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刘宇明%冯伟泉%丁义刚%郑慧奇%赵雪 《宇航材料工艺》2007,37(4):61-64
研究了SR107-ZK在紫外辐照、质子辐照和综合辐照环境下太阳吸收率αs的退化情况,利用XPS和SEM对样品表面的成分和形貌进行了分析.结果表明:SR107-ZK的αs受紫外辐照影响较小,但是在质子和综合辐照条件下,αs退化明显.紫外辐照会对SR107-ZK的硅橡胶黏合剂产生裂解作用,这种作用在带电粒子的协同辐照下更加明显. 相似文献
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为了研究深空辐射环境对SCB-1型空间高吸收率消杂光涂层的太阳光谱吸收性能影响。采用5 000 ESH剂量的真空-紫外、2.5×1015 p/cm2注量的真空-质子和2.5×1016 e/cm2注量的真空-电子依次对SCB-1消杂光涂层进行串联辐照试验,分析各项辐照试验前后消杂光涂层外观、太阳吸收比αs及半球发射率εH的变化情况。并采用热失重分析(Thermal Gravity Analysis)判断消杂光涂层受辐照试验后的分解情况与热稳定性变化。经串联辐照试验后,SCB-1消杂光涂层全波段太阳吸收比总变化值Δαs下降了0.011~0.012,400~1 100 nm波段太阳吸收比总变化值Δαs下降了0.011~0.013,以上三项串联辐照过程中SCB-1消杂光涂层的半球发射率总变化值ΔεH无明显变化。SCB-1消杂光涂层呈现了极佳的深空辐射环境下的消杂光持久性,可对未来深空探测领域的光学技术发展提供有力支持。 相似文献
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卫星在轨运行期间,热控涂层要经受空间复杂环境效应的影响,其光学和热控性能逐渐下降,影响卫星可靠性和寿命。本文利用卫星搭载技术,完成热控涂层5年的在轨试验,验证空间多因素环境对热控涂层的影响。同时,利用地面模拟试验装置,模拟空间质子、电子、紫外等5年的辐照剂量对热控涂层的作用。对在轨试验结果进行解读和分析,并与地面模拟试验结果进行比对。结果显示,在搭载试验和地面试验前,热控涂层太阳吸收比(αs)为0.12,经5年在轨搭载试验后,αs退化为0.23。经地面模拟试验后,αs退化为0.22。搭载试验和地面试验的热控涂层性能均呈现线性退化规律,表明在确定的轨道环境和固定的剂量率条件下,热控涂层的退化与环境作用时间正相关,同时验证了地面试验的有效性。 相似文献
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《航空材料学报》2014,(1)
以有机硅树脂、聚碳硅烷和玻璃粉为黏结剂,添加Al2O3,BN,SiC,ZrO2,SiO2和碳纤维等耐热填料制备了抗烧蚀涂层,对其物理机械性能进行了表征,同时分别采用马氟炉、氧乙炔焰烧蚀对其耐热抗烧蚀性能进行了表征。研究结果表明:玻璃粉、BN对改善涂层裂纹起关键作用,ZrO2对提高涂层隔热和耐烧蚀性能至关重要。所研制涂层在厚度为1mm的30CrMnSiA钢基材表面涂覆600μm,经受3000℃氧乙炔焰4s烧蚀,钢基材不发生穿孔;900μm厚度的涂层在531W/cm2激光功率密度下照射4s,带涂层钢基材背面温度比同等辐照温度下,空白钢板背面温度下降1000℃左右。 相似文献
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空间环境下的有机热控涂层 总被引:6,自引:3,他引:6
本文综述了国外在空间有机热控涂层领域中的研究工作和试验,着重分析了空间极端环境中紫外光辐照和原子氧侵蚀这两大因素对有机热控涂层的影响。 相似文献
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陈少华%张加迅%杨素君%邹永军%王敬宜 《宇航材料工艺》2005,35(4):33-36
以在我国某型号卫星上应用的两种有机热控涂层——改进型S781铝灰漆和S956灰漆作为对象,首次就近地轨道原子氧环境对涂层性能(太阳吸收比αS和红外半球发射率εH)的影响进行实验研究。实验中采用同轴源原子氧装置,以近地轨道原子氧通量条件对涂层进行试验。结果表明,原子氧对涂层表面的侵蚀作用是造成涂层性能退化的主要原因,在相同的原子氧剂量下,涂层性能变化的程度与涂层组成成分的配比有关。 相似文献
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派瑞林(Parylene)薄膜主要用于功率电刷的三防,确保电功率的稳定传输。本文对两种规格(17和27 μm)Parylene薄膜的厚度、热性能、绝缘性能、在铍青铜上的附着性能以及耐空间辐照性进行了研究。结果表明:通过真空气相沉积法制备的Parylene-C涂覆材料厚度误差可控在2 μm内;膜层在铍青铜上的附着力等级为1级,薄膜热分解温度为453 ℃,两种厚度薄膜击穿电压分别为3.65 kV(17 μm)和5.27 kV(27 μm);经2.5×1015 p/cm2质子辐照后,膜层外观均完好,附着性能、热性能、绝缘性能仍满足工程使用需求;经2.5×1016 e/cm2电子辐照后,膜层出现严重开裂、起皮现象。对电子辐照前后膜层的热性能、红外结构等进行了进一步的研究,分析了电子辐照后膜层的失效机理并获得了Parylene-C涂覆材料膜层耐空间电子辐照上限为1×1014 e/cm2。 相似文献
