Research on Pyrophoric Multi-Hole Activated Metal Spectral Radiation Characteristics
HUANG He-song1, TONG Zhong-xiang1, CHAI Shi-jie1*, MA Bang2, WANG Chao-zhe1
1. Aeronautics and Astronautics Engineering College, Air Force Engineering University, Xi’an 710038, China
2. 8511 Institution, China Aerospace Science and Industrial Corporation, Nanjing 210007, China
Abstract：The contact area between multi-hole activated metal and air greatly increases, because of the large number of holes in multi-hole activated metal. So the combustion of multi-hole activated metal is serious in the air, which causes the temperature rising rapidly. The combustion process is quite complex and belongs to solid combustion. To solve the combustion problem of multi-hole activated metal, magnesium was chosen as the activated metal in the paper. The combustion models were established to research the spectral radiation characteristics. Firstly, we established the relationship between total consumption of oxygen and residual mass of activated metal and studied the diffusion concentration of oxygen in activated metal hole. The relationship between temperature and time were obtained by solving the heat balance equations of active metal in the process of combustion. Secondly, the simulation results by calculation were compared with the experiment results which were obtained by thermal imager. The results demonstrated that the model calculated results consistent with experiment and the error was controlled within 10%. Finally, the burning rule and spectral radiation characteristics of activated metal were studied by the establishment of combustion models. So the problem that the spectral radiation intensity is difficult to be obtained by experiment at high altitude and velocity was solved, which decreased the experiment cost and time. The activated metal radiation intensity in the waveband of 1～3, 3～5 and 8～12 μm were compared at different time and get the condusion that the nain radiation intensity focuses on the waveband of 3～5 μm. The results demonstrated that: the maximal burning temperature increased firstly and then decreased with the increase of the velocity . It also decreased with the increase of the altitude; The temperature reached maximum at the speed of 30 m·s-1; Activated metal spectral radiation intensity reached maximum at the waveband between 2 to 6 μm. The models can be applied in studying other activated metal burning characteristics.
