| According to the blackbody radiation law, all physical objects above absolute zero temperature will radiate electromagnetic wave energy. Information of objects could be got by analyzing these electromagnetic waves, which is the base of passive detection technology. Therefore, the study on the characteristics of these emitted millimeter-waves is the basis for object radiation detection. Currently, the research on millimeter-wave radiation of object is mostly concentrated on low-temperature radiator(the temperature of the object and the ambient temperature are nearly the same), however, little study has been done on solid rocket motor plume on millimeter band, and despite many researches have been done on the infrared, ultraviolet band. Therefore, the study on millimeter radiation mechanism and radiation characteristics of the solid rocket plume has an important significance in the detection of solid rocket motor plume.As the first part of the paper, the spectrum characteristics of the combustion product in rocket plume has been calculated from the point of molecule spectral line, based on formation mechanism and combustion characteristics. Based on the result, the hierarchical model of temperature has been simulated in FLUENT, and concentration model of products has been established based on the combustion characteristics of plume. Combined with the spectral lines of plume components, the brightness temperature of plume has been simulated. By analyzing the results, we came to the conclusion that Al2O3 has showed its great contribution in plume's brightness temperature.Secondly, great mass fraction is also a point to the unignored contribution of Al2O3 to the plume radiation. Since Al2O3 mainly exists in the form of solid particles in the plume. The scattering characteristics of Al2O3 particles from the perspective of particle scattering has been studied. Then, combined with hierarchical model we calculate the contribution to the plume radiation. With all the above simulation results, we eventually got the millimeter-wave radiation characteristics of the solid rocket motor plume.Finally, we launched the measuring experiment of the millimeter-wave radiation of the plume, according to simulation requirements. The correctness of the study of the millimeter-wave radiation of plume has been validated by comparing the experiment result and the calculation result, which provide theoretical and experimental basis for the solid rocket exhaust plume radiation detection on the millimeter-wave band. |
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