Research On Environmental Simulation Test Technology And Experimental Verification Of Three-dimensional Temperature Field Of High Temperature Fireball

In view of the extremely harsh environment such as high temperature,high pressure,high speed and high impact,the formation of fireball at the explosion site is too short and it is difficult to accurately measure the transient high temperature of high-temperature fireball,a hightemperature fireball quasi-static simulation device is designed in this paper,which uses the simulation device to generate a stable high-temperature fireball in the laboratory environment,so as to solve the problem that the measured data in the actual explosion field is not enough to clearly understand the fluid situation and temperature distribution in the fireball.According to the current situation that the multi physical field characteristics inside the high-temperature fireball in the actual explosion field cannot be accurately measured,in order to study the internal fluid characteristics of the high-temperature fireball formed by the multi pipeline injection technology under different control parameters,this paper numerically simulated the environment under the multi pipeline injection technology during the experiment,and analyzed the heat transfer information inside the simulation device,and an experimental method for simulating the intrinsic fluid characteristics of the actual explosion fireball was explored,which provided a feasible environmental simulation device and method for the field transient high temperature test.In order to generate a stable fireball,the designed simulation device used Raspberry Pi 3B as the main controller,used multi pipeline injection technology to inject high-temperature gas,and automatically controlled the state of three groups of spray guns through artificial theoretical calculation,simulation and designed multi physical field parameters,so as to realize the automatic regulation of simulated fireball multi physical field and form a three-dimensional high-temperature flame area that meets the experimental requirements.According to the internal temperature range,element concentration and fluid characteristics of high-temperature fireball in the actual explosion field,the stability control method of high-temperature fireball was explored,and the structural design of simulated high-temperature fireball meeting the requirements of multiple physical characteristics was constructed and optimized.The deflagration process of fireball is too short,so it is difficult to measure the information of fireball accurately.In order to solve this problem,based on the overall working environment of the high-temperature fireball quasi-static simulation device experiment,Zhang Zhengyou calibration method was used to calibrate the internal and external parameters of the camera,so as to realize the view visualization of the device and flame.In order to verify the correctness of the simulated temperature,the elements in the deflagration were sampled and analyzed by laser induced breakdown spectroscopy.The characteristic elements were selected for spectral emissivity calibration experiment and the filters were equipped for flame image acquisition and analysis.The temperature of the flame of the high-temperature fireball quasi-static simulation device experiment was measured by an infrared thermal imager and compared with the simulation results.The results show that the k-ε turbulence model and the solution of heat of formation of chemical reaction can well reproduce the combustion of the actual high temperature fireball.The simulation method can provide quantitative values for visual data,calibration coefficient and measured temperature.