introduces an overall designed plan on the flame transfer function measurement system,which includes experimental data processing software based on LabVIEW.In order to overcome the inherent frequency in sound field under the action of combustion system and to eliminate the effect of the distortion of flame transfer function of data processing caused by LabVIEW waveform measurement module limitations,unilateral Fourier transform programming was implemented to obtain the accurate flame transfer function data.Compared with the data from manual calculation,the accuracy of measurement system is verified.(2)Establishment and accomplishment of continuous dynamic sampling measure system based on cassegrain opticsThe hardware and software of continuous dynamic sampling measure system on flame chemiluminescence is established.The sampling mode is chose after discussion,and the analysis of accuracy was made with the experiment results.The dynamic resolution of flame measurement is calculated on a micron level.In that way,detailed information about flame front structure can be captured accurately,which is useful for quantitative analysis of flame front thickness.The thought--Full Width at Half Maximum(FWHM)is applied to quantitatively analyze flame front and to design calibration experiment(apdot half maximum in FWHM as 0.8).By comparing the data from quantitative analysis on flame front with the data from previous experiment,the accuracy of data can be verified.(3)The establishment of flame chemiluminescence image acquisition systemHardware system is established to obtain the flame chemiluminescence image,by applying filter and ICCD camera model.The tomographic reconstruction programming is coded,and inverse Abel transform based on Fourier series expansion is applied on flame chemiluminescence image to obtain high spatial resolution tomograhic image.The study uses the thought of FWHM acquire flame front thickness,and uses flame front thickness as the anchor to analyze the accuracy of tomographic image that is obtained from inverse Abel transform.Camparing with data obtained from previous quantitative analysis of flame front,the number of series expansion of tomographic image obtained from inverse Abel transform based on Fourier series expanis is 75,and accuracy analysis is verified.