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研究了25 μm石墨膜在能量100 keV最大注量2.5×1015 p/cm2的真空质子辐照条件下的微观结构和热性能,采用拉曼光谱(Raman spectrum)、X射线衍射(XRD)、X射线光电子能谱(XPS)进行微观结构分析,采用激光闪射法(LFA)进行热性能分析。石墨膜晶面间距为0.335 83 nm,石墨化度为95.0%。结果发现,质子辐照会导致石墨膜表层产生缺陷,片层间距增大,石墨化度降低,氧含量升高;随着质子辐照注量的增加,Raman光谱中D和G峰的积分面积比表明缺陷密度不断增加。25 μm石墨膜经过能量为100 keV注量为2.5×1015 p/cm2质子辐照后,石墨膜热扩散系数无明显变化。 相似文献
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NING Guo-dong ZHANG Shu-guang FANG Zhen-ping 《中国航空学报》2007,20(1):1-8
A method for the implementation of integrated three-degree-of-freedom constrained entry guidance for reusable launch vehicle is presented. Given any feasible entry conditions, terminal area energy management interface conditions, and the reference trajectory generated onboard then, the method can generate a longitudinal guidance profile rapidly, featuring linear quadratic regular method and a proportional-integral-derivative tracking law with time-varying gains, which satisfies all the entry corridor constraints and meets the requirements with high precision. Afterwards, by utilizing special features of crossrange parameter, establishing bank-reversal corridor, and determining bank-reversals according to dynamically adjusted method, the algorithm enables the lateral entry guidance system to fly a wide range of missions and provides reliable and good performance in the presence of significant aerodynamic modeling uncertainty. Fast trajectory guidance profiles and simulations with a reusable launch vehicle model for various missions and aerodynamic uncertain-ties are presented to demonstrate the capacity and reliability of this method. 相似文献
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基于飞机油箱模型形状特征油量测量切片步长选择方法研究 总被引:1,自引:0,他引:1
在分析飞机数字式油量测量过程中目前广泛使用的切片法油量测量原理的基础上,针对现有的定步长切片法无法得到准确、可靠的燃油质量特性数据库的缺陷,结合对飞机油箱模型形状特征的分析,提出了基于飞机油箱模型形状特征的油量测量切片步长选择方法。此方法包括切片步长整体和局部选择两个过程,整体选择以实现相邻两切片平面所夹油箱模型体积近似相等为目的来确定切片步长,以体现油箱模型截面整体变化规律;局部选择以设计切片平面与截面突变平面重合或尽可能接近的方式,突出油箱截面的局部变化特征。实验结果表明:该切片步长选择方法较定步长方法能够建立更为合理、可靠的燃油质量特性数据库,从而提高了油量测量精度。 相似文献
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The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow 总被引:1,自引:0,他引:1
This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation. 相似文献
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Abnormal Shape Mould Winding 总被引:1,自引:0,他引:1
Fu Hongya Wang Xianfeng Han Zhenyu Fu Yunzhong 《中国航空学报》2007,20(6):552-558
为解决网格化芯模的缠绕问题,本文提出了复合材料面片缠绕机理;接着详细分析了面片缠绕过程中的芯模凹曲面上纤维滑线和架空现象,应用微分几何曲面理论和空间几何理论,提出判据及其解决方案;最后,针对飞机发动机进气道的缠绕成型,编制缠绕控制程序并进行相应的实验,验证了面片缠绕方法的可行性。 相似文献
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FU Hong-jun MA Chong-qi KUANG Nai-hang LUAN Shi-lin 《中国航空学报》2007,20(2):124-128
