Research On Detection,Reconstruction Method And Experimental Technology Of Temperature Field Based On Element Self-excited Radiation Energy Spectrum

For the research needs of military and industrial areas about temperature field detection,reconstruction and visualization under extreme environment.In this paper,a temperature field modeling,detection and reconstruction method based on the mechanism of element self-excited radiation energy spectrum is proposed.The element doping method and filament emission spectrum method are respectively used to explore the two-dimensional spectral characteristic and temperature distribution of the surface and internal section of high temperature flame.High-precision s CMOS scientific camera was used as the main equipment for temperature information detection,and common industrial camera was used as the topography information detection equipment.A high-temperature field ring array projection detection system was constructed,the optimal distribution pattern of the detection array was evaluated,and the synchronization of multiple detection modules was designed.Taking the high temperature flame as the detection object,the three-dimensional reconstruction result of its space surface shows that the relative error of volume reconstruction is better than 8%.Laser-induced breakdown spectroscopy(LIBS)was used to analyze the combustion residue of high temperature source material,to select the intrinsic characteristic elements and wavelength of characteristic energy spectrum.Combined with the calibration principle of detection module,the forward thermal-optical-electrical coupling radiation transfer model was established,and the filter projection detection module was designed.Results show that Al,Ca,Mg,Na,K and other elements are widely exists in energetic materials and biomass fuel and have strong excitation spectrum characteristics in the vicinity of specific wavelength(Al 395 nm,Ca 422.67 nm,Mg 518 nm,Na 589 nm,K 768nm).Finally,we choose K element as external doping element.Results verified the feasibility of narrow band temperature field measurement based on the excitation of doping element.Oxygen-ethanol premix flame was taken as the test object,spectral emissivity calibration experiment of materials was designed according to the element spectral excitation model.The experimental scheme of temperature and spectral emissivity distribution measurement based on element doping method and its verification were given.The relative error of temperature measurement is less than 5%.According to the specific spectral emission characteristics of graphite fiber filaments,a temperature measurement experiment based on filament emission spectrum was designed,and the relative error of temperature measurement was less than 6%.The experiment was carried out with multi-line ejection of oxygen-acetylene high temperature fireball,results show that the temperature field detection and reconstruction method based on the element self-excited radiation energy spectrum can effectively realize the high temperature field measurement.