Temperature Field Study Based On Spectral Temperature And Image Grey Distribution Combined Technology

In the field of high temperature measurement,the measurement of flame temperature is an important target.Traditional contact temperature measurement methods have a slow response time and unsatisfactory temporal and spatial resolution,making it difficult to obtain both the temperature evolution of an object over time and the distribution of the temperature field.In contrast,non-contact spectroscopic temperature measurement methods can obtain spectral information and invert the temperature regardless of distance and external interference.Based on the one-to-one correspondence between the temperature distribution of an object and the spatial distribution of its radiated energy,an improved spectroscopic temperature measurement method is proposed and combined with grey-scale intensity images to obtain the distribution of the temperature field,solving the problem of missing spatial information in traditional radiometric temperature measurement and reconstructing the temperature distribution of the object to be measured.Based on the Planck blackbody radiation formula,this thesis establishes a radiometric spectroscopic temperature measurement model for multivariate pyrotechnics and pyrotechnic particles,and proposes a computational method to invert the temperature distribution.A set of simultaneous spectral-image acquisition equipment is established to detect the pyrotechnic agent,a thin molybdenum metal plate under the action of a Gaussian heat source,and a three-dimensional candle combustion field respectively to obtain spectral data and grey-scale images.In the data processing,a method is proposed to reduce the influence of the line spectra on the temperature inversion of the multifaceted pyrotechnic combustion by using the Wien transform of the combustion spectra to address the problem of underfitting and overfitting in the polynomial fitting of the pyrotechnic thermal radiation spectra,and then obtain their temperatures.The temperature inversion is performed on the thermal radiation spectrum of a thin molybdenum metal plate and combined with a greyscale intensity value image to obtain a two-dimensional temperature field distribution for the plate by matching the average grey-scale value of the corresponding acquisition area to the grey-scale value of the entire temperature field.For the candle burning flame,the cumulative superposition effect of its 3D burning image is eliminated and the 3D candle burning field is reconstructed on the 2D COMS target surface by projecting the grey scale image and carrying out the candle burning field temperature inversion to obtain the central slice laminar distribution of the 3D temperature field.This thesis not only provides a new method for non-contact temperature measurement,but also provides implications for 3D temperature field measurement and reconstruction.