Heat Transfer Simulation Based On Finite Element Analysis And Blackbody Radiation Source Development

As the core technology of the earth observation system,infrared remote sensing technology is widely used in many fields such as meteorology,national defense,disaster prevention and reduction and environmental monitoring.And with the development towards the direction of high quantization,high spectral resolution and high position resolution,it has been put forward an urgent demand for the metrological traceability in the field of infrared remote sensing.Therefore,the research and development technology of blackbody radiation source needs to be constantly improved.As a standard source of which the internal temperature field is a uniform isothermal field,the blackbodies are used to calibrate various measuring instruments,which requires the temperature stability and the temperature field uniformity of the blackbodies to reach a relatively high level.Nevertheless,the temperature gradient of the inner temperature field of blackbodies results in the calibration accuracy of measurement equipment.Therefore,improving the temperature field uniformity of blackbodies,is a development difficulty and also of great practical significance in the calibration of measuring equipment.In this paper,based on the heat transfer simulation of vacuum blackbody and non-vacuum blackbody,the blackbody structure was optimized to improve the calibration accuracy,and the blackbody was tested experimentally to verify the rationality of the simulation results,and the temperature field of the blackbody was investigated mainly.The main contents of this paper are as follows:Firstly,the development status of blackbodies is sorted out by referring to relevant materials.The existing problems in the development process of blackbodies and the bottlenecks in controlling the uniformity of blackbodies temperature field are put forward,and the significance of this paper is briefly described.After understanding the requirements of its technical indicators,a threedimensional model,of which the mesh was divided reasonably and the boundary conditions and loads were determined was created.The software was used to analyze the blackbody heat transfer mechanism and temperature field uniformity.By analyzing the simulation results and adjusting the corresponding parameters,the optimal results are obtained.The structure and the temperature control system of the blackbody was designed,which including the cavity structure of the blackbody,the heating and cooling mode,temperature sensor selection and installation,interface and insulation and other key parts.In the temperature control part,the variable power supply module was used to provide power for blackbody,and fuzzy PID was used to adjust the temperature,so that the working temperature of blackbody radiation source could reach the set temperature precisely.Finally,the blackbody was tested and compared with the simulation results to verify the accuracy and reliability of the simulation results.The development cycle and cost of the blackbody are greatly reduced,and the temperature uniformity of blackbody is improved to meet the requirements of technical indexes through the heat transfer simulation of blackbody radiation source temperature field.The accuracy of the simulation is verified by the experimental results,and the feasibility of the thermal simulation method in the development of the blackbody is also demonstrated.The researches of this paper are of certain reference value to the development of the blackbody for the future,and also to the calibration of temperature field uniformity and temperature measuring equipment in the future.