This work was dedicated to performing surface oxidation and coating treatments on carbon fibers (CF) and investigating the changes of fiber surface properties after these treatments, including surface composition, relative volume of functional groups, and sur- face topography with X-ray photoelectron spectroscopy (XPS) and atom force microscopy (AFM) technology. The results show that, after oxidation treatments, interfacial properties between CF and non-polar polyarylacetylene (PAA) resin are remarkably modified by removing weak surface layers and increasing fiber surface roughness. Coating treatment by high char phenolic resin solution after oxida- tion makes interface of CF/PAA composites to be upgraded and the interfacial properties further bettered. 相似文献
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Xu Chenghai Meng Songhe Zhang Mingfu Zuo Hongbo Wang Guigen 《中国航空学报》2007,20(5):475-480
本文利用有限元法对冷心放肩微量提拉法(SAPMAC)生长大尺寸蓝宝石单晶过程中的热应力进行了模拟计算,应用临界缺陷理论解释了裂纹的萌生与扩展机理。研究表明,晶体内的热应力主要与晶体生长速率,环境温度和结晶取向有关;较大热应力多出现在结晶界面,放肩、收尾以及直径急剧变化等位置;最大热应力总是出现在籽晶与新生晶体的界面附近。裂纹将在临界缺陷位置产生,并在应力作用下沿a或m面扩展。计算结果与实验结果基本吻合,通过晶体生长系统和生长工艺的改进,对晶体的开裂问题得到了有效的抑制。 相似文献
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CHENG Wen-yuan CHANG Yan CUI De-gang XIE Xiang-hui 《中国航空学报》2007,20(1):55-59
To solve the topology optimization of complicated multi-objective continuous/discrete design variables in aircmit structure design, a Parallel Pareto Genetic Algorithm (PPGA) is presented based on grid platform in this paper. In the algorithm, the commercial finite element analysis (FEA) software is integrated as the calculating tool for analyzing the objective functions and the filter of Pareto solution set based on weight information is introduced to deal with the relationships among all objectives. Grid technology is utilized in PPGA to realize the distributed computations and the user interface is developed to realize the job submission and job management locally/remotely. Taking the aero-elastic tailoring of a composite wing for optimization as an example, a set of Pareto solutions are obtained for the decision-maker. The numerical results show that the aileron reversal problem can be solved by adding the limited skin weight in this system. The algorithm can be used to solve complicated topology optimization for composite structures in engineering and the computation efficiency can be improved greatly by using the grid platform that aggregates numerous idle resources. 相似文献