【作者】 马伟；

【导师】 宣益民；

【作者基本信息】 南京理工大学 ， 工程热物理， 2011， 博士

【摘要】 随着现代科学技术的迅猛发展,卫星热辐射特性的研究在航天技术、通信导航以及目标探测等领域的应用价值日益凸显。热控涂层是卫星表面的第一道防护屏障,在高能带电粒子、紫外、原子氧等恶劣的空间辐照环境作用下,热控涂层的光学性能发生退化,改变了卫星的热辐射特性,为空间目标的红外隐身与识别工作带来了一系列的干扰因素,研究空间环境效应对热控涂层性能退化的影响有着十分重要的意义。本文以卫星热辐射特性为主体研究框架,建立了一套完整的用于研究卫星热辐射特性的模型方法,特别地对空间辐照环境效应对热控涂层的退化机理展开了深入的研究,给出热控涂层性能退化的预测模型,分析了热控涂层性能退化对卫星热辐射特性的影响,主要工作包括：1.卫星热辐射特性的理论建模考虑空间轨道外热流、卫星结构、热控方式、内部载荷等因素的影响,建立了卫星温度场和红外辐射特性计算模型,给出了几种典型热控方式的数值计算模型,利用有限容积法计算得到了卫星的温度场和红外辐射通量分布,采用系统灵敏度理论分析相关参数变化对卫星热辐射特性的影响。考虑探测器视场内点源目标的成像特性,建立了空间点源目标的红外成像模型,生成了卫星在周向方向上的点源辐照强度分布。考虑地球-大气背景的红外传输特性,计算得到不同波段下的地球-大气背景的红外辐照通量分布。2.热控涂层对太阳辐射吸收性能退化预测模型分析了卫星在轨运行时所面临的复杂的空间辐照环境,提出热控涂层太阳辐射吸收性能在空间辐照环境下的退化预测模型。结合国内外公开发表的试验数据,采用最优化约束性算法,给出了几种常用热控涂层光学性能退化的预示表达式。通过误差理论对所提出的预测模型的计算精度进行讨论,并预测几种常用热控涂层在空间环境下的退化结果。3.热控涂层光谱性能退化特性的理论建模对热控涂层物理结构与能量吸收机理进行了研究,找出了影响热控涂层光谱吸收性能的各种因素,分析了各种影响因素在空间辐照环境下参数退化的概率模型。以Mie氏散射理论和等效介质理论为基础,研究了入射能量在多层非均匀折射率半透明介质涂层中的传递机理,建立了热控涂层在空间辐照条件下表面光谱吸收性能退化的计算模型,预测了高轨带电粒子和低轨原子氧环境下热控涂层光谱吸收性能的退化结果。4.卫星热辐射特性仿真计算集成软件的开发基于WINDOWS操作系统,利用软件工程的原理和方法设计开发了一套卫星热辐射特性的仿真计算应用软件,提供了完整的以人造地球卫星为典型代表的卫星温度和红外辐射特性计算仿真功能,并可以分析热控涂层在空间辐照环境下的性能退化以及对卫星热辐射特性的影响。采用MFC可视化程序设计语言开发了软件操作界面,在操作界面中可以完成卫星计算参数的输入以及相关功能的设定。采用OPENGL图形库进行计算数据的分析,并完成目标与背景的红外热场景渲染等后处理功能。更多还原

【Abstract】 Research on thermal radiation characteristics of satellite has valuable applications in space technique, communications, navigates and targets detection. As the first protective barrier on the surface of satellite, thermal control coating is vital for the reliable operation of spacecrafts in orbit. However, the rigorous environment in space will exert the harsh effect on the spectral feature of thermal control coatings of spacecrafts. The coatings may be subjected to bombardment of ultra-fine particles and undesired radiation in the outer space. Protons, electrons, atomic oxygen, and ultraviolet radiation in space will induce performance degradation of the coatings on spacecrafts. It changes the thermal radiation characteristics of satellite and brings some unfavorable factors for the infrared stealth and target identification work of satellite. It’s much important to further investigate on the degradation performance of thermal control coating exposured in space radiation.As thermal radiation characteristics of satellite to be the main research framework, a numerical model used to study the thermal radiation characteristics was proposed based on the computational simulation method. Especially, the environmental effects of space radiation on the degradation of thermal control coatings were carried out. Predicting model for the degradation of spectral properties of the coatings was established. Furthermore, some analysis on the variation behaviors of thermal radiation characteristics induced by the degradation of thermal control coating was carried out. The main work of this paper includes:1. Modeling research for thermal radiation characteristics of satelliteConsidering the influences of heat flux of space orbit, thermal control modes and heat load, temperature and infrared models of satellite were developed. The numerical models for some typical thermal control suites were proposed. The distributions of both temperature and radiation of satellites were obtained by finite volume method. Sensitivity affected by temperature-dependent parameters such as thermal conductivity and heat capacity were discussed. Infrared imaging model of point source target drawing in the district of detector was established and the distributions of its radiation intensity were produced in circumferential direction. Take into account of radiation transmission characteristic of the backgrounds consisted of earth and atmosphere, the infrared images of the backgrounds were shown in different wavelengths regions.2. Degradation model of solar absorption by thermal control coatingThe rigorous space environment which the thermal control coatings exposed to was introduced and the degradation model of the solar absorption was proposed. Under the guidance of the experimental data both at home and abroad, the formulations which describe the variation of optical parameters of thermal control coatings were deduced by the least square method. The accuracy of the degradation model was verified and degradation behaviors of the absorption factor for some typical thermal control coatings were predicted.3. Modeling for degradation behaviors of spectral properties of thermal control coatingsBy studying the physical components and the energy absorption mechanism, the factors which determine the spectral properties of the coatings are founded. Mathematical expressions for the variations of the influence factors have been introduced for complicated environment. The transmission mechanism of energy incident into a non-uniform refractive index transparent media was deeply studied based on the Mie’s theory and Stratified Media theory. Based on these work, a predicting model for the degradation of spectral absorptance properties of the coatings is established. By using the theoretical model, degradation behaviors for both high orbit and low orbit was predicted which validated the above model gives a useful approach for predicting the degradation behaviors of thermal control coatings on spacecrafts in orbit.4. Development of integrated software for the thermal radiation analysis of satelliteBased on WINDOWS-operating system, integrated software for thermal radiation analysis of satellite (ISTRAS) was developed. It provides simulation functions as temperature distributions and infrared characteristic of the satellite. Moreover, it can be used for degradation behavior’s research of satellite exposured in space radiation. The software’s interface was compiled using MFC visual programming language, one can completed inputs and settings of parameters and related functions in the user’s surface. OPENGL graphics library was used to generate the three-dimensional infrared thermal imaging results of target and background.更多还原