Research On Testing Technology Of Temperature Field Of Micro-Pyrotechnics

The temperature field test of the pyrotechnic device is one of the detonation flow field tests of the pyrotechnic device,which can reflect the combustion characteristics,ignition characteristics and the pros and cons of the design of the energy converter of the pyrotechnic product.This topic studies the detonation flow field characteristics of pyrotechnics and the schlieren optical diagnosis technology for visualizing uneven flow fields.The research is carried out from the three aspects of combustion characteristics,optical diagnosis technology and detonation flow field testing of pyrotechnics.By introducing the theory of combustion characteristics,define the flow field type of pyrotechnics ignition,and verify it through the schlieren optics test experiment of pyrotechnics.According to the combustion characteristics,the combustion type is divided into premixed combustion and non-premixed combustion,and the flow field type is divided into laminar flow,turbulent flow and transitional fluid.Use the pyrotechnics test experimental device to test the detonation flow field of the pyrotechnics,collect the schlieren image of the ignition flow field of the pyrotechnics by a high-speed camera,and analyze and discuss the schlieren sequence diagram.Based on the optical diagnosis technology,the schlieren optical system is used for simulation algorithm research,and the experiment of the schlieren test system is carried out.For the optical diagnosis of transparent flow field objects,the schlieren diagnosis technology,shadow diagnosis technique and background schlieren diagnosis technique are introduced respectively,and the advantages and disadvantages of each diagnosis technique are analyzed,and the schlieren diagnosis technique is selected as the research method for the flow field test of initiating explosives..By defining the illumination optics,flow optics and imaging optics in the schlieren simulation system,the computer is used to simulate the entire optical system to obtain schlieren imaging results with different system component parameters.The degree of visualization of the light field intensity of the simulation research object on the imaging surface depends on the wavelength of the light source,the refractive index of the test object,the diameter of the test object,and the position of the knife-edge cutting light field spectrum surface.Compared with the simulation research,the schlieren verification experiment of the symmetrical flow field is carried out,and the experimental results obtained are consistent with the simulation results.Using the schlieren optical experimental system and the pyrotechnics ignition device,the detonation flow field of the pyrotechnics was tested,and the time series schlieren image containing the temperature field parameters of the pyrotechnics was obtained,and the temperature field test technology research was completed.Based on the physical quantity relationship of the temperature field,the geometric theory of light refraction and the schlieren test theory,the temperature field test model of the pyrotechnic device is obtained,which is used as the theoretical basis for solving the time series temperature field of the pyrotechnic device.In the test experiment of pyrotechnics,the obtained time series schlieren images were studied on the propagation characteristics of hot gas and bridge fragments,and the time series temperature test results of the flow field of pyrotechnics were obtained.The research results show that the schlieren optical system is not only suitable for large-scale high-speed imaging tests such as large field of view,wind tunnels,explosions and shock waves,but also for testing transparent objects with small refractive index changes.The combination of schlieren technology and high-speed digital imaging technology can obtain data sets of a variety of test objects,so as to conduct multi-dimensional space-time correlation research.Through this method,unstable,transitional and turbulent flow fields(such as fire Detonation flow field of work product)to provide a reference for transient diagnosis.