Reconstruction Of Three-Dimensional Flame Temperature Field Using Light Field Camera

The phenomenon of combustion widely exists in the production and life fields of metallurgy,aerospace,thermal power generation,etc.,and the temperature is one of the most important combustion flame parameters.Accurating measurement of the flame temperature field can better reveal the essence and law of combustion,thereby improving energy efficiency and ensuring safety and reducing pollution.The current flame three-dimensional temperature field measurement method has the problems of complex equipment and high time delay.In order to solve these problems,a method to reconstruct the three-dimensional flame temperature field based on the light field camera is proposed,and theoretical and experimental research is carried out in this paper.The concept and parametric characterization of light field are introduced and the principle of digital refocusing of light field imaging,as well as the basic principles of optical imaging and layered imaging are studied.The optical field image decoding and refocusing program are realized,and the refocusing technology of the optical field camera is applied to the optical layered imaging system.The calibration of layered imaging system based on optical field camera is carried out,and the calibration principle and method are studied.The method of focusing parameter calibration based on step ruler is proposed,which improves the accuracy and ease of calibration,and realizes the calibration of focusing parameter and corresponding depth distance.In the process of layered imaging reconstruction,the point spread function is also needed.In this paper,the gaussian point spread model and the edge method is used to calibrate the point spread function parameters.The reconstruction algorithm for optical stratification imaging is studied,the two algorithms are simulated and compared,and the nearest neighbor method is used to carry out the layered reconstruction experiment.The calibration experiment of blackbody furnace based on double color method was carried out before temperature measurement.The experiment of three-dimensional temperature field reconstruction based on the light field camera is carried out.The flame is collected by the light field camera and divided into three fault planes.The original brightness distribution and temperature field of the three layers are reconstructed based on the previous work.The results are analyzed and evaluated.The reconstructed flame temperature field basically conforms to the structural characteristics of the combustion flame.The results show that the temperature measurement method is feasible and reliable.It can be used to measure the three-dimensional flame temperature field.